Subject: Determining Mass Size for Lehman Seismometer From: "Gary Lindgren" gel@................. Date: Mon, 31 Mar 2008 17:40:48 -0700 How do I determine the mass size of the pendulum for a Lehman seismometer. Is there a method to the madness? Gary Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com cymonsplace.blogspot.com

How do I determine the mass size of the pendulum for a Lehman seismometer. = Is there a method to the madness?

Gary

 

Gary Lindgren

585 Lincoln Ave

Palo = Alto CA 94301

 

650-326-0655

 

www.blue-eagle-technologi= es.com

cymonsplace.blogspot.com=  

 

 

Subject: Re: Determining Mass Size for Lehman Seismometer From: lehmancj@........... Date: Tue, 1 Apr 2008 00:55:38 GMT > How do I determine the mass size of the pendulum for a Lehman seismometer. > Is there a method to the madness? > > Gary--just a note on the original determination of the mass. I chose a 5lb. piece of lead as it was available & handy. For the dimensions of the boom, the lead was not excessive weight, and seemed to be sufficient mass for stability, and was able to be supported by piano wire without undo fatigue. The system worked beyond our original expectations, but there have been modifications & improvements, so don't fear to experiment around with other suggestions that float by. A working design is empirical by nature--best wishes--Jim Lehman > > > > Gary Lindgren > > 585 Lincoln Ave > > Palo Alto CA 94301 > > > > 650-326-0655 > > > > www.blue-eagle-technologies.com > > cymonsplace.blogspot.com > > > > > > --------------------------------------------- This message was sent using Shentel WebMail. http://WebMail.Shentel.Net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Determining Mass Size for Lehman Seismometer From: ChrisAtUpw@....... Date: Mon, 31 Mar 2008 22:38:55 EDT In a message dated 2008/04/01, gel@................. writes: > How do I determine the mass size of the pendulum for a Lehman seismometer. > Is there a method to the madness? > Gary Hi Gary, There is method in the madness! The period of a pendulum is independant of the mass, since the gravitational attraction and the moment of inertia both depend on M ! But you need ~the maximum radius of gyration, so you make the mass several times larger than the weight of the arm on it's own. But you don't want to stress the suspension too much. A mass of 1 to about 5 lbs is generally OK. Lead is dense, but difficult to fasten, so I generally use brass. Avoid iron, which is magnetic. Hope that this helps! Regards, Chris Chapman In a me= ssage dated 2008/04/01, gel@................. writes:

How do I determine the mass siz= e of the pendulum for a Lehman seismometer. Is there a method to the madness= ?
Gary


Hi Gary,

       There is method in the madness!

       The period of a pendulum is independant= of the mass, since the gravitational attraction and the moment of inertia b= oth depend on M !

       But you need ~the maximum radius of gyr= ation, so you make the mass several times larger than the weight of the arm=20= on it's own. But you don't want to stress the suspension too much.  A m= ass of 1 to about 5 lbs is generally OK. Lead is dense, but difficult to fas= ten, so I generally use brass. Avoid iron, which is magnetic.

       Hope that this helps!

       Regards,

       Chris Chapman
Subject: Re: Determining Mass Size for Lehman Seismometer From: "Geoff" gmvoeth@........... Date: Tue, 1 Apr 2008 07:39:18 -0700 If you consider the science of external ballistics you will find the greater the mass and density the less effect air movemenr will have on it. Otherwise use a small mass several times the boom mass and put in all under a vacuum with magnetic damping. Static friction is the only nasty thing to deal with as I understand it. It tends to lock things into place till you get enough force to overcome it. If you do not have the ability to produce and maintain a vacuum I think a spherical shape may be the best for the mass. I have often thought it would be nice to have a very very sensitive bathroom scale and put a gallon of water on it then look for the noise level. Not sure of any of this it just seems common senseical :-) ----- Original Message ----- From: "Gary Lindgren" To: Sent: Monday, March 31, 2008 5:40 PM Subject: Determining Mass Size for Lehman Seismometer > How do I determine the mass size of the pendulum for a Lehman seismometer. > Is there a method to the madness? > > Gary > > > > Gary Lindgren > > 585 Lincoln Ave > > Palo Alto CA 94301 > > > > 650-326-0655 > > > > www.blue-eagle-technologies.com > > cymonsplace.blogspot.com > > > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Tiltmeter Electronics From: "Chuck Burch" cjburch@........... Date: Wed, 02 Apr 2008 20:43:27 -0700 I'm wondering about electronics for a tiltmeter with capacitive sensors I'm building. My current plan is to use a transformer coupled bridge, current-to-voltage amplifier, phase sensitive detector, followed by filter and final gain. I have a circuit diagram for this scheme, but it's circa 1970 and I assume it can be improved with modern chips. Any suggestions? Chuck Burch __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Tiltmeter Electronics From: ChrisAtUpw@....... Date: Wed, 2 Apr 2008 11:36:06 EDT In a message dated 2008/04/02, cjburch@........... writes: > I'm wondering about electronics for a tiltmeter with capacitive sensors I'm > building. > My current plan is to use a transformer coupled bridge, current-to-voltage > amplifier, > phase sensitive detector, followed by filter and final gain. I have a > circuit diagram for this scheme, but it's circa 1970 and I assume it can be > improved with modern chips. Hi Chuck, George Bush at ke6pxp@....... has done quite a lot of work on the Mercury Tiltmeter published by the Scientific American about then. The original circuit needs to be improved very considerably. I helped George over the design using an LTC1043 switched capacitor bridge. He has a website at http://ntweb.mcn.org/gbush/Tiltmeter/tiltmeter%20Main.html DON'T bother with the Nuts and Volts circuit. It does not work well. There is another seismometer / tiltmeter circuit using water, as opposed to mercury, which also works very well at FMES. Contact Dave Nelson at davefnelson@....... Design and circuits are available. Regards, Chris Chapman In a me= ssage dated 2008/04/02, cjburch@........... writes:

I'm wondering about electronics= for a tiltmeter with capacitive sensors I'm building. 
My current plan is to use a transformer coupled bridge, current-to-voltage a= mplifier,
phase sensitive detector, followed by filter and final gain.  I have a=20= circuit diagram for this scheme, but it's circa 1970 and I assume it can be=20= improved with modern chips. 


Hi Chuck,

       George Bush at ke6pxp@....... has done quite a lot of work on the Mercury&nbs= p; Tiltmeter published by the Scientific American about then. The original c= ircuit needs to be improved very considerably. I helped George over the desi= gn using an LTC1043 switched capacitor bridge.

       He has a website at http://ntweb.mcn.or= g/gbush/Tiltmeter/tiltmeter%20Main.html

       DON'T bother with the Nuts and Volts ci= rcuit. It does not work well.

       There is another seismometer / tiltmete= r circuit using water, as opposed to mercury, which also works very well at=20= FMES. Contact Dave Nelson at davefnelson@....... Design and circuits are ava= ilable.

       Regards,

       Chris Chapman
Subject: Question regarding leveling of vertical seismometer From: "Kay Wyatt" kwyatt@............. Date: Wed, 2 Apr 2008 12:22:33 -0700 Folks, A quick question regarding the leveling screws for a vertical = seismosmeter... If you look at the three leveling screws on the AS-1 seismometer at = http://www.amateurseismologist.com/, you see that there are two screws = on the end with the vertical support and one screw on the end near the = coil. It is obvious why only three screws are used. But is their a = reason for putting the single screw near the coil and not near the = vertical support. Also, wouldn't there be greater stability if the = single screw was actually a fixed pin, leaving the other two to be = adjustable screws? =20 Just wondering before I drill the base in my next vertical seismometer. Thanks, Kay Wyatt
Folks,
 
A quick question regarding the leveling screws = for a=20 vertical seismosmeter...
 
If you look at the three leveling screws on the = AS-1=20 seismometer at http://www.amateurseismologi= st.com/,=20 you see that there are two screws on the end with the vertical support = and one=20 screw on the end near the coil.  It is obvious why only three = screws are=20 used.  But is their a reason for putting the single screw near the = coil and=20 not near the vertical support.  Also, wouldn't there be greater = stability=20 if the single screw was actually a fixed pin, leaving the other two to = be=20 adjustable screws? 
 
Just wondering before I drill the base in = my next=20 vertical seismometer.
 
Thanks,
Kay Wyatt
 
 
Subject: Re: Question regarding leveling of vertical seismometer From: ChrisAtUpw@....... Date: Wed, 2 Apr 2008 16:18:00 EDT In a message dated 2008/04/02, kwyatt@............. writes: > If you look at the three leveling screws on the AS-1 seismometer at > http://www.amateurseismologist.com/, you see that there are two screws on the end > with the vertical support and one screw on the end near the coil. It is > obvious why only three screws are used. But is their a reason for putting the > single screw near the coil and not near the vertical support. Also, wouldn't > there be greater stability if the single screw was actually a fixed pin, leaving > the other two to be adjustable screws? > > Just wondering before I drill the base in my next vertical seismometer. Hi Kay, It shouldn't matter, but it is generally easier to put the lateral adjustment screws either side of the vertical support column and the longitudinal adjustment at the end of the arm. You have 'free' space here. I suggest the you make all three mounting screws of identical construction. If you have one peg leg you will have the problem of matching it's expansion with the other two. This is not too important for vertical instruments, but it is very important on a Lehman. Also, you generally get presented with a site of unknown slope direction. Being able to adjust all three screws is an advantage. I use a fairly thick baseplate and stainless steel bolts, nuts and washers. I drill the hole the same nominal OD as the bolt. I stick a SS nut on the underside of the basplate with two component acrylic glue eg Devcon Plastic Welder S-220 22045. You can also buy 'nut-serts' which you press into suitable holes with a vice or a press. I centre drill the end of the bolts and stick a suitable OD SS ball bearing in the V. Alternatively, you can file the end of the bolt to a cone with a small domed end. This helps prevent the seismometer position wandering as you make adjustments. I thread an ordinary nut onto the bolt, add a wavy washer and screw this into the top of the frame. After adjusting the levels I tighten compress the wavy washer with the free top nut. This largely prevents any creep due to differential expansion. I also use three 2" square x 1/8" thick SS ground plates. What you MUST NOT do is to use bolts and nuts / threaded holes of DIFFERENT materials, with different expansion coefficients. This will ~guarantee creep / drift problems. Regards, Chris Chapman In a me= ssage dated 2008/04/02, kwyatt@............. writes:

If you look at the three leveli= ng screws on the AS-1 seismometer at http://www.amateurseismologist.com/, you see that there are two= screws on the end with the vertical support and one screw on the end near t= he coil.  It is obvious why only three screws are used.  But is th= eir a reason for putting the single screw near the coil and not near the ver= tical support.  Also, wouldn't there be greater stability if the single= screw was actually a fixed pin, leaving the other two to be adjustable scre= ws? 

Just wondering before I drill the base in my next vertical seismometer.

Hi Kay,

       It shouldn't matter, but it is generall= y easier to put the lateral adjustment screws either side of the vertical su= pport column and the longitudinal adjustment at the end of the arm. You have= 'free' space here.
       I suggest the you make all three mounti= ng screws of identical construction. If you have one peg leg you will have t= he problem of matching it's expansion with the other two. This is not too im= portant for vertical instruments, but it is very important on a Lehman.
       Also, you generally get presented with=20= a site of unknown slope direction. Being able to adjust all three screws is=20= an advantage.
       I use a fairly thick baseplate and stai= nless steel bolts, nuts and washers. I drill the hole the same nominal OD as= the bolt. I stick a SS nut on the underside of the basplate with two compon= ent acrylic glue eg Devcon Plastic Welder S-220 22045.
       You can also buy 'nut-serts' which you=20= press into suitable holes with a vice or a press.
       I centre drill the end of the bolts and= stick a suitable OD SS ball bearing in the V. Alternatively, you can file t= he end of the bolt to a cone with a small domed end. This helps prevent the=20= seismometer position wandering as you make adjustments.
       I thread an ordinary nut onto the bolt,= add a wavy washer and screw this into the top of the frame. After adjusting= the levels I tighten compress the wavy washer with the free top nut. This l= argely prevents any creep due to differential expansion.
       I also use three 2" square x 1/8" thick= SS ground plates.
       What you MUST NOT do is to use bolts an= d nuts / threaded holes of DIFFERENT materials, with different expansion coe= fficients. This will ~guarantee creep / drift problems.

       Regards,

       Chris Chapman
Subject: Re: Question regarding leveling of vertical seismometer From: John Lahr johnjan@........ Date: Wed, 02 Apr 2008 23:10:26 -0700 Hi Kay, The problem with a fixed pin at one end is that to change to level in the long direction, both of the other screws would need to be turned. This would probably mess up the tilt in the short direction. With three screws, the short-direction tilt and the long-direction tilt can be adjusted independently. Cheers, John At 12:22 PM 4/2/2008, you wrote: >Folks, > >A quick question regarding the leveling screws for a vertical seismosmeter... > >If you look at the three leveling screws on the AS-1 seismometer at >http://www.amateurseismologist.com/, >you see that there are two screws on the end with the vertical >support and one screw on the end near the coil. It is obvious why >only three screws are used. But is their a reason for putting the >single screw near the coil and not near the vertical support. Also, >wouldn't there be greater stability if the single screw was actually >a fixed pin, leaving the other two to be adjustable screws? > >Just wondering before I drill the base in my next vertical seismometer. > >Thanks, >Kay Wyatt > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Question regarding leveling of vertical seismometer From: Charles Patton charles.r.patton@........ Date: Thu, 03 Apr 2008 10:41:07 -0700 Hi John, Not necessarily. The geometry used for mirror mounts in optical bench work is that the fixed point is at the intersection of two lines at right angles to one another. The two screws are then on each of the lines respectively. That way the screws do not interact, i.e., they cause only orthogonal tilt on their particular axis. So translating that to a seismometer, put the fixed pin near the pivot point of the boom and offside in the short dimension (perpendicular to the boom (if a Lehman style, but similar rules for a vertical) -- probably in one corner) Place one screw way down the base on a line through the fixed pin and parallel to the boom. This will become the leveling screw. Place the other screw on a line at right angles to the fixed point and the just placed screw (probably in the corner across the pivot. This is now the tilt. The only other trick is to put enough weight on the base so that the center-of-mass is within the triangle formed by the fixed point and two screws (or use a long, triangular shaped base where all the parts are within the triangle. Mirror mounts typically use springs to hold the mounts together, rather than gravity) So even if you use three screws, this geometry will make life much easier when adjusting as there won't be axis interactions when doing the final adjustments using only the two screws at the ends of the right angle. Refinements are to make the design fully kinematic by using a tetrahedral divot for the fixed point ball end to rest in, a tri-angular groove aligned along the line of the fixed point and the screw ball end, and finally a flat plate for the final screw ball end. This constrains the whole fixture so it doesn't slide or twist on the resting base. Charles Patton John Lahr wrote: > Hi Kay, > > The problem with a fixed pin at one end is that to change to level in > the long direction, both of the other screws would need to be turned. > This would probably mess up the tilt in the short direction. > > With three screws, the short-direction tilt and the long-direction tilt > can be adjusted independently. > > Cheers, > John > > At 12:22 PM 4/2/2008, you wrote: >> Folks, >> >> A quick question regarding the leveling screws for a vertical >> seismosmeter... >> >> If you look at the three leveling screws on the AS-1 seismometer at >> http://www.amateurseismologist.com/, >> you see that there are two screws on the end with the vertical support >> and one screw on the end near the coil. It is obvious why only three >> screws are used. But is their a reason for putting the single screw >> near the coil and not near the vertical support. Also, wouldn't there >> be greater stability if the single screw was actually a fixed pin, >> leaving the other two to be adjustable screws? >> >> Just wondering before I drill the base in my next vertical seismometer. >> >> Thanks, >> Kay Wyatt >> >> > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Question regarding leveling of vertical seismometer From: ChrisAtUpw@....... Date: Thu, 3 Apr 2008 14:19:23 EDT In a message dated 2008/04/03, charles.r.patton@........ writes: > The only other trick is to put enough weight on the base > so that the center-of-mass is within the triangle formed by the fixed > point and two screws (or use a long, triangular shaped base where all > the parts are within the triangle. Hi Charles, This is not usually done. The base is always flexible to some extent and having an offset centre of mass / anisotropic flexure may not be exactly helpful. Regards, Chris Chapman In a me= ssage dated 2008/04/03, charles.r.patton@........ writes:

The only other trick is to put=20= enough weight on the base
so that the center-of-mass is within the triangle formed by the fixed
point and two screws (or use a long, triangular shaped base where all
the parts are within the triangle.


Hi Charles,
      
       This is not usually done. The base is a= lways flexible to some extent and having an offset centre of mass / anisotro= pic flexure may not be exactly helpful.

       Regards,

       Chris Chapman
Subject: Shake table From: "Kay Wyatt" kwyatt@............. Date: Fri, 4 Apr 2008 09:57:58 -0700 Folks, Thanks for the feedback on the leveling screws for my seismometer. Now here is a question regarding a shake table. =20 I currently have a small shake table that has a 10" base plate which I = use in the public schools to help kids understand the relationship of = building structure and materials to earthquake damage. I divide the = kids up into teams to construct their "buildings" and then individually = set them on the shake table. Because only one building can be tested at = a time it is more time consuming and less "fun" for the kids because = they can't easily see how their building measures up to another team's = building. So, I am constructing a larger shake table with a 30" base that can hold = four buildings. This lets a class divide up into four teams and then = the entire class can watch their buildings shake at once. Say an actual building has a footprint of 100 feet square. Relative to = a model building which has a footprint of 12 inches square, the width is = a factor of 100. I have a variable frequency motor to which I am = attaching off center cams to create the vibration movement. Springs = pull back the base towards the drive shaft with the cams. So, here is my question. Has anybody experimented with a shake table of = this size? What displacements should I design the cams to create? I = could use different size cams to create different "magnitude" = earthquakes. Also, what frequencies should I set the motor to run. Thanks for any help that you might offer. Kay
Folks,
 
Thanks for the feedback on the leveling screws = for my=20 seismometer.
 
Now here is a question regarding a shake=20 table.  
 
I currently have a small shake table that has a = 10" base=20 plate which I use in the public schools to help kids understand the = relationship=20 of building structure and materials to earthquake damage.  I divide = the=20 kids up into teams to construct their "buildings" and then individually = set them=20 on the shake table.  Because only one building can be tested at a = time it=20 is more time consuming and less "fun" for the kids because they can't = easily see=20 how their building measures up to another team's building.
 
So, I am constructing a larger shake table with = a 30" base=20 that can hold four buildings.  This lets a class divide up into = four teams=20 and then the entire class can watch their buildings shake at = once.
 
Say an actual building has a footprint of 100 = feet=20 square.  Relative to a model building which has a footprint of 12 = inches=20 square, the width is a factor of 100.  I have a variable frequency = motor to=20 which I am attaching off center cams to create the vibration = movement. =20 Springs pull back the base towards the drive shaft with the = cams.
 
So, here is my question.  Has anybody = experimented=20 with a shake table of this size?  What displacements should I = design the=20 cams to create?  I could use different size cams to create = different=20 "magnitude" earthquakes.  Also, what frequencies should I set the = motor to=20 run.
 
Thanks for any help that you might = offer.
 
Kay
 
Subject: Re: Shake table From: ChrisAtUpw@....... Date: Fri, 4 Apr 2008 15:56:19 EDT In a message dated 2008/04/04, kwyatt@............. writes: > So, I am constructing a larger shake table with a 30" base that can hold > four buildings. This lets a class divide up into four teams and then the > entire class can watch their buildings shake at once. Hi Kay, Something that size could be quite heavy. Consider foam filled buiilding / wall sheet with an Al L angle surround and four vertical foil flexures? You can also buy metal + rubber vibration isolation mountings.You can get Celotex up to at least 3" thick? This has a thin glass/resin skin. Apart from variable speed motors you can also get 'floor shakers', which are a very heavy magnet + coil driver system. We use them for testing seismometers & geophones. Alternatively, you could use a coil of wire and NdFeB magnets. Maybe drive it with a LF oscillator and an audio amplifier? The professional shake tables may use an electromagnetic drive controlled by a distance transducer. You can vary the frequency and the amplitude. Regards, Chris Chapman In a me= ssage dated 2008/04/04, kwyatt@............. writes:

So, I am constructing a larger=20= shake table with a 30" base that can hold four buildings.  This lets a=20= class divide up into four teams and then the entire class can watch their bu= ildings shake at once.


Hi Kay,

       Something that size could be quite heav= y. Consider foam filled buiilding / wall sheet with an Al L angle surround a= nd four vertical foil flexures? You can also buy metal + rubber vibration is= olation mountings.You can get Celotex up to at least 3" thick? This has a th= in glass/resin skin.
       Apart from variable speed motors you ca= n also get 'floor shakers', which are a very heavy magnet + coil driver syst= em. We use them for testing seismometers & geophones. Alternatively, you= could use a coil of wire and NdFeB magnets. Maybe drive it with a LF oscill= ator and an audio amplifier?
       The professional shake tables may use a= n electromagnetic drive controlled by a distance transducer. You can vary th= e frequency and the amplitude.

       Regards,

       Chris Chapman
Subject: Re: Shake table From: John Lahr johnjan@........ Date: Sat, 05 Apr 2008 03:01:17 -0700 Hi Kay, This sounds like a great project. I would really like to post some pictures to my web site, along with construction details, when you're done. I've always used variable frequency, rather than amplitude. It's easier to do and let's the resonant period of the model be determined. The best frequency (the one that causes damage!) will depend on the height and construction of each model. It's best if there is a weight requirement, in that each model must carry a considerable weight on the roof. This could be considered an air conditioner unit for the building or some other machinery. One thing to avoid is providing too much time/material so that the buildings are indestructible! A teacher sent me a video of his class testing their models and they were so strong that not much happened on the shake table. One actually fell on the floor and was not damaged! Cheers, John At 09:57 AM 4/4/2008, you wrote: >Folks, > >Thanks for the feedback on the leveling screws for my seismometer. > >Now here is a question regarding a shake table. > >I currently have a small shake table that has a 10" base plate which >I use in the public schools to help kids understand the relationship >of building structure and materials to earthquake damage. I divide >the kids up into teams to construct their "buildings" and then >individually set them on the shake table. Because only one building >can be tested at a time it is more time consuming and less "fun" for >the kids because they can't easily see how their building measures >up to another team's building. > >So, I am constructing a larger shake table with a 30" base that can >hold four buildings. This lets a class divide up into four teams >and then the entire class can watch their buildings shake at once. > >Say an actual building has a footprint of 100 feet square. Relative >to a model building which has a footprint of 12 inches square, the >width is a factor of 100. I have a variable frequency motor to >which I am attaching off center cams to create the vibration >movement. Springs pull back the base towards the drive shaft with the cams. > >So, here is my question. Has anybody experimented with a shake >table of this size? What displacements should I design the cams to >create? I could use different size cams to create different >"magnitude" earthquakes. Also, what frequencies should I set the motor to run. > >Thanks for any help that you might offer. > >Kay > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Electronic components From: tchannel1@............ Date: Sat, 5 Apr 2008 09:35:15 -0600 Hi Folks, Could anyone recommend a wed site where I can purchases = electronic bits and pieces, ic's, relays, etc, and has little or no = minimum order? I did Goggle it but I am not having much luck. Thanks, Ted
Hi Folks,  Could anyone recommend = a wed site=20 where I can purchases electronic bits and pieces, ic's, = relays, etc, and=20 has little or no minimum order?
 
I did Goggle it but I am not having = much=20 luck.
 
 
Thanks, Ted
Subject: Re: Electronic components From: "Jerry Payton" gpayton880@....... Date: Sat, 5 Apr 2008 10:48:31 -0500 Hi Ted, The Mad Scientist at work again, huh. (Just joking) You might try www.mouser.com or www.digikey.com , depending upon what you are looking for. We also used http://www.allelectronics.com/ before too. Regards, Jerry ----- Original Message ----- From: tchannel1@............ To: psn Sent: Saturday, April 05, 2008 10:35 AM Subject: Electronic components Hi Folks, Could anyone recommend a wed site where I can purchases electronic bits and pieces, ic's, relays, etc, and has little or no minimum order? I did Goggle it but I am not having much luck. Thanks, Ted
Hi Ted,
 
The Mad Scientist at work again, huh.  (Just joking)
 
You might try  www.mouser.com  or  www.digikey.com , depending = upon what you=20 are looking for.  We also used  http://www.allelectronics.com/ =20 before too.
 
Regards,
Jerry
 
 
----- Original Message -----=20
From: tchannel1@............
To: psn
Sent: Saturday, April 05, 2008 10:35 AM
Subject: Electronic components

Hi Folks,  Could anyone recommend = a wed site=20 where I can purchases electronic bits and pieces, ic's, = relays, etc, and=20 has little or no minimum order?
 
I did Goggle it but I am not having = much=20 luck.
 
 
Thanks, Ted
Subject: Whip antenna From: tchannel1@............ Date: Sat, 5 Apr 2008 10:01:11 -0600 Hi Folks, If I had a 36" whip antenna, just a piece of spring steel rod, = with a small mass on the tip, how much would the tip move during a = earthquake? I know that is just a general question, and it would depend on many = factors. Let's say the size of the event was 6.0M, 1000 mile away. = This event would be recorded by all three of my sensors. The movement = of sensor's pendulum or vertical spring during this type of event would = probably not be noticeable to the eye. If the event was a large one, = then surely it would be noticeable to the eye, perhaps even 1/8" or = more. I am still trying to come up with a Earthquake Directional Device. I = have seen articles on the Chinese versions, and turn of the century = devices which used a variety of approaches, where a normal pendulum or = even a "Wipe Antenna" / inverted pendulum would be set in motion and = make contact with a circuit. I know such devices would work in = California, but I don't know how small or weak events would work. =20 My thinking is, if I just use the motion of a "Whip Antenna" to close a = contact, it would not record much, unless I could move the two points of = contact to within the thickness of a human hair. I know I could use a magnet/coil and the device would work on most all = earthquakes, presently recordable, but I don't want to dismiss these old = approaches either. Just wanted to get an opinion. Thanks, Ted
Hi Folks, If I had a 36" whip antenna, = just a piece=20 of spring steel rod, with a small mass on the tip, how much would the = tip move=20 during a earthquake?
I know that is just a general question, = and it=20 would depend on many factors.   Let's say the size of the = event was=20 6.0M, 1000 mile away.  This event would be recorded by all three of = my=20 sensors.  The movement of sensor's pendulum or vertical spring = during=20 this type of event would probably not be noticeable to the eye.  If = the=20 event was a large one, then surely it would be noticeable to the eye, = perhaps=20 even 1/8" or more.
 
I am still trying to come up with a = Earthquake=20 Directional Device.   I have seen articles on the Chinese = versions,=20 and turn of the century devices which used a variety of approaches, = where a=20 normal pendulum or even a  "Wipe Antenna" / inverted pendulum = would be=20 set in motion and make contact with a circuit.   I know such = devices=20 would work in California, but I don't know how small or weak events = would=20 work. 
 
My thinking is, if I just use the = motion of a "Whip=20 Antenna" to close a contact, it would not record much, unless I could = move the=20 two points of contact to within the thickness of a human = hair.
 
I know I could use a magnet/coil and = the device=20 would work on most all earthquakes, presently recordable, but I don't = want to=20 dismiss these old approaches either.
 
Just wanted to get an = opinion.
 
Thanks, Ted
 
Subject: Re: Electronic components From: "Erich Kern" efkern@............. Date: Sat, 5 Apr 2008 09:32:17 -0700 Ted, Send me a list (off-list, to my email adress) of what you need and I'll = email you a price quote + postage. All new parts.=20 Erich Kern Murrieta, Calif.=20 ----- Original Message -----=20 From: tchannel1@............... To: psn=20 Sent: Saturday, April 05, 2008 8:35 AM Subject: Electronic components Hi Folks, Could anyone recommend a wed site where I can purchases = electronic bits and pieces, ic's, relays, etc, and has little or no = minimum order? I did Goggle it but I am not having much luck. Thanks, Ted
 
Ted,
 
Send me a list (off-list, to my email adress) of = what you=20 need and I'll email you a price quote + postage. All new parts. =
 
Erich Kern
Murrieta, Calif.
 
 
----- Original Message -----=20
From: tchannel1@............
To: psn
Sent: Saturday, April 05, 2008 8:35 AM
Subject: Electronic components

Hi Folks,  Could anyone recommend = a wed site=20 where I can purchases electronic bits and pieces, ic's, = relays, etc, and=20 has little or no minimum order?
 
I did Goggle it but I am not having = much=20 luck.
 
 
Thanks, Ted
Subject: RE: Electronic components From: "Keith Payea" kpayea@.............. Date: Sat, 5 Apr 2008 09:35:27 -0700 Ted: Others have mentioned DigiKey and Mouser. I also use Jameco www.jameco.com for small orders. Keith _____ From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of tchannel1@............ Sent: Saturday, April 05, 2008 8:35 AM To: psn Subject: Electronic components Hi Folks, Could anyone recommend a wed site where I can purchases electronic bits and pieces, ic's, relays, etc, and has little or no minimum order? I did Goggle it but I am not having much luck. Thanks, Ted
Ted:
 
Others have mentioned DigiKey and Mouser.  = I also use=20 Jameco www.jameco.com for small=20 orders.
 
    Keith


From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of=20 tchannel1@............
Sent: Saturday, April 05, 2008 8:35 = AM
To: psn
Subject: Electronic=20 components

Hi Folks,  Could anyone recommend = a wed site=20 where I can purchases electronic bits and pieces, ic's, = relays, etc, and=20 has little or no minimum order?
 
I did Goggle it but I am not having = much=20 luck.
 
 
Thanks, Ted
Subject: RE: Electronic components From: Brad Douglas rez@.................. Date: Sat, 05 Apr 2008 16:58:06 +0000 BTW, if you're in the SF Bay area, Jameco does will-call and walk-ins. Not everything is immediately available (different warehouse), but much of their stock is. DigiKey can be hard on shipping expenses, but they are the "gold standard". Mouser can be cheaper, but does not come close to carrying DigiKey's vast stock. Hope this helps the search for parts. On Sat, 2008-04-05 at 09:35 -0700, Keith Payea wrote: > Ted: > > Others have mentioned DigiKey and Mouser. I also use Jameco > www.jameco.com for small orders. -- 73, de Brad KB8UYR/6 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Whip antenna From: ChrisAtUpw@....... Date: Sat, 5 Apr 2008 16:20:06 EDT In a message dated 2008/04/05, tchannel1@............ writes: > Hi Folks, If I had a 36" whip antenna, just a piece of spring steel rod, > with a small mass on the tip, how much would the tip move during a earthquake? Hi Ted, The mass should ideally NOT move at all ! It is the Earth which moves. See the graphs at http://jclahr.com/science/psn/magnitude.html for actual amplitides of phases. Regards, Chris Chapman In a me= ssage dated 2008/04/05, tchannel1@............ writes:

Hi Folks, If I had a 36" whip a= ntenna, just a piece of spring steel rod, with a small mass on the tip, how=20= much would the tip move during a earthquake?


Hi Ted,

       The mass should ideally NOT move at all= ! It is the Earth which moves. See the graphs at http://jclahr.com/science/= psn/magnitude.html for actual amplitides of phases.

       Regards,

       Chris Chapman
Subject: Re: Electronic components From: "Geoff" gmvoeth@........... Date: Sat, 5 Apr 2008 16:51:22 -0700 NOPE...Mad ENGINEER or Technician like ME. Did you know they do not teach law to up and coming engineers at the Universities and that those Engineers are relatively frightened of legal peoples ?? I understand in some countries if you have no degrees in the right field then practicing say like seismology might be technically illegal. I think thats why the Counter Intelligence peoples can get away with murder. They dont even know or care about the laws such as INFERNAL DEVICES. Just care about the moneys they make doing their shady work and raising their equally crooked families. I think seismology is one of the more harmless amateur sciences to be in unless it becomes somehow a real live social event. Possibly a company called Allied or Newark Electronics but its best if you can afford it to go with prebuilt systems. Complete systems unless you want to know all the technical details. The cost of parts are totally outrageous today and you almost need a microscope and surgeon tools to work with them. The EARLY 1980s saw a reduction in general industrial inventories of electronics that drove prices out of sight for little/small quantity parts. USe kits where ever possible. :-) ----- Original Message ----- From: "Jerry Payton" To: Sent: Saturday, April 05, 2008 8:48 AM Subject: Re: Electronic components > Hi Ted, > > The Mad Scientist at work again, huh. (Just joking) > > You might try www.mouser.com or www.digikey.com , depending upon what you > are looking for. We also used http://www.allelectronics.com/ before too. > > Regards, > Jerry > > > ----- Original Message ----- > From: tchannel1@............ > To: psn > Sent: Saturday, April 05, 2008 10:35 AM > Subject: Electronic components > > > Hi Folks, Could anyone recommend a wed site where I can purchases > electronic bits and pieces, ic's, relays, etc, and has little or no minimum > order? > > I did Goggle it but I am not having much luck. > > > Thanks, Ted > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Whip antenna From: "Geoff" gmvoeth@........... Date: Sat, 5 Apr 2008 17:02:21 -0700 Yesireee, The mass serves as a reference point against which the earth moves. But only frequencies at or above the point of resonance as I understand. Below resonance the mass starts to move with the Earth and more so as the frequency lowers. You must somehow lower gravity accelerational effects to the point where you get a 4 second period before you can easily fit the electronics to the sensor wuthout a lot of equalization to get a flat response ove the range of interest. Possibly 1 to 3ft/s^2 instead of 32ft/s^2 . How you do this is the real trick for a spring and a mass. :-) :-| :-O :-( ----- Original Message ----- From: To: Sent: Saturday, April 05, 2008 1:20 PM Subject: Re: Whip antenna > In a message dated 2008/04/05, tchannel1@............ writes: > >> Hi Folks, If I had a 36" whip antenna, just a piece of spring steel rod, >> with a small mass on the tip, how much would the tip move during a earthquake? > > Hi Ted, > > The mass should ideally NOT move at all ! It is the Earth which moves. > See the graphs at http://jclahr.com/science/psn/magnitude.html for actual > amplitides of phases. > > Regards, > > Chris Chapman > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: seismometer mass movement From: Randall Peters PETERS_RD@.......... Date: Mon, 07 Apr 2008 09:41:42 -0400 Geoff, Your understanding is indeed correct. Only for drive frequencies above the natural frequency of the instrument does the mass not move relative to the inertial frame (instrument behaving as a vibrometer). At frequencies below the natural frequency, it is the motion of the mass relative to the inertial frame that limits sensitivity. By making the natural frequency lower, the amplitude of this mass motion decreases, which increases the sensitivity (and is the reason for the low frequency sensitivity to displacement being proportional to the square of the natural period). At very low drive frequency the pendulum aligns itself with the vector sum of the earth's field vector g and the negative of the drive acceleration vector a; i.e., the angle of deflection in radians is given by -a/g (for a small compared to g). If there were no mass motion at low drive frequency, the pendulum would have no acceleration response whatsoever. Instead of the small deflection angle in radians being -a/g, zero inertial mass motion would require the angle to be identically zero. One can demonstrate the difference between high frequency stationary mass and low frequency moving mass very easily with a simple pendulum (a nut and a string). Hold the pendulum with your hand at the top of the string supporting the nut on the other end. Move your hand rapidly back and forth and you will see that the bob doesn't move--being at rest with respect to the room but with a motion relative to your hand that is out of phase by 180 degrees. Now move the string back and forth slowly and you will see the bob is in phase (in a relative sense) with your hand's motion (and it most certainly is not at rest relative to the room). Randall Subject: correction--mass movement From: Randall Peters PETERS_RD@.......... Date: Mon, 07 Apr 2008 09:58:23 -0400 If the mass did not move at very low drive frequencies, the deflection would be non-physically huge instead of my statement that is would be zero. Subject: RE: Shake table From: felipe luevanos luevanos felicaribe5@........... Date: Mon, 7 Apr 2008 20:17:40 +0000 Hi, =20 =20 What you are building is nice; have you tried having inverted pendulums sup= ported by a 2x4 piece of wood all of the pendulums in different lengths wit= h lets say foam balls of equal or different masses, then you shake the tabl= e with your hands at diffrent frequencies and observe the totally different= responses of each (ball/mass/pendulum)? =20 Good luck =20 =20 Felipe Luevanos From: kwyatt@................ psn-l@...................... Shake tableDate:= Fri, 4 Apr 2008 09:57:58 -0700 Folks, =20 Thanks for the feedback on the leveling screws for my seismometer. =20 Now here is a question regarding a shake table. =20 =20 I currently have a small shake table that has a 10" base plate which I use = in the public schools to help kids understand the relationship of building = structure and materials to earthquake damage. I divide the kids up into te= ams to construct their "buildings" and then individually set them on the sh= ake table. Because only one building can be tested at a time it is more ti= me consuming and less "fun" for the kids because they can't easily see how = their building measures up to another team's building. =20 So, I am constructing a larger shake table with a 30" base that can hold fo= ur buildings. This lets a class divide up into four teams and then the ent= ire class can watch their buildings shake at once. =20 Say an actual building has a footprint of 100 feet square. Relative to a m= odel building which has a footprint of 12 inches square, the width is a fac= tor of 100. I have a variable frequency motor to which I am attaching off = center cams to create the vibration movement. Springs pull back the base t= owards the drive shaft with the cams. =20 So, here is my question. Has anybody experimented with a shake table of th= is size? What displacements should I design the cams to create? I could u= se different size cams to create different "magnitude" earthquakes. Also, = what frequencies should I set the motor to run. =20 Thanks for any help that you might offer. =20 Kay =20 _________________________________________________________________ Connect to the next generation of MSN Messenger=A0 http://imagine-msn.com/messenger/launch80/default.aspx?locale=3Den-us&sourc= e=3Dwlmailtagline= Hi,
 
 
What you are building is nice; have you tried having inverted pendulums sup= ported by a 2x4 piece of wood all of the pendulums in different lengths wit= h lets say foam balls of equal or different masses, then you shake the tabl= e with your hands at diffrent frequencies and observe the totally different= responses of each (ball/mass/pendulum)?
 
Good luck
 
 
Felipe Luevanos



From: kwyatt@.............
To: psn-l@..............
Subject: Shake ta= ble
Date: Fri, 4 Apr 2008 09:57:58 -0700

Folks,
 
Thanks for the feedback on the leveling screws for = my seismometer.
 
Now here is a question regarding a shake table.&nbs= p; 
 
I currently have a small shake table that has a 10"= base plate which I use in the public schools to help kids understand the r= elationship of building structure and materials to earthquake damage. = I divide the kids up into teams to construct their "buildings" and then in= dividually set them on the shake table.  Because only one building can= be tested at a time it is more time consuming and less "fun" for the kids = because they can't easily see how their building measures up to another tea= m's building.
 
So, I am constructing a larger shake table with a 3= 0" base that can hold four buildings.  This lets a class divide up int= o four teams and then the entire class can watch their buildings shake at o= nce.
 
Say an actual building has a footprint of 100 feet = square.  Relative to a model building which has a footprint of 12 inch= es square, the width is a factor of 100.  I have a variable frequency = motor to which I am attaching off center cams to create the vibration movem= ent.  Springs pull back the base towards the drive shaft with the cams= ..
 
So, here is my question.  Has anybody experime= nted with a shake table of this size?  What displacements should I des= ign the cams to create?  I could use different size cams to create dif= ferent "magnitude" earthquakes.  Also, what frequencies should I set t= he motor to run.
 
Thanks for any help that you might offer.
 
Kay
 


Connect to the next generation of= MSN Messenger=A0 Get it now= ! = Subject: Re: Shake table From: ChrisAtUpw@....... Date: Mon, 7 Apr 2008 18:23:23 EDT In a message dated 2008/04/07, felicaribe5@........... writes: > What you are building is nice; have you tried having inverted pendulums > supported by a 2x4 piece of wood all of the pendulums in different lengths with > lets say foam balls of equal or different masses, then you shake the table > with your hands at diffrent frequencies and observe the totally different > responses of each (ball/mass/pendulum)? Hi Felipe, This works fine as a simple demonstration, but it doesn't capture the attention of students the way that having them build four model 'buildings' and then see them collapse in sequence can. Most students will not think of a real tall building as something which can and does oscillate and fall to pieces during an Earthquake. Regards, Chris Chapman In a me= ssage dated 2008/04/07, felicaribe5@........... writes:

What you are building is nice;=20= have you tried having inverted pendulums supported by a 2x4 piece of wood al= l of the pendulums in different lengths with lets say foam balls of equal or= different masses, then you shake the table with your hands at diffrent freq= uencies and observe the totally different responses of each (ball/mass/pendu= lum)?


Hi Felipe,

       This works fine as a simple demonstrati= on, but it doesn't capture the attention of students the way that having the= m build four model 'buildings' and then see them collapse in sequence can. <= BR>        Most students will not think of a real=20= tall building as something which can and does oscillate and fall to pieces d= uring an Earthquake.

       Regards,

       Chris Chapman
Subject: Article On Microseisms From: Bob Hancock carpediem1@......... Date: Thu, 10 Apr 2008 19:32:06 -0700 The link is to an article on microseisms http://earthobservatory.nasa.gov/Newsroom/NasaNews/2008/2008030726263.html Article On Microseisms The l= ink is to an article on microseisms


    
http://earthobservatory.nasa.gov/Newsro= om/NasaNews/2008/2008030726263.html
 


Subject: Re: Article On Microseisms From: "Geoff" gmvoeth@........... Date: Fri, 11 Apr 2008 05:29:47 -0700 Interesting, I have noticed a significant increase in the magnitude of such Microseisms just hours preceeding a major weather front here in Arizona. I used to think it might relate to winds hitting the mountains but according to this it must be wave interaction in the Pacific Ocean. ----- Original Message ----- From: "Bob Hancock" To: "PSN" Sent: Thursday, April 10, 2008 7:32 PM Subject: Article On Microseisms > The link is to an article on microseisms > > > > http://earthobservatory.nasa.gov/Newsroom/NasaNews/2008/2008030726263.html > > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Article On Microseisms From: ChrisAtUpw@....... Date: Fri, 11 Apr 2008 09:46:11 EDT In a message dated 2008/04/11, gmvoeth@........... writes: > I have noticed a significant increase in the magnitude of such Microseisms > just hours preceeding a major weather front here in Arizona. > I used to think it might relate to winds hitting the mountains but according > to this it must be wave interaction in the Pacific Ocean. Hi Geoff, Those were probably due to pressure noise on the weather front. They can be quite noisy. Note that there are several places in the ocean which generate microseisms. The news article referreed to only one. The shelving bottom to the west of Norway is another and there are others in the Pacific. Regards, Chris Chapman In a me= ssage dated 2008/04/11, gmvoeth@........... writes:

I have noticed a significant in= crease in the magnitude of such Microseisms
just hours preceeding a major weather front here in Arizona.
I used to think it might relate to winds hitting the mountains but according= to this it must be wave interaction in the Pacific Ocean.


Hi Geoff,

       Those were probably due to pressure noi= se on the weather front. They can be quite noisy.

       Note that there are several places in t= he ocean which generate microseisms. The news article referreed to only one.= The shelving bottom to the west of Norway is another and there are others i= n the Pacific.

       Regards,

       Chris Chapman
Subject: Re: Article On Microseisms From: Bob Hancock carpediem1@......... Date: Fri, 11 Apr 2008 07:12:12 -0700 Hi Chris - As you said, microseisms are generated world wide when ocean waves strike shore. The strength of the microseisms are largely dependent upon the size of the waves that come ashore. The US Navy Fleet Numerical Meteorology and Oceanography Center - https://www.fnmoc.navy.mil/public/ publishes charts with current and projected ocean wave height worldwide and regional. This web site is a good place to start with when you see microseisms. You can often see the microseisms from large oceanic storms at long distances. East Coast USA hurricanes are very visible on West Coast USA seismic stations, and are probably also visible in Europe. Cheers, Bob Hancock On 4/11/08 6:46 AM, "ChrisAtUpw@......." wrote: > In a message dated 2008/04/11, gmvoeth@........... writes: > >> I have noticed a significant increase in the magnitude of such Microseisms >> just hours preceeding a major weather front here in Arizona. >> I used to think it might relate to winds hitting the mountains but according >> to this it must be wave interaction in the Pacific Ocean. > > > Hi Geoff, > > Those were probably due to pressure noise on the weather front. They > can be quite noisy. > > Note that there are several places in the ocean which generate > microseisms. The news article referreed to only one. The shelving bottom to > the west of Norway is another and there are others in the Pacific. > > Regards, > > Chris Chapman Re: Article On Microseisms Hi Ch= ris -

As you said, microseisms are generated world wide when ocean waves strike s= hore.  The strength of the microseisms are largely dependent upon the s= ize of the waves that come ashore.

The US Navy Fleet Numerical Meteorology and Oceanography Center -  htt= ps://www.fnmoc.navy.mil/public/

publishes charts with current and projected ocean wave height worldwide and= regional.  This web site is a good place to start with when you see mi= croseisms.  You can often see the microseisms from large oceanic storms= at long distances.  East Coast USA hurricanes are very visible on West= Coast USA seismic stations, and are probably also visible in Europe.

Cheers,

Bob Hancock

On 4/11/08 6:46 AM, "ChrisAtUpw@......." <ChrisAtUpw@.......&g= t; wrote:

In a message dated 2008/04/11, gmvoeth@........... writes:

I have noticed a significant increase in the magnitude of such Microseisms<= BR> just hours preceeding a major weather front here in Arizona.
I used to think it might relate to winds hitting the mountains but accordin= g to this it must be wave interaction in the Pacific Ocean.


Hi Geoff,

       Those were probably due to pressu= re noise on the weather front. They can be quite noisy.

       Note that there are several place= s in the ocean which generate microseisms. The news article referreed to onl= y one. The shelving bottom to the west of Norway is another and there are ot= hers in the Pacific.

       Regards,

       Chris Chapman   

Subject: Re: Article On Microseisms From: ChrisAtUpw@....... Date: Fri, 11 Apr 2008 11:06:28 EDT In a message dated 2008/04/11, carpediem1@......... writes: > As you said, microseisms are generated world wide when ocean waves strike > shore. The strength of the microseisms are largely dependent upon the size of > the waves that come ashore. Hi Bob, Not generally I think. There is an ocean area S of Greenland and another on the continental shelf off the NW coast of Norway which dominate the Atlantic systems. You can also get 10 to 12 second stuff from storms directly coming on shore, but that is different. Cold fronts can also have a lot of seismic noise on them, as Geoff observed. Regards, Chris Chapman In a message dated 2008/04/11, carp= ediem1@......... writes:

As you said, microseisms are= generated world wide when ocean waves strike shore.  The strength of t= he microseisms are largely dependent upon the size of the waves that come as= hore.


Hi Bob,

       Not generally I think. There is an ocea= n area S of Greenland and another on the continental shelf off the NW coast=20= of Norway which dominate the Atlantic systems. You can also get 10 to 12 sec= ond stuff from storms directly coming on shore, but that is different.
       Cold fronts can also have a lot of seis= mic noise on them, as Geoff observed.

       Regards,

       Chris Chapman
Subject: Re: Article On Microseisms From: Bob Hancock carpediem1@......... Date: Fri, 11 Apr 2008 09:02:47 -0700 Hi Chris - Cold fronts can generate increased wind velocity. This in turn moves trees and buildings, and this is visible on seismometers; however, this does not appear to travel long distances. This is readily visible on the seismometers located in the Long Valley Caldera, Mammoth Lakes, CA, an area subject to high winds. However, ocean storms, particularly when they come ashore can increase seismic background noise that travels for thousands of kilometers. This is observable when major storms or hurricanes and typhoons occur. In addition, low frequency background seismic noise is more pronounced on seismic stations located on small islands =AD such as Pitcairn Island, Wake Island, and many others all around the world. This is at a much lower frequency than is normally associated with microseisms , and I do not know if would be classified as a microseism. Cheers Bob Hancock =20 On 4/11/08 8:06 AM, "ChrisAtUpw@......." wrote: > In a message dated 2008/04/11, carpediem1@......... writes: >=20 >> As you said, microseisms are generated world wide when ocean waves strik= e >> shore. The strength of the microseisms are largely dependent upon the s= ize >> of the waves that come ashore. >=20 >=20 > Hi Bob, >=20 > Not generally I think. There is an ocean area S of Greenland and > another on the continental shelf off the NW coast of Norway which dominat= e the > Atlantic systems. You can also get 10 to 12 second stuff from storms dire= ctly > coming on shore, but that is different. > Cold fronts can also have a lot of seismic noise on them, as Geoff > observed. >=20 > Regards, >=20 > Chris Chapman Re: Article On Microseisms Hi Ch= ris -

Cold fronts can generate increased wind velocity.  This in turn moves = trees and buildings, and this is visible on seismometers; however, this does= not appear to travel long distances.  This is readily visible on the s= eismometers located in the Long Valley Caldera, Mammoth Lakes, CA, an area s= ubject to high winds.

However, ocean storms, particularly when they come ashore can increase seis= mic background noise that travels for thousands of kilometers.  This is= observable when major storms or hurricanes and typhoons occur.

In addition, low frequency background seismic noise is more pronounced on s= eismic stations located on small islands – such as Pitcairn Island, Wa= ke Island, and many others all around the world.  This is at a much low= er frequency than is normally associated with microseisms , and I do not kno= w if would be classified as a microseism.

Cheers

Bob Hancock

  


On 4/11/08 8:06 AM, "ChrisAtUpw@......." <ChrisAtUpw@.......&g= t; wrote:

In a message dated 2008/04/11, carpediem1@......... writes:

As you said, microseisms are generated world wide when = ocean waves strike shore.  The strength of the microseisms are largely = dependent upon the size of the waves that come ashore.


Hi Bob,

       Not generally I think. There is a= n ocean area S of Greenland and another on the continental shelf off the NW = coast of Norway which dominate the Atlantic systems. You can also get 10 to = 12 second stuff from storms directly coming on shore, but that is different.=
       Cold fronts can also have a lot o= f seismic noise on them, as Geoff observed.

       Regards,

       Chris Chapman   

Subject: Noise From: "Thomas Dick" dickthomas01@............. Date: Sat, 12 Apr 2008 21:45:03 -0500 I have never been satisfied with my setup. I would like some suggestions = on where to look for the noise I still get on my units. Among the things = that I have enjoyed identifying included wind, walnuts falling on the = porch roof, a microwave oven, garbage trucks(empty and full), falling = trees, an assortment of caterpillars and shovels moving dirt and a = seismic truck testing soils in my area for liquifaction. If anybody has = the time, I put a rather large PDF file (~2.5 megs) on this site = http://bachcottage.com/inquiry.pdf. My eventual goal is to get to the = level of the rest of the PSN event submissions. Your suggestions would = be welcomed.
I have never been satisfied with my = setup. I would=20 like some suggestions on where to look for the noise I still get on = my=20 units. Among the things that I have enjoyed identifying included wind, = walnuts=20 falling on the porch roof, a microwave oven, garbage trucks(empty and = full),=20 falling trees, an assortment of caterpillars and shovels moving = dirt and a=20 seismic truck testing soils in my area for liquifaction. If anybody = has the=20 time, I put a rather large PDF file (~2.5 megs) on this site http://bachcottage.com/inquiry.pdf. My eventual goal = is to get=20 to the level of the rest of the PSN event submissions. Your suggestions = would be=20 welcomed.
Subject: Re:Noise From: rsparks rsparks@.......... Date: Sun, 13 Apr 2008 06:26:26 -0700 Hi Dick, I took a look at your posting. Nice job of collecting information and posting. For reference, I collected one hours noise from this morning. http://www.fairpoint.net/~rsparks/080413_090338_ebgz_psn_fft.gif My seismometer is a tilted vertical with a single long spring supporting the sensing coil. The spring is the hinge. I post under the station identifier "EBGZ". The seismometer is in the basement. From looking at your pictures and FFT, I wondered if all of your components are either securely assembled or placed on three point mounts. Four point mounts or components resting on flat surfaces can be unexpected balanced between two semi-stable positions. If so, the microsiems or quakes can move the components between those two positions resulting in high frequency noise. Another source of noise can be the hinges. The AS-1 actually has three hinges if you count the spring attachment points as moving connections. I don't know if lubrication with a light oil would help or not. The problem from hinges is that all hinges have some friction, and the motion in a seismometer hinge starts and stops. Static friction is always greater than moving friction so there is a small "tremble" as the transfer between static and moving occurs. This "tremble" would be recorded as noise. You could test the electronic noise by locking the seismometer. I would not expect much noise from electronics compared to the noise that will come from the seismometer output. Certainly the wind can cause noise but you are probably well aware of the magnitude of wind and other locally generated noise sources. Good luck on your noise hunt. Roger > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Noise > From: "Thomas Dick" > Date: Sat, 12 Apr 2008 21:45:03 -0500 > > > I have never been satisfied with my setup. I would like some suggestions = > on where to look for the noise I still get on my units. Among the things = > that I have enjoyed identifying included wind, walnuts falling on the = > porch roof, a microwave oven, garbage trucks(empty and full), falling = > trees, an assortment of caterpillars and shovels moving dirt and a = > seismic truck testing soils in my area for liquifaction. If anybody has = > the time, I put a rather large PDF file (~2.5 megs) on this site = > http://bachcottage.com/inquiry.pdf. My eventual goal is to get to the = > level of the rest of the PSN event submissions. Your suggestions would = > be welcomed. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re:Noise From: "Thomas Dick" dickthomas01@............. Date: Sun, 13 Apr 2008 12:30:44 -0500 From looking at your pictures and FFT, I wondered if all of your components are either securely assembled or placed on three point mounts Four point mounts or components resting on flat surfaces can be unexpected balanced between two semi-stable positions. I did use four pivot points on the Lehmans...a mistake I won't make again .... the bases for the Lehmans are 1/4" steel these could be used as boat anchors ... unfortunately I sold the boat! The support of the mental plates that hold the magnets isn't as stable ... this could be an issue. But the peaks at 4 hz is gound on the geophone buried outside! If so, the microsiems or quakes can move the components between those two positions resulting in high frequency noise .. The AS-1 uses a knief edge rather than a hinge. The AS-1 sits in an old refrigerator with the door closed. The pivot point on the booms of the Lehmans is a stainless steel ball bearing. The only issue I haven't addressed is that the Lehmans sit on concrete blocks sitting on the concrete floor. From what you infer, this might be an issue. I raised the Lehmans up off the floor so that I didn't have to bend over as much. . I collected one hours noise from this morning. Mine are one minute but it would help know where you two are....??? Georgia??? Macon ...right? You could test the electronic noise by locking the seismometer. I would not expect much noise from electronics compared to the noise that will come from the seismometer output. suggestion under advisement This issue has been around for some time. I even sent one amp board back to Larry for him to look at. I put an isolation transformer and battery back up to help smooth out the AC. I even had the local electric company come out(firends in the right places) with special equipment and test the incoming AC...nothing serious there. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Noise From: "Dale Hardy" photon1@........... Date: Mon, 14 Apr 2008 11:51:52 +1000 Hi Thomas, tried to open the site in IE7 and Firefox unsucessfully, is = the link correct ? thanks Dale ----- Original Message -----=20 From: Thomas Dick=20 To: psn-l@................. Sent: Sunday, April 13, 2008 12:45 PM Subject: Noise I have never been satisfied with my setup. I would like some = suggestions on where to look for the noise I still get on my units. = Among the things that I have enjoyed identifying included wind, walnuts = falling on the porch roof, a microwave oven, garbage trucks(empty and = full), falling trees, an assortment of caterpillars and shovels moving = dirt and a seismic truck testing soils in my area for liquifaction. If = anybody has the time, I put a rather large PDF file (~2.5 megs) on this = site http://bachcottage.com/inquiry.pdf. My eventual goal is to get to = the level of the rest of the PSN event submissions. Your suggestions = would be welcomed.
Hi Thomas, tried to open the site in = IE7 and=20 Firefox unsucessfully, is the link correct ?
thanks
Dale
----- Original Message -----
From:=20 Thomas Dick
Sent: Sunday, April 13, 2008 = 12:45=20 PM
Subject: Noise

I have never been satisfied with my = setup. I=20 would like some suggestions on where to look for the noise I = still get on=20 my units. Among the things that I have enjoyed identifying included = wind,=20 walnuts falling on the porch roof, a microwave oven, garbage = trucks(empty and=20 full), falling trees, an assortment of caterpillars and shovels moving = dirt and a seismic truck testing soils in my area for = liquifaction.=20 If anybody has the time, I put a rather large PDF file (~2.5 megs) on = this=20 site http://bachcottage.com/inquiry.pdf. My eventual = goal is to=20 get to the level of the rest of the PSN event submissions. Your = suggestions=20 would be welcomed.
Subject: Re: Noise From: "Thomas Dick" dickthomas01@............. Date: Sun, 13 Apr 2008 21:15:56 -0500 yes, it might be a little slow particularly in the PDF format....sorry ----- Original Message -----=20 From: Dale Hardy=20 To: psn-l@................. Sent: Sunday, April 13, 2008 8:51 PM Subject: Re: Noise Hi Thomas, tried to open the site in IE7 and Firefox unsucessfully, is = the link correct ? thanks Dale ----- Original Message -----=20 From: Thomas Dick=20 To: psn-l@................. Sent: Sunday, April 13, 2008 12:45 PM Subject: Noise I have never been satisfied with my setup. I would like some = suggestions on where to look for the noise I still get on my units. = Among the things that I have enjoyed identifying included wind, walnuts = falling on the porch roof, a microwave oven, garbage trucks(empty and = full), falling trees, an assortment of caterpillars and shovels moving = dirt and a seismic truck testing soils in my area for liquifaction. If = anybody has the time, I put a rather large PDF file (~2.5 megs) on this = site http://bachcottage.com/inquiry.pdf. My eventual goal is to get to = the level of the rest of the PSN event submissions. Your suggestions = would be welcomed.
yes, it might be a little slow = particularly in the=20 PDF format....sorry
----- Original Message -----
From:=20 Dale Hardy=20
Sent: Sunday, April 13, 2008 = 8:51=20 PM
Subject: Re: Noise

Hi Thomas, tried to open the site in = IE7 and=20 Firefox unsucessfully, is the link correct ?
thanks
Dale
----- Original Message -----
From:=20 Thomas Dick
Sent: Sunday, April 13, 2008 = 12:45=20 PM
Subject: Noise

I have never been satisfied with my = setup. I=20 would like some suggestions on where to look for the noise I = still get=20 on my units. Among the things that I have enjoyed identifying = included wind,=20 walnuts falling on the porch roof, a microwave oven, garbage = trucks(empty=20 and full), falling trees, an assortment of caterpillars and shovels = moving=20 dirt and a seismic truck testing soils in my area for=20 liquifaction. If anybody has the time, I put a rather large PDF file = (~2.5=20 megs) on this site http://bachcottage.com/inquiry.pdf.=20 My eventual goal is to get to the level of the rest of the PSN event = submissions. Your suggestions would be=20 welcomed.
Subject: Re: Noise From: pattilightfoot11@....... Date: Sun, 13 Apr 2008 23:38:55 -0400 Hello, Could you please remove my name from your emailing. I just wanted info if there was anything to be concerned about! Thanks! Patti -----Original Message----- From: Dale Hardy To: psn-l@.............. Sent: Sun, 13 Apr 2008 6:51 pm Subject: Re: Noise Hi Thomas, tried to open the site in IE7 and Firefox unsucessfully, is the link correct ? thanks Dale ----- Original Message ----- From: Thomas Dick To: psn-l@.............. Sent: Sunday, April 13, 2008 12:45 PM Subject: Noise I have never been satisfied with my setup. I would like some suggestions on where to look for?the noise I still get on my units. Among the things that I have enjoyed identifying included wind, walnuts falling on the porch roof, a microwave oven, garbage trucks(empty and full), falling trees, an assortment of caterpillars and shovels moving dirt?and a seismic truck testing soils in?my area for liquifaction. If anybody has the time, I put a rather large PDF file (~2.5 megs) on this site http://bachcottage.com/inquiry.pdf. My eventual goal is to get to the level of the rest of the PSN event submissions. Your suggestions would be welcomed. Hello, Could you please remove my name from your emailing. I just wanted info if there was anything to be concerned about!

Thanks!

Patti



-----Original Message-----
From: Dale Hardy <photon1@...........>
To: psn-l@..............
Sent: Sun, 13 Apr 2008 6:51 pm
Subject: Re: Noise

Hi Thomas, tried to open the site in IE7 and Firefox unsucessfully, is the link correct ?
thanks
Dale
----- Original Message -----
Sent: Sunday, April 13, 2008 12:45 PM
Subject: Noise

I have never been satisfied with my setup. I would like some suggestions on where to look for the noise I still get on my units. Among the things that I have enjoyed identifying included wind, walnuts falling on the porch roof, a microwave oven, garbage trucks(empty and full), falling trees, an assortment of caterpillars and shovels moving dirt and a seismic truck testing soils in my area for liquifaction. If anybody has the time, I put a rather large PDF file (~2.5 megs) on this site http://bachcottage.com/inquiry.pdf. My eventual goal is to get to the level of the rest of the PSN event submissions. Your suggestions would be welcomed.
Subject: Re: Noise From: pattilightfoot11@....... Date: Sun, 13 Apr 2008 23:39:11 -0400 Hello, Could you please remove my name from your emailing. I just wanted info if there was anything to be concerned about! Thanks! Patti -----Original Message----- From: Thomas Dick To: psn-l@.............. Sent: Sun, 13 Apr 2008 7:15 pm Subject: Re: Noise yes, it might be a little slow particularly in the PDF format....sorry ----- Original Message ----- From: Dale Hardy To: psn-l@.............. Sent: Sunday, April 13, 2008 8:51 PM Subject: Re: Noise Hi Thomas, tried to open the site in IE7 and Firefox unsucessfully, is the link correct ? thanks Dale ----- Original Message ----- From: Thomas Dick To: psn-l@.............. Sent: Sunday, April 13, 2008 12:45 PM Subject: Noise I have never been satisfied with my setup. I would like some suggestions on where to look for?the noise I still get on my units. Among the things that I have enjoyed identifying included wind, walnuts falling on the porch roof, a microwave oven, garbage trucks(empty and full), falling trees, an assortment of caterpillars and shovels moving dirt?and a seismic truck testing soils in?my area for liquifaction. If anybody has the time, I put a rather large PDF file (~2.5 megs) on this site http://bachcottage.com/inquiry.pdf. My eventual goal is to get to the level of the rest of the PSN event submissions. Your suggestions would be welcomed. Hello, Could you please remove my name from your emailing. I just wanted info if there was anything to be concerned about!

Thanks!

Patti


-----Original Message-----
From: Thomas Dick <dickthomas01@.............>
To: psn-l@..............
Sent: Sun, 13 Apr 2008 7:15 pm
Subject: Re: Noise

yes, it might be a little slow particularly in the PDF format....sorry
----- Original Message -----
From: Dale Hardy
Sent: Sunday, April 13, 2008 8:51 PM
Subject: Re: Noise

Hi Thomas, tried to open the site in IE7 and Firefox unsucessfully, is the link correct ?
thanks
Dale
----- Original Message -----
Sent: Sunday, April 13, 2008 12:45 PM
Subject: Noise

I have never been satisfied with my setup. I would like some suggestions on where to look for the noise I still get on my units. Among the things that I have enjoyed identifying included wind, walnuts falling on the porch roof, a microwave oven, garbage trucks(empty and full), falling trees, an assortment of caterpillars and shovels moving dirt and a seismic truck testing soils in my area for liquifaction. If anybody has the time, I put a rather large PDF file (~2.5 megs) on this site http://bachcottage.com/inquiry.pdf. My eventual goal is to get to the level of the rest of the PSN event submissions. Your suggestions would be welcomed.
Subject: Re: Noise From: ChrisAtUpw@....... Date: Mon, 14 Apr 2008 00:03:35 EDT In a message dated 2008/04/14, pattilightfoot11@....... writes: > Could you please remove my name from your emailing. Hi Patti, Go to http://psn.quake.net/maillist.html#archives, fill in the form and click the unsubscribe dot. Regards, Chris In a me= ssage dated 2008/04/14, pattilightfoot11@....... writes:

Could you please remove my name= from your emailing.


Hi Patti,

       Go to http://psn.quake.net/maillist.htm= l#archives, fill in the form and click the unsubscribe dot.

       Regards,
      
       Chris
Subject: Oregon earthquake swarm From: jonfr@......... Date: Mon, 14 Apr 2008 21:52:43 -0400 (EDT) Hi all Here are news regarding the Oregon earthquakes. The data so far suggests that there might be an eruption happening in that area. If any of you that are close to this area detect low frequancy signal that is not earthquake you might be looking at eruption tremor that is constant. http://www.sciencedaily.com/releases/2008/04/080413184801.htm http://www.ecanadanow.com/news/science/string-of-strange-earthquakes-rock-oregon-20080414.html Regards. Jón Frímann. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Oregon earthquake swarm From: "Thomas Dick" dickthomas01@............. Date: Mon, 14 Apr 2008 21:19:29 -0500 NBC New tonight on this subject http://www.nbc15online.com/news/national/story.aspx?content_id=5b190a5f-b113-46ac-9f6b-4d8df90f4587 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Oregon earthquake swarm From: "Geoff" gmvoeth@........... Date: Mon, 14 Apr 2008 22:31:46 -0700 I think there are black smokers of volcanic origin in that area and when I was a SONAR tech aboard the USS Bainbridge back in the mid-late 1970s I saw a contact on the TBR (Time Bearing Recorder) that was weak and continuous and was not able to identify that seemed to be coming from that area of the Pacific Ocean. Today it would not surprise me if that contact had been one of those smoker thingys really putting on a show. I pointed the ship right at the contact to try and get closer and louder but the navagational people got upset with me and I turned control back to them so we could all go home. A steady black smoker volcanic thingy would explain the kind of noise I saw but was unable to hear. It was off central Oregon about 280 290 degrees or so as we were headed for the Straights of Juan De Fuca If I remember correctly. The Navagational logs of the ship should have recorded the position and course change of the ship and the ship was pointed by myself directly at the noise source for a few minutes. It was far enough away that the bearing did not change very much as we traveled on and simply lost interest in the target. But also i heard that a Soviet Nuclear Sub liked to do a slow three knot circle in that same area. 100 miles or so off the Coast of Oregon. :-( So you tell me what i saw ??? ----- Original Message ----- From: To: Sent: Monday, April 14, 2008 6:52 PM Subject: Oregon earthquake swarm > Hi all > > Here are news regarding the Oregon earthquakes. The data so far suggests > that there might be an eruption happening in that area. If any of you that > are close to this area detect low frequancy signal that is not earthquake > you might be looking at eruption tremor that is constant. > > http://www.sciencedaily.com/releases/2008/04/080413184801.htm > http://www.ecanadanow.com/news/science/string-of-strange-earthquakes-rock-oregon-20080414.html > > Regards. > Jón Frímann. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Katla volcano preparing eruption From: jonfr@......... Date: Tue, 15 Apr 2008 17:19:40 -0400 (EDT) Hi all It appears that Katla volcano is preparing an eruption. On the 8th April there was a 10 min long tremor detected in the volcano. One of the main glacier rivers from the Myrdalsjokull glacier has been dry since mid January. So the evidence for an coming eruption are mounting. The tremor can be seen here. http://hraun.vedur.is/ja/viku/2008/vika_15/katla.jpg I am going to setup a geophone near Hekla volcano in June, so if there is going to be an eruption in Katla it is going to appear good on that station too. I've post new information on this when I know more. Regards. Jón Frímann. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: quake From: "Thomas Dick" dickthomas01@............. Date: Fri, 18 Apr 2008 04:50:01 -0500 I don't know where but we just had a serious quake here in Evansville = In. Can't get out to some of the networks. It woke me. Lasted for almost = a minute or more. Can anyone tell me where it was?
I don't know where but we just had a = serious quake=20 here in Evansville In. Can't get out to some of the networks. It woke = me. Lasted=20 for almost a minute or more. Can anyone tell me where it = was?
 
Subject: Re: quake From: "Robert Thomasson" rlthomasson@......... Date: Fri, 18 Apr 2008 13:00:25 +0300 It was a magnitude 5.4 about 7 miles from West Salem, Illinois. I picked it up very nicely here in Reno. On Fri, Apr 18, 2008 at 12:50 PM, Thomas Dick wrote: > I don't know where but we just had a serious quake here in Evansville In. > Can't get out to some of the networks. It woke me. Lasted for almost a > minute or more. Can anyone tell me where it was? > > It was a magnitude 5.4 about 7 miles from West Salem, Illinois.  I picked it up very nicely here in Reno.

On Fri, Apr 18, 2008 at 12:50 PM, Thomas Dick <dickthomas01@.............> wrote:
I don't know where but we just had a serious quake here in Evansville In. Can't get out to some of the networks. It woke me. Lasted for almost a minute or more. Can anyone tell me where it was?
 

Subject: Re: quake From: jonfr@......... Date: Fri, 18 Apr 2008 06:05:01 -0400 (EDT) Hi EMSC is reporting Mb5.4 earthquake in Illinois at the depth of 2 km. More details here, http://www.emsc-csem.org/index.php?page=current&sub=detail&id=83987 Regards. Jón Frímann. > It was a magnitude 5.4 about 7 miles from West Salem, Illinois. I picked > it > up very nicely here in Reno. > > On Fri, Apr 18, 2008 at 12:50 PM, Thomas Dick > wrote: > >> I don't know where but we just had a serious quake here in Evansville >> In. >> Can't get out to some of the networks. It woke me. Lasted for almost a >> minute or more. Can anyone tell me where it was? >> >> > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: Mark Robinson mark.robinson@............... Date: Fri, 18 Apr 2008 22:06:29 +1200 Thomas Dick wrote: > > I don't know where but we just had a serious quake here in Evansville > In. Can't get out to some of the networks. It woke me. Lasted for almost > a minute or more. Can anyone tell me where it was? http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008qza6.php 5.4, Illinois -- Mark Robinson ------------- 18 Apr 1906 5am San Francisco devastated by earthquake and ensuing fire. 400 killed. 18 Apr 1954 Nasser becomes Egyptian Premier. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: quake From: "Finke, John" John.Finke@.......... Date: Fri, 18 Apr 2008 05:04:24 -0500 Good thing for the PSN, the EQ woke my whole family and they asked me if = it was an earthquake but I too was unable to get to any networks. Hence rig= ht now, with your response, is the only confirmation we have of it in the Midwest. Earthquake watch.com doesn't even show it. ________________________________ From: psn-l-request@.............. on behalf of Robert Thomasson Sent: Fri 4/18/2008 5:00 AM To: psn-l@.............. Subject: Re: quake It was a magnitude 5.4 about 7 miles from West Salem, Illinois. I picked= it up very nicely here in Reno. On Fri, Apr 18, 2008 at 12:50 PM, Thomas Dick wrote: I don't know where but we just had a serious quake here in Evansville In. Can't get out to some of the networks. It woke me. Lasted for almost = a minute or more. Can anyone tell me where it was? =20 NOTICE - This communication may contain confidential and privileged infor= mation that is for the sole use of the intended recipient. Any viewing, c= opying or distribution of, or reliance on this message by unintended reci= pients is strictly prohibited. If you have received this message in error= , please notify us immediately by replying to the message and deleting it= from your computer. =0A=0A=0A=0A
=0A=
Good thing for= the PSN, the EQ woke my whole family and they asked me if it was an eart= hquake but I too was unable to get to any networks.  Hence right now= , with your response, is the only confirmation we have of it in the Midwe= st.  Earthquake watch.com doesn't even show it.
=0A=

=0A
=0A<= B>From: psn-l-request@.............. on behalf of Robert ThomassonSent: Fri 4/18/2008 5:00 AM
To: psn-l@..............Subject: Re: quake

=0A
It was a magnitude= 5.4 about 7 miles from West Salem, Illinois.  I picked it up very n= icely here in Reno.

=0A
On Fri, Apr 18, 20= 08 at 12:50 PM, Thomas Dick <dickthomas01@.............> wrote:
=0A
=0A
=0A
I don't know where but we just had a serious quake here in Evansvil= le In. Can't get out to some of the networks. It woke me. Lasted for almo= st a minute or more. Can anyone tell me where it was?
=0A 


NOTICE - This communi= cation may contain confidential and privileged information that is for th= e sole use of the intended recipient. Any viewing, copying or distributio= n of, or reliance on this message by unintended recipients is strictly pr= ohibited. If you have received this message in error, please notify us im= mediately by replying to the message and deleting it from your computer.<= /BODY>= Subject: RE: quake From: jonfr@......... Date: Fri, 18 Apr 2008 06:18:12 -0400 (EDT) Hi The earthquake is clearly visable on few plots that are in the U.S. I have a collection of them here, http://www.simnet.is/jonfr500/earthquake/othersten.htm Regards. Jón Frímann. > Good thing for the PSN, the EQ woke my whole family and they asked me if > it > was an earthquake but I too was unable to get to any networks. Hence > right > now, with your response, is the only confirmation we have of it in the > Midwest. Earthquake watch.com doesn't even show it. > > ________________________________ > > From: psn-l-request@.............. on behalf of Robert Thomasson > Sent: Fri 4/18/2008 5:00 AM > To: psn-l@.............. > Subject: Re: quake > > > It was a magnitude 5.4 about 7 miles from West Salem, Illinois. I picked > it > up very nicely here in Reno. > > > On Fri, Apr 18, 2008 at 12:50 PM, Thomas Dick > wrote: > > > I don't know where but we just had a serious quake here in Evansville > In. Can't get out to some of the networks. It woke me. Lasted for almost a > minute or more. Can anyone tell me where it was? > > > > > NOTICE - This communication may contain confidential and privileged > information that is for the sole use of the intended recipient. Any > viewing, copying or distribution of, or reliance on this message by > unintended recipients is strictly prohibited. If you have received this > message in error, please notify us immediately by replying to the message > and deleting it from your computer. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: "Thomas Dick" dickthomas01@............. Date: Fri, 18 Apr 2008 05:54:02 -0500 There are many aftershocks in the area. Quake about 60 (NW) miles away. I am very disappointed at my data -- can't see much. I am sure they will refine data soon. USGS preliminary data seems to be inaccurate. P arrival got here ..05 seconds later than USGS data would indicate. Maybe location (epicenter) is off. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: jonfr@......... Date: Fri, 18 Apr 2008 06:58:09 -0400 (EDT) Hi Low frequency sensors aren't good for local events. You would need something like an 4.5Hz sensor to see this event this close to your location properly. Regards. Jón Frímann. > There are many aftershocks in the area. Quake about 60 (NW) miles away. I > am > very disappointed at my data -- can't see much. I am sure they will refine > data soon. USGS preliminary data seems to be inaccurate. P arrival got > here > .05 seconds later than USGS data would indicate. Maybe location > (epicenter) > is off. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: "Thomas Dick" dickthomas01@............. Date: Fri, 18 Apr 2008 06:16:43 -0500 You're right Jon, the geophone displays are better but still amplitudes make it almost impossible to see much -- distortion. .. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: jonfr@......... Date: Fri, 18 Apr 2008 07:31:57 -0400 (EDT) Hi I have my geophone on high amplitude. I haven't noticed any distortion. Noise I see, but no distortion. The biggest earthquake I have recored was a M4.3 at the distance of 85 km, no issues with that recording at all. Regards. Jón Frímann. > You're right Jon, the geophone displays are better but still amplitudes > make > it almost impossible to see much -- distortion. > . > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: "Thomas Dick" dickthomas01@............. Date: Fri, 18 Apr 2008 08:37:52 -0500 I see they downgraded the quake to 5.2. I describe it as a "serious" quake in my first posting. I suppose I based this on passed quakes in this locality which did not last as long. Certainly this lasted a lot longer. This one lasted at least 45 seconds e.g. felt for that long. We have lights on our desks that are suspended. The quake waves continued to vibrate for over two minutes. I used the word distortion of data. This quake was so strong and so close. If this were audio, I would describe the incoming data as being clipped. I saved six aftershocks out of maybe ten or more I considered significant. At least two were felt and reported by TV listeners as I watched my computer screen. Lehmans and AS-1 showed tendency toward peak in the .1 to .3 Hz range five minutes before quake on a relatively quiet display. And below .1 Hz just seconds before quake. Is that important? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: jonfr@......... Date: Fri, 18 Apr 2008 11:40:45 -0400 (EDT) Hi all There just was an aftershock now, emsc says it is M 4.5. See here, http://www.emsc-csem.org/index.php?page=current&sub=detail&id=84013 (might be outdated soon) By the looks of it, there is a slight chance of a swarm of mag 4.0 to 5.5 earthquakes, they might even go as high as mag 6.0. But that would be a rare event, but I am not expecting it. I however also don't rule it out. Regards. Jón Frímann. > I see they downgraded the quake to 5.2. I describe it as a "serious" quake > in my first posting. I suppose I based this on passed quakes in this > locality which did not last as long. Certainly this lasted a lot longer. > This one lasted at least 45 seconds e.g. felt for that long. We have > lights > on our desks that are suspended. The quake waves continued to vibrate for > over two minutes. I used the word distortion of data. This quake was so > strong and so close. If this were audio, I would describe the incoming > data > as being clipped. I saved six aftershocks out of maybe ten or more I > considered significant. At least two were felt and reported by TV > listeners > as I watched my computer screen. Lehmans and AS-1 showed tendency toward > peak in the .1 to .3 Hz range five minutes before quake on a relatively > quiet display. And below .1 Hz just seconds before quake. Is that > important? > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: "Thomas Dick" dickthomas01@............. Date: Fri, 18 Apr 2008 11:08:38 -0500 > There just was an aftershock now, emsc says it is M 4.5. See here, > http://www.emsc-csem.org/index.php?page=current&sub=detail&id=84013 (might > be outdated soon) > >Here in Indiana, before this last quake the FFT for 20 seconds just before >dropped to below one from over 10 before the first quake in the frequencies >of .06 to .3 Hz __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: Pete Rowe ptrowe@......... Date: Fri, 18 Apr 2008 10:21:08 -0700 (PDT) Loud and clear in San Jose, CA. It's on my website right now (www(dot)rowelabs(dot)com Enjoy Pete --- On Fri, 4/18/08, Thomas Dick wrote: > From: Thomas Dick > Subject: Re: quake > To: psn-l@.............. > Date: Friday, April 18, 2008, 9:08 AM > > There just was an aftershock now, emsc says it is M > 4.5. See here, > > > http://www.emsc-csem.org/index.php?page=current&sub=detail&id=84013 > (might > > be outdated soon) > > > >Here in Indiana, before this last quake the FFT for 20 > seconds just before > >dropped to below one from over 10 before the first > quake in the frequencies > >of .06 to .3 Hz > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more > information. ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: shammon1@............. Date: Fri, 18 Apr 2008 11:34:01 -0700 (GMT-07:00) Wow after looking at your site Pete I went and checked my long period AT1 in Aptos and can see I also recorded that event... (and I thought my system was not working that well.) I'm at Cabrillo College teaching a Social Justice Research class at the moment but when I get home I'll check and upload my data. I bet that Jan and Larry also recorded these events. Steve Hammond PSN San Jose, Aptos, CA http://pw2.netcom.com/~shammon1/recent.htm >Loud and clear in San Jose, CA. >It's on my website right now (www(dot)rowelabs(dot)com >Enjoy >Pete --- On Fri, 4/18/08, Thomas Dick wrote: > From: Thomas Dick > Subject: Re: quake > To: psn-l@.............. > Date: Friday, April 18, 2008, 9:08 AM > > There just was an aftershock now, emsc says it is M > 4.5. See here, > > > http://www.emsc-csem.org/index.php?page=current&sub=detail&id=84013 > (might > > be outdated soon) > > > >Here in Indiana, before this last quake the FFT for 20 > seconds just before > >dropped to below one from over 10 before the first > quake in the frequencies > >of .06 to .3 Hz > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more > information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Winquake From: "Thomas Dick" dickthomas01@............. Date: Sun, 20 Apr 2008 08:06:29 -0500 An unusual problem that I am sure those of you in California have = solved. These southern Illinois quakes that are over about a Magnitude = of 3 and less than fourty miles away appear to overloaded my system = causing clipping at peaks. Is there an adjustment within Windquake I = have missed?
An unusual problem that I am sure those = of you in=20 California have solved. These southern Illinois quakes that are over = about a=20 Magnitude of 3 and less than fourty miles away appear to overloaded my = system=20 causing clipping at peaks. Is there an adjustment within Windquake I = have=20 missed?
Subject: Re: Winquake From: "Geoff" gmvoeth@........... Date: Sun, 20 Apr 2008 07:48:46 -0700 I think you need what is called a log amplifier that had the gain characteristics of a PN junction knee ( from a curve tracer ) The gain decreases as the voltage increases. Then you can get both big and small without clipping but still that means you are seeing a distorted signal. Otherwise you need several channel in decades ( two or three ) then you can pick the largest signal that is not clipped. It is usually a hardware issue and not a software unless you are setting gain via shifting of A/D gain resolution(looking at top 8 bits instead of 12 ). ----- Original Message ----- From: "Thomas Dick" To: Sent: Sunday, April 20, 2008 6:06 AM Subject: Winquake An unusual problem that I am sure those of you in California have solved. These southern Illinois quakes that are over about a Magnitude of 3 and less than fourty miles away appear to overloaded my system causing clipping at peaks. Is there an adjustment within Windquake I have missed? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Winquake From: Pete Rowe ptrowe@......... Date: Sun, 20 Apr 2008 17:26:27 -0700 (PDT) Hi The problem with clipping is in the amplifiers ahead of the A/D. You can run the overall gain down a little and see if that helps. You would really like to know which stage is clipping and then adjust the gain until it doesn't. Ideally you would put a very small sine wave signal (1 Hz?) into the input of the amplifier chain in place of the coil. Then run the input level up until you get clipping at the A/D. Then, with an oscilloscope, trace through all of your stages to see where the clipping is occurring. You may want to re-distribute the gain or just reduce it to where you are happy with the way it performs on local quakes. I have many earthquakes in the less than magnitude 3 range (maybe 30 a month)and my A/D isn't anywhere near saturation. Yet, I can see a 7.0 anywhere on earth. Good luck and let us all know how you are progressing. Regards, Pete --- On Sun, 4/20/08, Thomas Dick wrote: > From: Thomas Dick > Subject: Winquake > To: psn-l@.............. > Date: Sunday, April 20, 2008, 6:06 AM > An unusual problem that I am sure those of you in California > have solved. These southern Illinois quakes that are over > about a Magnitude of 3 and less than fourty miles away > appear to overloaded my system causing clipping at peaks. > Is there an adjustment within Windquake I have missed? ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: quake From: Pete Rowe ptrowe@......... Date: Mon, 21 Apr 2008 12:40:38 -0700 (PDT) Hi Steve It's nice to know that you are still running your seismometer. The computer I'm using keeps crashing so I need a new XP machine. I just haven't gotten around to buying one. Regards, Pete --- On Fri, 4/18/08, shammon1@............. wrote: > From: shammon1@............. > Subject: Re: quake > To: psn-l@.............. > Date: Friday, April 18, 2008, 11:34 AM > Wow after looking at your site Pete I went and checked my > long period AT1 in Aptos and can see I also recorded that > event... (and I thought my system was not working that > well.) I'm at Cabrillo College teaching a Social > Justice Research class at the moment but when I get home > I'll check and upload my data. I bet that Jan and Larry > also recorded these events. > Steve Hammond PSN San Jose, Aptos, CA > > http://pw2.netcom.com/~shammon1/recent.htm > > > >Loud and clear in San Jose, CA. > >It's on my website right now > (www(dot)rowelabs(dot)com > >Enjoy > >Pete > > > --- On Fri, 4/18/08, Thomas Dick > wrote: > > > From: Thomas Dick > > Subject: Re: quake > > To: psn-l@.............. > > Date: Friday, April 18, 2008, 9:08 AM > > > There just was an aftershock now, emsc says it is > M > > 4.5. See here, > > > > > > http://www.emsc-csem.org/index.php?page=current&sub=detail&id=84013 > > (might > > > be outdated soon) > > > > > >Here in Indiana, before this last quake the FFT > for 20 > > seconds just before > > >dropped to below one from over 10 before the first > > quake in the frequencies > > >of .06 to .3 Hz > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. > with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more > > information. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more > information. ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: dueling earthquakes From: "Thomas Dick" dickthomas01@............. Date: Fri, 25 Apr 2008 12:54:29 -0500 Illinois and Nevada are in competitions -- I felt this one in southern = Indiana -- now its Nevada's turn
Illinois and Nevada are in competitions = -- I felt=20 this one in southern Indiana -- now its Nevada's = turn
Subject: Earthquake deteced near Greenland From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 25 Apr 2008 20:45:10 +0000 Hi all This morning my sensor did detect an earthquake near coast of Greenland. IMO says it is ML3.2, but given the distance from there sensors this is problay an underestimate of it's size. I would guess that it's size was around ML4.0 to ML4.4. It did appear nicely on my system, I will post it when I have final size and location on it. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: nevada earthqukaes From: jonfr@......... Date: Mon, 28 Apr 2008 16:43:41 -0400 (EDT) Hi all I've been looking at distribution of the Nevada earthquakes that have been happening over the past few weeks. Given the time space and the how dense the earthquake have been happening. I agree with the seismologist that have been saying the news that there is a good chance of big earthquake in that area. I would estimate that this big earthquake is 1 week to 5 weeks away from happening. If nothing special happens between now and then. The size estimate is from 6.5 to 7.5. For those of you that are close by this area. I would suggest that you keep a close on the micro earthquakes in the area. As the events now are pre-earthquakes before the big one hits. The intal earthquake before the big one might be a mag 5.5 earthquake, given it's current behavior. Regards. Jón Frímann. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: dueling earthquakes From: "Paul Cianciolo" Paulc@........ Date: Mon, 28 Apr 2008 17:16:43 -0400 Tom, Where to after Nevada? Paul -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of Thomas Dick Sent: Friday, April 25, 2008 1:54 PM To: psn-l@.............. Subject: dueling earthquakes Illinois and Nevada are in competitions -- I felt this one in southern Indiana -- now its Nevada's turn
Tom,
 
Where to after=20 Nevada?
 
Paul
-----Original Message-----
From: = psn-l-request@................. [mailto:psn-l-request@...............On Behalf Of Thomas=20 Dick
Sent: Friday, April 25, 2008 1:54 PM
To:=20 psn-l@..............
Subject: dueling=20 earthquakes

Illinois and Nevada are in = competitions -- I felt=20 this one in southern Indiana -- now its Nevada's=20 turn
Subject: RE: dueling earthquakes From: "Kareem, Heyjoojoo.Com" system98765@............. Date: Mon, 28 Apr 2008 17:50:18 -0700 I've been watching that area too (from California). It has been very interesting. To bring a "possible" California similarity into this, there have been similar patterns within the San Francisco Bay Area. Yes, we have had quake swarms all over the bay area, particularly in one area in what's known as the East Bay (Concord, Alamo area). The swarm lasted for a few weeks with the largest reaching 4.5 and then the activity abruptly stopped. But the swarms in Nevada do seem to reflect the dueling quake activity that occurred in our area during the 1800's (I wasn't here then) when there was a M6 quake in the east bay, followed years later by M7 quake in the Santa Cruz Mtns area (Loma Prieta area), only to be later followed by a M7 back in the east bay. It was sort of a battle of the bay - east bay vs. south bay. The area spans about 150 - 200 miles. I've been watching the depth of many of the quakes and most of them seem to be in the 0-7km range but there is the consistent number of events occurring deeper, in the 10-18km range too. Those deeper events might be more indicative of something maybe unusually large. Any comments? _____ From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Paul Cianciolo Sent: Monday, April 28, 2008 2:17 PM To: psn-l@.............. Subject: RE: dueling earthquakes Tom, Where to after Nevada? Paul -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of Thomas Dick Sent: Friday, April 25, 2008 1:54 PM To: psn-l@.............. Subject: dueling earthquakes Illinois and Nevada are in competitions -- I felt this one in southern Indiana -- now its Nevada's turn
I've been watching that area too (from = California). It has=20 been very interesting. To bring a "possible" California similarity into = this,=20 there have been similar patterns within the San Francisco Bay Area. Yes, = we have=20 had quake swarms all over the bay area, particularly in one area in = what's known=20 as the East Bay (Concord, Alamo area). The swarm lasted for a = few=20 weeks with the largest reaching 4.5 and then the activity abruptly = stopped.=20 But the swarms in Nevada do seem to reflect the dueling quake = activity that=20 occurred in our area during the 1800's (I wasn't here then) when there = was a M6=20 quake in the east bay, followed years later by M7 quake in the Santa = Cruz Mtns=20 area (Loma Prieta area), only to be later followed by a M7 back in the = east bay.=20 It was sort of a battle of the bay - east bay vs. south = bay. The area=20 spans about 150 - 200 miles.
 
I've been watching the depth of many of the = quakes and most=20 of them seem to be in the 0-7km range but there is the consistent number = of=20 events occurring deeper, in the 10-18km range too. Those deeper events = might be=20 more indicative of something maybe unusually large.
 
Any comments?
 


From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of Paul=20 Cianciolo
Sent: Monday, April 28, 2008 2:17 PM
To:=20 psn-l@..............
Subject: RE: dueling=20 earthquakes

Tom,
 
Where to after=20 Nevada?
 
Paul
-----Original Message-----
From: = psn-l-request@................. [mailto:psn-l-request@...............On Behalf Of Thomas=20 Dick
Sent: Friday, April 25, 2008 1:54 PM
To:=20 psn-l@..............
Subject: dueling=20 earthquakes

Illinois and Nevada are in = competitions -- I felt=20 this one in southern Indiana -- now its Nevada's=20 turn
Subject: Meteoroid ? From: jonfr@......... Date: Tue, 29 Apr 2008 08:38:14 -0400 (EDT) Hi all I was speaking to an seismologist at IMO about the "earthquake" that happen the 25th April around 07:40. He did suggest that it was a Meteoroid rather then a earthquake, as the event was recored on most seismic stations in Iceland around the same time. He did suggests that this was an earthquake, but given the clues it seems unlikely. If this was a meteoroid, it is mostly likely that it did exploit high up in the atmosphere. But no explosion has been reported so far, but the area where this most likely did happen is unpopulated for most part. This was closer to Greenland then Iceland, it appears. I did also record this event and the trace can be seen here. http://seismicnet.com/cgi-dos/makegif.exe?/quakes/0804/080425.073900.hvtz.psn http://seismicnet.com/cgi-dos/makegif.exe?/quakes/0804/080425.073900.hvtn.psn http://seismicnet.com/cgi-dos/makegif.exe?/quakes/0804/080425.073900.hvte.psn This is a filtered trace at 2Hz (I think, don't remember what I did filter it on). It would be nice to get a different opinion on this. Regards. Jón Frímann. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: dueling earthquakes From: "Thomas Dick" dickthomas01@............. Date: Tue, 29 Apr 2008 11:41:05 -0500 I don't think either Nevada or Southern Illinois is done yet. We are = still getting aftershocks and so is Nevada,
 
I don't think either Nevada or Southern Illinois = is done=20 yet. We are still getting aftershocks and so is=20 Nevada,
Subject: Re: dueling earthquakes From: "Thomas Dick" dickthomas01@............. Date: Tue, 29 Apr 2008 12:15:08 -0500 To bring a "possible" California similarity into this, there have been similar patterns within the San Francisco Bay Area. Yes, we have had quake swarms all over the bay area, particularly in one area in what's known as the East Bay (Concord, Alamo area). The swarm lasted for a few weeks with the largest reaching 4.5 and then the activity abruptly stopped. National TV News a few weeks ago suggested a major quake out there was to be expected. I think that thinking was stimulated by the recent quake activity in the Alaskan chain and down in South America.. But the swarms in Nevada do seem to reflect the dueling quake activity that occurred in our area during the 1800's (I wasn't here then) when there was a M6 quake in the east bay, followed years later by M7 quake in the Santa Cruz Mtns area (Loma Prieta area), only to be later followed by a M7 back in the east bay. It was sort of a battle of the bay - east bay vs. south bay. The area spans about 150 - 200 miles. The area out there is so complex. I've been watching the depth of many of the quakes and most of them seem to be in the 0-7km range but there is the consistent number of events occurring deeper, in the 10-18km range too. Those deeper events might be more indicative of something maybe unusually large. Any comments? Quakes in southern Illinois are deep because most of the faults are very old. One "felt" quake in 20 years is the norm. Most quakes the do not last long -- maybe less than 20 seconds --several of these recent quakes went on for over twice that time frame ....and usually are not centered in one area like this sequence. The sediments are also deep -- as much as 300 ft in many areas. This means they are felt! The shaking extends out. The news didn't really cover the aftereffects because there were no human injuries. I talked to an acquaintence living in the six mile diameter area of these quakes. He is a farmer. His home and outbuildings did just fine. But his mother's home was seriously damaged and he didn't know if it was worth fixing. And there are others in that area too. I expect things to quiet down here but Nevada and west coast may not be done. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Meteoroid ? From: "Geoff" gmvoeth@........... Date: Tue, 29 Apr 2008 10:56:03 -0700 I find it odd that an air explosion would cause a ground trace of that nature. Maybe someone can tell us what past air explosions have looked like. I would expect a meteor impact to look like a mine blast giving upward motion at first arrival all around the impact point. As for an air explosion would you see both P and s waves since air is a fluid and propagates no such S waves unless they form on contact with the Earth. Anyone have examples of air blast seismic signatures ? ----- Original Message ----- From: To: Sent: Tuesday, April 29, 2008 5:38 AM Subject: Meteoroid ? > Hi all > > I was speaking to an seismologist at IMO about the "earthquake" that > happen the 25th April around 07:40. He did suggest that it was a Meteoroid > rather then a earthquake, as the event was recored on most seismic > stations in Iceland around the same time. He did suggests that this was an > earthquake, but given the clues it seems unlikely. If this was a > meteoroid, it is mostly likely that it did exploit high up in the > atmosphere. But no explosion has been reported so far, but the area where > this most likely did happen is unpopulated for most part. This was closer > to Greenland then Iceland, it appears. > > I did also record this event and the trace can be seen here. > > http://seismicnet.com/cgi-dos/makegif.exe?/quakes/0804/080425.073900.hvtz.psn > http://seismicnet.com/cgi-dos/makegif.exe?/quakes/0804/080425.073900.hvtn.psn > http://seismicnet.com/cgi-dos/makegif.exe?/quakes/0804/080425.073900.hvte.psn > > This is a filtered trace at 2Hz (I think, don't remember what I did filter > it on). > > It would be nice to get a different opinion on this. > > Regards. > Jón Frímann. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: NZ tsunami warning network goes live From: Mark Robinson mark.robinson@............... Date: Wed, 30 Apr 2008 13:20:29 +1200 http://wildland.owdjim.gen.nz/?p=604 http://www.geonet.org.nz/tsunami/gauges/index.html http://www.geonet.org.nz/docs/tsunami/tsunami-brochure.pdf -- regards Mark Robinson ------------- 30 Apr 1991 A Cyclone hits Bangladesh killing over 125,000 people. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: A Historical magnet assembly for either eddy current dampening, or induction coil pickup From: "meredith lamb" paleoartifact@......... Date: Fri, 2 May 2008 13:29:36 -0600 Hi all, The below is a reference to a web page with pictures I put up, where; a older magnet and iron assembly does essentially the same tasks as earlier outlined in many past PSN emails by Chris Chapman. http://seismometer.googlepages.com/magnetpu%26d This old assembly could essentially be used obviously for either eddy current dampening and copper coil induction pickups in a seismometer. A main point with using such in a home brew seismometer, is that with the current availability of strong field neodymium magnets in a wide span of sizes; its relatively easy to fashion ones own unit; rather than use a simple two pole (usually) alnico magnet, with a far weaker magnetic field. Meredith Lamb Hi all,

The below is a reference to a web page with pictures I put up, where; a older magnet and iron assembly
does essentially the same tasks as earlier outlined in many past PSN emails by Chris Chapman. 

http://seismometer.googlepages.com/magnetpu%26d

This old assembly could essentially be used obviously for either eddy current dampening and copper
coil induction pickups in a seismometer. 

A main point with using such in a home brew seismometer, is that with the current availability of
strong field neodymium magnets in a wide span of sizes; its relatively easy to fashion ones own
unit; rather than use a simple two pole (usually) alnico magnet, with a far weaker magnetic field.

Meredith Lamb

 
Subject: Large eruption in Chile From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sat, 03 May 2008 19:30:59 +0000 Hi all There is a large eruption in Chile, the ash plume has reached 16 km yesterday when the eruption did start. The current information that I have is limited, but this is what I got on the volcano postlist yesterday. -------- Chait=E9n Southern Chile 42.833S, 72.646W; summit elev. 1,122 m All times are local (=3D UTC - 4 hours) Later updates from multiple sources have indicated that the 2 May 2008 eruption at Minchinm=E1vida (Vnum 1508-04) was incorrectly attributed. The volcano that erupted was an adjacent caldera, Chaiten (1508-041). A Volcanic Ash Advisory stated that ash rose to altitudes in the range of 45,000-55,000 feet [13.7-16.7 km]. Chaiten lies slightly to the W of Minchinmavida. Chaiten volcano lacks any known modern eruptions but a radiocarbon date on its tephra (CHA1) yields a date of 7,430 BC (plus or minus 75 years). Since my message this morning much news (in Spanish and English) has emerged about today's eruption at Chaiten, correcting the earlier confusion regarding the name and including numerous photos of impressive plumes. One report said 1,500 people were evacuated in Chile. What follows after the Geologic Summary are relevant portions of reports by others. My thanks to this listserve's Kimberly Genareau and these other contributors. Geologic Summary. Chait=E9n is a small, glacier-free late-Pleistocene caldera with a Holocene lava dome located 10 km NE of the town of Chait=E9n on the Gulf of Corcovado. The north side of the rhyolitic, 962-m-high obsidian lava dome occupying the 3.5-km-wide caldera is unvegetated. Obsidian cobbles from this dome found in the Blanco River are the source of prehistorical artifacts from archaeological sites along the Pacific coast as far as 400 km away from the volcano to the north and south. The caldera is breached on the SW side by a river that drains to the bay of Chait=E9n, and the high point on its southern rim reaches 1,122 m. Two small lakes occupy the caldera floor on the west and north sides of the lava dome. Moreno (1985 pers. comm.) noted that the nearby volcano of Yelcho listed by the International Association of Volcanology and Chemistry of the Earth's Interior (1973) does not exist. --------- Also, given the pictures that I have seen on the news. It can be save to assume that this eruption is not small. News here, http://afp.google.com/article/ALeqM5iTRpKWeEuLPkSc23OYxUGssHV3iA More news here, http://news.google.com/news?ned=3Dus&hl=3Den&ned=3Dus&q=3DChaiten&btnG=3DSe= arch +News This volcano last erupted in 7420 BC =B1 75 years. So it has lied dormant for a long time now. More information on the volcano here, http://www.volcano.si.edu/world/volcano.cfm?vnum=3D1508-041 If this is a really big eruption, it might create issues for the nearby countries. At least part of the south part of the planet. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Sun, 4 May 2008 21:17:52 -0700 Hello PSN Peoples; I am trying to make a routine that will save an array of single bytes to a raw data file on the hard drive and do this as quickly as possible. Below you will see a routine that works very well for me but its too darn slow. When the program enters this routine it will linger for many seconds appearently converting the data array into the strings before eventually actually saving the data into the file. I do not understand the terrible long time this routine seems to take. Can someone with more experience please tell me what Im doing wrong that takes so long ( literally several seconds for only 32770 bytes total) to complete. I would like a speed that rivals a BSAVE command. This is how i save my seismic data to a raw 8 bit file after recording it to the array in RAM. Thanks for any help. feel free ro email me direct. Regards; geoff ********************************** POWERBASIC FOR DOS COMPILER SOURCE CODE $LIB COM ON $LIB FULLFLOAT ON $LIB VGA ON $ERROR BOUNDS ON $ERROR NUMERIC ON $ERROR OVERFLOW ON $ERROR STACK ON $CPU 80386 $COM 1024 $STRING 32 $STACK 2048 $SOUND 256 $DYNAMIC $COMPILE EXE "TEST.EXE" $FLOAT NPX $OPTIMIZE SPEED $EVENT $OPTION CNTLBREAK ON ' CREATE AN ARRAY FOR RAW DATA DIM VIRTUAL DATA_1?(0:32780) ' Fill the array with ascii text characters ' So resulting file can be easily examined ' with a hex editor normally this is the recording FOR a = 0 to 32780 : DATA_1?(a) = ( 65 + a MOD 58 ) : NEXT a ' Form a file path and name FILE1$ = "c:\data\test.dat" ' screen not necessary just habit SCREEN 11 ' below is the routine in question tmpz1$ = "" FOR ka = 0 to 32255 tmpz1$ = tmpz1$ + chr$(DATA_1?(ka)) NEXT ka tmpz2$ = "" FOR ka = 32256 to 32769 tmpz2$ = tmpz2$ + chr$(DATA_1?(ka)) NEXT ka OPEN FILE1$ FOR BINARY AS #1 SEEK #1,0 : PUT$ #1,tmpz1$ SEEK #1,32256 : PUT$ #1,tmpz2$ CLOSE #1 tmpz1$ = "" : tmpz2$ = "" ' task completed return to system SYSTEM ***************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: Mark Robinson mark.robinson@............... Date: Mon, 05 May 2008 17:21:45 +1200 Geoff wrote: > Hello PSN Peoples; > > I am trying to make a routine > that will save an array of single > bytes to a raw data file on the hard > drive and do this as quickly as possible. > Below you will see a routine that works > very well for me but its too darn slow. > When the program enters this routine > it will linger for many seconds > appearently converting the data array > into the strings before eventually > actually saving the data into the file. > I do not understand the terrible long > time this routine seems to take. > > Can someone with more experience > please tell me what Im doing wrong > that takes so long ( literally several > seconds for only 32770 bytes total) to complete. > I would like a speed that rivals a BSAVE command. Your first mistake is using Basic. This will be between 10 and 1000 times slower than a compiled language. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Sun, 4 May 2008 23:09:26 -0700 You are speaking from an ignorant view point. Just Like Me :-) If you study programming languages you will find Power Basic one of the best BASIC Compilers out there for MSDOS machines. I hate C++ and really like BASIC and FORTRAN and ASSEMBLY if the computer world had concentrated on developing BASIC there would be nothing today that would compare since BASIC was the laymans Tool. We need standards so that everyone can do whatever without the Tower of Babel messing things up. Assembly is by far the best for speed but try getting your hands on register maps for all the hardwares out there. I hope Im Wrong The Flavor of Your response here is just like those Counter Intelligent News peoples that are ubiquitous on the news servers. Im hoping you are a kid and not an adult. Like I said you are somewhat ignorant like me :-) Best Regards; geoff ----- Original Message ----- From: "Mark Robinson" To: Sent: Sunday, May 04, 2008 10:21 PM Subject: Re: Basic Programming Help desired? > Geoff wrote: >> Hello PSN Peoples; >> >> I am trying to make a routine >> that will save an array of single >> bytes to a raw data file on the hard >> drive and do this as quickly as possible. >> Below you will see a routine that works >> very well for me but its too darn slow. >> When the program enters this routine >> it will linger for many seconds >> appearently converting the data array >> into the strings before eventually >> actually saving the data into the file. >> I do not understand the terrible long >> time this routine seems to take. >> >> Can someone with more experience >> please tell me what Im doing wrong >> that takes so long ( literally several >> seconds for only 32770 bytes total) to complete. >> I would like a speed that rivals a BSAVE command. > > Your first mistake is using Basic. > > This will be between 10 and 1000 times slower than a compiled language. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Basic Programming Help desired? From: "Timothy Carpenter" geodynamics@....... Date: Mon, 5 May 2008 10:40:15 -0400 Geoff, My experience is with the various versions of MS Basic, not Powerbasic. However, the following comments may help. Check the effects of the various compiler directives on the speed of the routine. In particular, check the effects of the various error handlers. Turning them off may increase the speed. I think your biggest hangup is creating a long string from your raw data -- that's a huge amount of unnecessary conversions. Instead, you should consider creating a binary file () and then writing (stream) the individual bytes to the file as soon as you receive them from the AD card. Here's a link to a routine that may give you some guidance: http://www.vb-helper.com/howto_read_write_binary_file.html Also, check the utilities and tools that may have accompanied your AD card. Often the manufacturer will supply tools and/or examples that allow you to stream data directly from the card to disk. Check their website too. Some (most?) versions of Basic are intrinsically slow because they are not truly compiled in the way FORTRAN would be. In your case it probably isn't necessary, but if you really need the speed, then you should consider some other language besides Basic -- e.g., C (C++), Fortran and ultimately, Assembly. Regards, -Tim- -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Geoff Sent: Monday, May 05, 2008 12:18 AM To: PSN Subject: Basic Programming Help desired? Hello PSN Peoples; I am trying to make a routine that will save an array of single bytes to a raw data file on the hard drive and do this as quickly as possible. Below you will see a routine that works very well for me but its too darn slow. When the program enters this routine it will linger for many seconds appearently converting the data array into the strings before eventually actually saving the data into the file. I do not understand the terrible long time this routine seems to take. Can someone with more experience please tell me what Im doing wrong that takes so long ( literally several seconds for only 32770 bytes total) to complete. I would like a speed that rivals a BSAVE command. This is how i save my seismic data to a raw 8 bit file after recording it to the array in RAM. Thanks for any help. feel free ro email me direct. Regards; geoff ********************************** POWERBASIC FOR DOS COMPILER SOURCE CODE $LIB COM ON $LIB FULLFLOAT ON $LIB VGA ON $ERROR BOUNDS ON $ERROR NUMERIC ON $ERROR OVERFLOW ON $ERROR STACK ON $CPU 80386 $COM 1024 $STRING 32 $STACK 2048 $SOUND 256 $DYNAMIC $COMPILE EXE "TEST.EXE" $FLOAT NPX $OPTIMIZE SPEED $EVENT $OPTION CNTLBREAK ON ' CREATE AN ARRAY FOR RAW DATA DIM VIRTUAL DATA_1?(0:32780) ' Fill the array with ascii text characters ' So resulting file can be easily examined ' with a hex editor normally this is the recording FOR a = 0 to 32780 : DATA_1?(a) = ( 65 + a MOD 58 ) : NEXT a ' Form a file path and name FILE1$ = "c:\data\test.dat" ' screen not necessary just habit SCREEN 11 ' below is the routine in question tmpz1$ = "" FOR ka = 0 to 32255 tmpz1$ = tmpz1$ + chr$(DATA_1?(ka)) NEXT ka tmpz2$ = "" FOR ka = 32256 to 32769 tmpz2$ = tmpz2$ + chr$(DATA_1?(ka)) NEXT ka OPEN FILE1$ FOR BINARY AS #1 SEEK #1,0 : PUT$ #1,tmpz1$ SEEK #1,32256 : PUT$ #1,tmpz2$ CLOSE #1 tmpz1$ = "" : tmpz2$ = "" ' task completed return to system SYSTEM ***************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Mon, 5 May 2008 09:15:29 -0700 THANK you but this is not the problem I am addressing. A/D is not the concern at this time. ALL data is saved to an array that resides somewhere in MSDOS EMS RAM. What I am trying to do is save that array as fast as possible FROM RAM to a file residing on hard disk. This lets me turn off the disk while the recorder is running and turn on the drive only for file operations ( permanent storage ). I have always had troubles quickly dealing with file formation and lots of bytes. If you play with BSAVE command you will find it is almost instant unlike my own programs. If only I could make a program as fast as BSAVE BASIC command then I could do anything I need to in this regard very quickly and miss few samples inbetween recordings. Immediately below is the routine which does this operation as fast as I have ever done it. Comments are welcome. Regards; geoff ************************* $LIB COM ON $LIB FULLFLOAT ON $LIB VGA ON $ERROR BOUNDS ON $ERROR NUMERIC ON $ERROR OVERFLOW ON $ERROR STACK ON $CPU 80386 $COM 1024 $STRING 32 $STACK 2048 $SOUND 256 $DYNAMIC $COMPILE EXE "TEST.EXE" $FLOAT NPX $OPTIMIZE SPEED $EVENT $OPTION CNTLBREAK ON DIM VIRTUAL DATA_1?(0:32780) ' Create a test set of data FOR a = 0 to 32780 : DATA_1?(a) = ( 65 + a MOD 58 ) : NEXT a ' Create the path and filename FILE1$ = "c:\data\test.dat" ' Write The Array in EMS RAM To The File on HARD Drive CLS PRINT "NOW SAVING DATA TO FILE c:\data\test.dat " OPEN FILE1$ FOR BINARY AS #1 FOR ka = 0 to 7 tmpz1$ = "" For kb = 0 to 4095 kc = (( ka * 4096 ) + kb ) tmpz1$ = tmpz1$ + chr$(DATA_1?(kc)) NEXT kb kd = ( ka * 4096 ) SEEK #1,kd : PUT$ #1,tmpz1$ NEXT ka tmpz1$ = "" FOR ka = 32256 to 32769 tmpz1$ = tmpz1$ + chr$(DATA_1?(ka)) NEXT ka SEEK #1,32256 : PUT$ #1,tmpz1$ CLOSE #1 tmpz1$ = "" END ********* ----- Original Message ----- From: "Timothy Carpenter" To: Sent: Monday, May 05, 2008 7:40 AM Subject: RE: Basic Programming Help desired? > Geoff, > > My experience is with the various versions of MS Basic, not Powerbasic. > However, the following comments may help. > > Check the effects of the various compiler directives on the speed of the > routine. In particular, check the effects of the various error handlers. > Turning them off may increase the speed. > > I think your biggest hangup is creating a long string from your raw data -- > that's a huge amount of unnecessary conversions. Instead, you should > consider creating a binary file () and then writing > (stream) the individual bytes to the file as soon as you receive them from > the AD card. > > Here's a link to a routine that may give you some guidance: > http://www.vb-helper.com/howto_read_write_binary_file.html > > Also, check the utilities and tools that may have accompanied your AD card. > Often the manufacturer will supply tools and/or examples that allow you to > stream data directly from the card to disk. Check their website too. > > Some (most?) versions of Basic are intrinsically slow because they are not > truly compiled in the way FORTRAN would be. In your case it probably isn't > necessary, but if you really need the speed, then you should consider some > other language besides Basic -- e.g., C (C++), Fortran and ultimately, > Assembly. > > Regards, > -Tim- > > > -----Original Message----- > From: psn-l-request@.............. [mailto:psn-l-request@............... On > Behalf Of Geoff > Sent: Monday, May 05, 2008 12:18 AM > To: PSN > Subject: Basic Programming Help desired? > > Hello PSN Peoples; > > I am trying to make a routine > that will save an array of single > bytes to a raw data file on the hard > drive and do this as quickly as possible. > Below you will see a routine that works > very well for me but its too darn slow. > When the program enters this routine > it will linger for many seconds > appearently converting the data array > into the strings before eventually > actually saving the data into the file. > I do not understand the terrible long > time this routine seems to take. > > Can someone with more experience > please tell me what Im doing wrong > that takes so long ( literally several > seconds for only 32770 bytes total) to complete. > I would like a speed that rivals a BSAVE command. > > This is how i save my seismic data > to a raw 8 bit file > after recording it to the array > in RAM. > > Thanks for any help. > feel free ro email me direct. > > Regards; > geoff > > ********************************** > POWERBASIC FOR DOS COMPILER SOURCE CODE > > $LIB COM ON > $LIB FULLFLOAT ON > $LIB VGA ON > $ERROR BOUNDS ON > $ERROR NUMERIC ON > $ERROR OVERFLOW ON > $ERROR STACK ON > $CPU 80386 > $COM 1024 > $STRING 32 > $STACK 2048 > $SOUND 256 > $DYNAMIC > $COMPILE EXE "TEST.EXE" > $FLOAT NPX > $OPTIMIZE SPEED > $EVENT > $OPTION CNTLBREAK ON > > ' CREATE AN ARRAY FOR RAW DATA > DIM VIRTUAL DATA_1?(0:32780) > ' Fill the array with ascii text characters > ' So resulting file can be easily examined > ' with a hex editor normally this is the recording > FOR a = 0 to 32780 : DATA_1?(a) = ( 65 + a MOD 58 ) : NEXT a > ' Form a file path and name > FILE1$ = "c:\data\test.dat" > ' screen not necessary just habit > SCREEN 11 > ' below is the routine in question > tmpz1$ = "" > FOR ka = 0 to 32255 > tmpz1$ = tmpz1$ + chr$(DATA_1?(ka)) > NEXT ka > tmpz2$ = "" > FOR ka = 32256 to 32769 > tmpz2$ = tmpz2$ + chr$(DATA_1?(ka)) > NEXT ka > OPEN FILE1$ FOR BINARY AS #1 > SEEK #1,0 : PUT$ #1,tmpz1$ > SEEK #1,32256 : PUT$ #1,tmpz2$ > CLOSE #1 > tmpz1$ = "" : tmpz2$ = "" > ' task completed return to system > SYSTEM > > > ***************************** > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: Canie canie@........... Date: Mon, 05 May 2008 09:52:41 -0700 I've worked with basic programming for about 30 years.. no ms basic, but a flavor of basic.. and whenever we were trying to speed such things up, it was known that for-next loops were rather slow... You might play around with a while-wend statements to see if that executes and faster, or just use a counter and gotos... interesting test for timing of things.. Canie At 09:15 AM 5/5/2008, you wrote: >THANK you but this is not the problem I am addressing. >A/D is not the concern at this time. >ALL data is saved to an array that resides somewhere >in MSDOS EMS RAM. What I am trying to do is >save that array as fast as possible FROM RAM to a file >residing on hard disk. This lets me turn off the >disk while the recorder is running and turn on the drive >only for file operations ( permanent storage ). >I have always had troubles quickly dealing with >file formation and lots of bytes. >If you play with BSAVE command you will >find it is almost instant unlike my own programs. >If only I could make a program as fast as BSAVE >BASIC command then I could do anything I need to >in this regard very quickly and miss few samples >inbetween recordings. > >Immediately below is the routine which does this >operation as fast as I have ever done it. >Comments are welcome. > >Regards; >geoff > >************************* >$LIB COM ON >$LIB FULLFLOAT ON >$LIB VGA ON >$ERROR BOUNDS ON >$ERROR NUMERIC ON >$ERROR OVERFLOW ON >$ERROR STACK ON >$CPU 80386 >$COM 1024 >$STRING 32 >$STACK 2048 >$SOUND 256 >$DYNAMIC >$COMPILE EXE "TEST.EXE" >$FLOAT NPX >$OPTIMIZE SPEED >$EVENT >$OPTION CNTLBREAK ON > >DIM VIRTUAL DATA_1?(0:32780) > >' Create a test set of data >FOR a = 0 to 32780 : DATA_1?(a) = ( 65 + a MOD 58 ) : NEXT a >' Create the path and filename >FILE1$ = "c:\data\test.dat" >' Write The Array in EMS RAM To The File on HARD Drive >CLS >PRINT "NOW SAVING DATA TO FILE c:\data\test.dat " >OPEN FILE1$ FOR BINARY AS #1 >FOR ka = 0 to 7 > tmpz1$ = "" > For kb = 0 to 4095 > kc = (( ka * 4096 ) + kb ) > tmpz1$ = tmpz1$ + chr$(DATA_1?(kc)) > NEXT kb > kd = ( ka * 4096 ) > SEEK #1,kd : PUT$ #1,tmpz1$ >NEXT ka >tmpz1$ = "" >FOR ka = 32256 to 32769 > tmpz1$ = tmpz1$ + chr$(DATA_1?(ka)) >NEXT ka >SEEK #1,32256 : PUT$ #1,tmpz1$ >CLOSE #1 >tmpz1$ = "" >END >********* __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Mon, 5 May 2008 12:09:30 -0700 Roger Wilco Canie; I have found when dealing with the disk it matters how many bytes you can deal with in a single instruction/operation and that those bytes match the sector sizes on the disk itself. I think that one sector can be entirely written in a single write operation but if you use odd sizes it slows things down. Possibly the way the compiler does things is also important like DMA or Interrupt type programming. DMA between ram and disk is most probably the best way to go for a stable machine. But this would require assembly programming of a custom nature and Id have to go back to school to be able to do this. The sector sizes vary according to where you are on the disk and what the format type happens to be. It seems to me that powers of two relating to 512 bytes is possible the right thing to do. Someone has all the answers but finding a willing person to share such knowledge is very difficult for myself. Such expert people are typically too sensitive about sharing knowledge. They are capitalists with eyes that see only money and not true amateurs seeking and sharing knowledge. Thanks for your input. DMA = Direct memory access where you wind up the hard drive ( or whatever ) and it goes and gets its own data from ram by itself using the transfer times between machine (CPU) cycles. regards; geoff ----- Original Message ----- From: "Canie" To: Sent: Monday, May 05, 2008 9:52 AM Subject: Re: Basic Programming Help desired? > I've worked with basic programming for about 30 years.. no ms basic, > but a flavor of basic.. and whenever we were trying to speed such > things up, it was known that for-next loops were rather slow... > > You might play around with a while-wend statements to see if that > executes and faster, or just use a counter and gotos... interesting > test for timing of things.. > > Canie > > At 09:15 AM 5/5/2008, you wrote: >>THANK you but this is not the problem I am addressing. >>A/D is not the concern at this time. >>ALL data is saved to an array that resides somewhere >>in MSDOS EMS RAM. What I am trying to do is >>save that array as fast as possible FROM RAM to a file >>residing on hard disk. This lets me turn off the >>disk while the recorder is running and turn on the drive >>only for file operations ( permanent storage ). >>I have always had troubles quickly dealing with >>file formation and lots of bytes. >>If you play with BSAVE command you will >>find it is almost instant unlike my own programs. >>If only I could make a program as fast as BSAVE >>BASIC command then I could do anything I need to >>in this regard very quickly and miss few samples >>inbetween recordings. >> >>Immediately below is the routine which does this >>operation as fast as I have ever done it. >>Comments are welcome. >> >>Regards; >>geoff >> >>************************* >>$LIB COM ON >>$LIB FULLFLOAT ON >>$LIB VGA ON >>$ERROR BOUNDS ON >>$ERROR NUMERIC ON >>$ERROR OVERFLOW ON >>$ERROR STACK ON >>$CPU 80386 >>$COM 1024 >>$STRING 32 >>$STACK 2048 >>$SOUND 256 >>$DYNAMIC >>$COMPILE EXE "TEST.EXE" >>$FLOAT NPX >>$OPTIMIZE SPEED >>$EVENT >>$OPTION CNTLBREAK ON >> >>DIM VIRTUAL DATA_1?(0:32780) >> >>' Create a test set of data >>FOR a = 0 to 32780 : DATA_1?(a) = ( 65 + a MOD 58 ) : NEXT a >>' Create the path and filename >>FILE1$ = "c:\data\test.dat" >>' Write The Array in EMS RAM To The File on HARD Drive >>CLS >>PRINT "NOW SAVING DATA TO FILE c:\data\test.dat " >>OPEN FILE1$ FOR BINARY AS #1 >>FOR ka = 0 to 7 >> tmpz1$ = "" >> For kb = 0 to 4095 >> kc = (( ka * 4096 ) + kb ) >> tmpz1$ = tmpz1$ + chr$(DATA_1?(kc)) >> NEXT kb >> kd = ( ka * 4096 ) >> SEEK #1,kd : PUT$ #1,tmpz1$ >>NEXT ka >>tmpz1$ = "" >>FOR ka = 32256 to 32769 >> tmpz1$ = tmpz1$ + chr$(DATA_1?(ka)) >>NEXT ka >>SEEK #1,32256 : PUT$ #1,tmpz1$ >>CLOSE #1 >>tmpz1$ = "" >>END >>********* > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: Canie canie@........... Date: Mon, 05 May 2008 15:12:38 -0700 Yes - size of the data record can have such an effect.. all these little things that you'de wish the Microsoft engineers would know.. We always tried to do record sizes (of file definition sizes) of 64, 256, 512, 1024 bytes..for that reason - the disk writes would be faster.. And for some reason division is slower that multiplication.. so for certain things, rather than divide, we'de figure out how to multiply.. also these things can be compiler dependant I assume.. Canie At 12:09 PM 5/5/2008, you wrote: >Roger Wilco Canie; > >I have found when dealing with the disk >it matters how many bytes you can deal with >in a single instruction/operation and that those bytes >match the sector sizes on the disk itself. >I think that one sector can be entirely >written in a single write operation >but if you use odd sizes it slows things down. >Possibly the way the compiler does things >is also important like DMA or Interrupt >type programming. DMA between ram and disk >is most probably the best way to go for a >stable machine. But this would require >assembly programming of a custom nature >and Id have to go back to school to >be able to do this. >The sector sizes vary according to >where you are on the disk and what the >format type happens to be. >It seems to me that powers of two relating to >512 bytes is possible the right thing to do. >Someone has all the answers but finding >a willing person to share such knowledge >is very difficult for myself. Such expert people are >typically too sensitive about sharing knowledge. >They are capitalists with eyes that see only money >and not true amateurs seeking and sharing knowledge. >Thanks for your input. >DMA = Direct memory access where you wind up the hard >drive ( or whatever ) and it goes and gets its own data from ram >by itself using the transfer times between machine (CPU) cycles. >regards; >geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Mon, 5 May 2008 17:44:00 -0700 Canie, And Others of PSN Many thanks for your input; Here is what I have found and will use this routine within my main recording program. If I run this on my desktop which is a pc3200 ram and 3GHz pentium4 Prescott device CPU and ATA100 Hard drives I get a time of 0.164 seconds a wonderful time. But if i run this on the laptop I use to record seismic events I get a time 17 times slower or 2.856 seconds ( Toshiba Satellite 205CDS Laptop ) It appears I shall loose about 4 to 5 seconds or record time between file saves with all the delays. The drive on the laptop is normally off and must rev up prior to saving the file but thats only a second or so of time. Below is the Routine I will install at the end of my program you all are free to have and to hold it until death you part. It will love honor and obey you, I hope. ******************************************* ' FILENAME TEST.BAS ' POWERBASIC For DOS 3.5 SOURCE CODE $LIB COM ON $LIB FULLFLOAT ON $LIB VGA ON $ERROR BOUNDS ON $ERROR NUMERIC ON $ERROR OVERFLOW ON $ERROR STACK ON $CPU 80386 $COM 1024 $STRING 32 $STACK 2048 $SOUND 256 $DYNAMIC $COMPILE EXE "TEST.EXE" $FLOAT NPX $OPTIMIZE SPEED $EVENT $OPTION CNTLBREAK ON DIM VIRTUAL DATA_1?(0:32780) FOR a = 0 to 32780 : DATA_1?(a) = ( 65 + a MOD 58 ) : NEXT a FILE1$ = "c:\data\test.dat" START1 = TIMER OPEN FILE1$ FOR BINARY AS #1 FOR ka = 0 to 7 tmpz1$ = "" kc = ( ka * 4096 ) SEEK #1,kc FOR kb = 0 to 4095 kd = ( kc + kb ) tmpz1$ = tmpz1$ + chr$(DATA_1?(kd)) NEXT kb PUT$ #1,tmpz1$ NEXT ka tmpz1$ = "" SEEK #1,32768 FOR ka = 32768 to 32769 tmpz1$ = tmpz1$ + chr$(DATA_1?(ka)) NEXT ka PUT$ #1,tmpz1$ CLOSE #1 tmpz1$ = "" STOP1 = TIMER IF START1 > STOP1 THEN START1 = START1 + 86400 PRINT "FILE CREATION RUNTIME :"; ROUND(( STOP1 - START1 ) , 3 ) SLEEP 10 END ****************************************************8 I will bother you no more with this unless someone has more to say. Best regards; geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Tue, 6 May 2008 06:32:48 -0700 Many thanks Canie, I do not know if I have answered this yet but me thinks not. I will have to experiment myself from this point on to learn more since no one has exact answers I was looking for. There should be one fastest way of all to transfer data from an array to a hard disk file and no one seems to know what it is. If I could see how BASIC BSAVE command is working I may have my answer because it by far is the lightning fast quickness I wish to have. But when I tried the BSAVE command none of the data was in the correct order and saved were more bytes then I wanted to save. For me to unassemble the BSAVE routine would be a violation of the reverse engineering agreement in any licenses so that is out of the question for myself. I am using a Virtual Array ( Located In EMS Memory ) and not REAL MODE memory ( First 1MB ) and there is a possibility BSAVE may only function well in the REAL MODE instead of PROTECTED MODE ( EVERYTHING ABOVE 1MB ) . If I try to limit my entire program to REAL MODE then things may be faster too. The Originators of the IBM PC were more oriented to Business Administration then to science so security of design was way overboard and terribly subtracts from IBM PC performance. What is needed is the entire machine be REAL MODE without the stupid form of Paginated RAM and Interrupt ( TIME Sharing ) based design. They have tried to do too much with a serial CPU device which for best speed should only run one program at a time. Best Regards; geoff ----- Original Message ----- From: "Canie" To: Sent: Monday, May 05, 2008 3:12 PM Subject: Re: Basic Programming Help desired? > Yes - size of the data record can have such an effect.. all these > little things that you'de wish the Microsoft engineers would know.. > > We always tried to do record sizes (of file definition sizes) of 64, > 256, 512, 1024 bytes..for that reason - the disk writes would be faster.. > > And for some reason division is slower that multiplication.. so for > certain things, rather than divide, we'de figure out how to > multiply.. also these things can be compiler dependant I assume.. > > Canie > > At 12:09 PM 5/5/2008, you wrote: >>Roger Wilco Canie; >> >>I have found when dealing with the disk >>it matters how many bytes you can deal with >>in a single instruction/operation and that those bytes >>match the sector sizes on the disk itself. >>I think that one sector can be entirely >>written in a single write operation >>but if you use odd sizes it slows things down. >>Possibly the way the compiler does things >>is also important like DMA or Interrupt >>type programming. DMA between ram and disk >>is most probably the best way to go for a >>stable machine. But this would require >>assembly programming of a custom nature >>and Id have to go back to school to >>be able to do this. >>The sector sizes vary according to >>where you are on the disk and what the >>format type happens to be. >>It seems to me that powers of two relating to >>512 bytes is possible the right thing to do. >>Someone has all the answers but finding >>a willing person to share such knowledge >>is very difficult for myself. Such expert people are >>typically too sensitive about sharing knowledge. >>They are capitalists with eyes that see only money >>and not true amateurs seeking and sharing knowledge. >>Thanks for your input. >>DMA = Direct memory access where you wind up the hard >>drive ( or whatever ) and it goes and gets its own data from ram >>by itself using the transfer times between machine (CPU) cycles. >>regards; >>geoff > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Tue, 6 May 2008 10:05:10 -0700 The Following Results Found; I changed VIRTUAL Array to HUGE which I belive keeps everything below the DOS 1MB RAM boundary and then used a RANDOM instead of a BINARY OPEN command. It seems RANDOM is best for numbers and BINARY is best for Strings if you want to do things byte by byte in PowerBasic For DOS. EVERYTHING now becomes; $LIB COM ON $LIB FULLFLOAT ON $LIB VGA ON $ERROR BOUNDS ON $ERROR NUMERIC ON $ERROR OVERFLOW ON $ERROR STACK ON $CPU 80386 $COM 1024 $STRING 32 $STACK 2048 $SOUND 256 $DYNAMIC $COMPILE EXE "TEST.EXE" $FLOAT NPX $OPTIMIZE SPEED $EVENT $OPTION CNTLBREAK ON DIM HUGE DATA_1?(0:32769) FOR A = 0 to 32769 : DATA_1?(A) = ( 65 + A MOD 58 ) : NEXT A FILE1$ = "c:\data\test.dat" START1 = TIMER OPEN FILE1$ FOR RANDOM AS #1 LEN = 1 FOR A?? = 0 to 32769 PUT #1,A?? + 1,DATA_1?(A??) NEXT A?? CLOSE STOP1 = TIMER IF START1 > STOP1 THEN START1 = START1 + 86400 PRINT "FILE CREATION RUNTIME :"; ROUND(( STOP1 - START1 ) , 3 ) ' KILL FILE1$ SLEEP 3 END Best regards geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: ian ian@........... Date: Tue, 06 May 2008 18:32:33 +0100 Hi, I'm not familiar with this flavour of basic but 2 comments: Is the for loop meant to be 0 to 32769? Normally it would be 32767 for 15 bits - I don't know the application for this code. When coding loops, I found it better (runs faster) to repeat the code in the loop and reduce the number of times around the loop, 16 being optimum. For example: FOR A = 0 to 2047 DATA_1?(A*16 + 0) = ( 65 + (A*16 + 0) MOD 58 ) DATA_1?(A*16 + 1) = ( 65 + (A*16 + 1) MOD 58 ) DATA_1?(A*16 + 2) = ( 65 + (A*16 + 2) MOD 58 ) DATA_1?(A*16 + 3) = ( 65 + (A*16 + 3) MOD 58 ) DATA_1?(A*16 + 4) = ( 65 + (A*16 + 4) MOD 58 ) DATA_1?(A*16 + 5) = ( 65 + (A*16 + 5) MOD 58 ) DATA_1?(A*16 + 6) = ( 65 + (A*16 + 6) MOD 58 ) DATA_1?(A*16 + 7) = ( 65 + (A*16 + 7) MOD 58 ) DATA_1?(A*16 + 8) = ( 65 + (A*16 + 8) MOD 58 ) DATA_1?(A*16 + 9) = ( 65 + (A*16 + 9) MOD 58 ) DATA_1?(A*16 + 10) = ( 65 + (A*16 + 10) MOD 58 ) DATA_1?(A*16 + 11) = ( 65 + (A*16 + 11) MOD 58 ) DATA_1?(A*16 + 12) = ( 65 + (A*16 + 12) MOD 58 ) DATA_1?(A*16 + 13) = ( 65 + (A*16 + 13) MOD 58 ) DATA_1?(A*16 + 14) = ( 65 + (A*16 + 14) MOD 58 ) DATA_1?(A*16 + 15) = ( 65 + (A*16 + 15) MOD 58 ) NEXT A DATA_1?(32768) = ( 65 + 32768 MOD 58 ) DATA_1?(32769) = ( 65 + 32769 MOD 58 ) This isn't debugged or known to be syntactically correct. Might be worth trying though... Ian Geoff wrote: > The Following Results Found; > > I changed VIRTUAL Array to HUGE > which I belive keeps everything > below the DOS 1MB RAM boundary > and then used a RANDOM instead of a > BINARY OPEN command. It seems RANDOM > is best for numbers and BINARY > is best for Strings if you want to > do things byte by byte in PowerBasic For DOS. > EVERYTHING now becomes; > > $LIB COM ON > $LIB FULLFLOAT ON > $LIB VGA ON > $ERROR BOUNDS ON > $ERROR NUMERIC ON > $ERROR OVERFLOW ON > $ERROR STACK ON > $CPU 80386 > $COM 1024 > $STRING 32 > $STACK 2048 > $SOUND 256 > $DYNAMIC > $COMPILE EXE "TEST.EXE" > $FLOAT NPX > $OPTIMIZE SPEED > $EVENT > $OPTION CNTLBREAK ON > > DIM HUGE DATA_1?(0:32769) > FOR A = 0 to 32769 : DATA_1?(A) = ( 65 + A MOD 58 ) : NEXT A > FILE1$ = "c:\data\test.dat" > START1 = TIMER > OPEN FILE1$ FOR RANDOM AS #1 LEN = 1 > FOR A?? = 0 to 32769 > PUT #1,A?? + 1,DATA_1?(A??) > NEXT A?? > CLOSE > STOP1 = TIMER > IF START1 > STOP1 THEN START1 = START1 + 86400 > PRINT "FILE CREATION RUNTIME :"; ROUND(( STOP1 - START1 ) , 3 ) > ' KILL FILE1$ > SLEEP 3 > END > > Best regards > geoff > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Dale Hardy" photon1@........... Date: Wed, 7 May 2008 08:42:36 +1000 Geoff, I have been using RapidQ basic. Very ACTIVE user group with strong support and very helpful not too far removed from your basic regards Dale http://rapidq.phatcode.net/ ----- Original Message ----- From: "Geoff" To: Sent: Tuesday, May 06, 2008 2:15 AM Subject: Re: Basic Programming Help desired? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: My lehman type sensor is ready From: jonfr@......... Date: Thu, 8 May 2008 09:28:40 -0400 (EDT) Hi all My lehman type sensor is ready. I hope that it gives me up to 30 seconds peroid. But I won't know if that is the case of not until tomorrow when I put it online at home. Here are two pictures of it. http://www.jonfr.com/myndir/v/geology/seismometer/DSC00432.JPG.html http://www.jonfr.com/myndir/v/geology/seismometer/DSC00433.JPG.html If hit by a blank page, just press enter and it should load properly. The mass is about ~1.5kg. The arm is ~70 cm and the mass is located at the ~65 cm limit of it. I used to speaker magnets as damping magnest. The coil and the maget are from Larry. At current setting, I should be getting 0.135V from the coil, but that is just a guess. I will know for sure tomorrow. It appears to be higly sensitive. The damping appears to be working nicely. I will post more information tomorrow if needed. Regards. Jón Frímann. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Thu, 8 May 2008 11:17:28 -0700 Hello ian, Yes, Straight Line Code is almost always faster then is using subroutines or jumps. I notice here your math is all shift and adds Which is in reality all any digital computer does. When you tell a CPU to multiply or divide it only shifts right or left and adds positive or negative numbers. Some decimal numbers can never exactly be reproduced in binary form so there will most times be rounding errors. To reduce the rounding errors the business community dealing in money likes to use BCD " binary coded decimal" TRY to match exactly decimal 0.1 in binary numbers. Sort of like PI it seems to have no end. I wonder out loud here if PI has a number system base whatever that will come out with an end to it. Straight line code is terribly lengthy but the fastest way to go. That is basically what you say here as well as stick to binary math whenever possible. When saving to disk other things need to be considered like exactly how the controller microcode works or handles data and what will be fastest for transfer of data. I have noticed great differences in speed of various programs. The fastest save program I have ever seen relates to a program called SPOTMAU and backs up your system via DOS to an image file in whatever partition It will save at up to 900MB per Minute using FAT32 Drives. That is still much slower then an ATA100 is capable of moving data. I get the feeling that data is written several times over to the same location or things would be much faster than they are. My original question deals more with what technique will save a numerical array fastest to the hard disk drive. Id like to get 100MB/sec which I understand an ATA100 IDE controller & HDD can handle. Best Regards; geoff ----- Original Message ----- From: "ian" To: Sent: Tuesday, May 06, 2008 10:32 AM Subject: Re: Basic Programming Help desired? > Hi, > > I'm not familiar with this flavour of basic but 2 comments: > > Is the for loop meant to be 0 to 32769? Normally it would be 32767 for > 15 bits - I don't know the application for this code. > > When coding loops, I found it better (runs faster) to repeat the code in > the loop and reduce the number of times around the loop, 16 being > optimum. For example: > > FOR A = 0 to 2047 > DATA_1?(A*16 + 0) = ( 65 + (A*16 + 0) MOD 58 ) > DATA_1?(A*16 + 1) = ( 65 + (A*16 + 1) MOD 58 ) > DATA_1?(A*16 + 2) = ( 65 + (A*16 + 2) MOD 58 ) > DATA_1?(A*16 + 3) = ( 65 + (A*16 + 3) MOD 58 ) > DATA_1?(A*16 + 4) = ( 65 + (A*16 + 4) MOD 58 ) > DATA_1?(A*16 + 5) = ( 65 + (A*16 + 5) MOD 58 ) > DATA_1?(A*16 + 6) = ( 65 + (A*16 + 6) MOD 58 ) > DATA_1?(A*16 + 7) = ( 65 + (A*16 + 7) MOD 58 ) > DATA_1?(A*16 + 8) = ( 65 + (A*16 + 8) MOD 58 ) > DATA_1?(A*16 + 9) = ( 65 + (A*16 + 9) MOD 58 ) > DATA_1?(A*16 + 10) = ( 65 + (A*16 + 10) MOD 58 ) > DATA_1?(A*16 + 11) = ( 65 + (A*16 + 11) MOD 58 ) > DATA_1?(A*16 + 12) = ( 65 + (A*16 + 12) MOD 58 ) > DATA_1?(A*16 + 13) = ( 65 + (A*16 + 13) MOD 58 ) > DATA_1?(A*16 + 14) = ( 65 + (A*16 + 14) MOD 58 ) > DATA_1?(A*16 + 15) = ( 65 + (A*16 + 15) MOD 58 ) > NEXT A > DATA_1?(32768) = ( 65 + 32768 MOD 58 ) > DATA_1?(32769) = ( 65 + 32769 MOD 58 ) > > This isn't debugged or known to be syntactically correct. Might be > worth trying though... > > Ian > > Geoff wrote: >> The Following Results Found; >> >> I changed VIRTUAL Array to HUGE >> which I belive keeps everything >> below the DOS 1MB RAM boundary >> and then used a RANDOM instead of a >> BINARY OPEN command. It seems RANDOM >> is best for numbers and BINARY >> is best for Strings if you want to >> do things byte by byte in PowerBasic For DOS. >> EVERYTHING now becomes; >> >> $LIB COM ON >> $LIB FULLFLOAT ON >> $LIB VGA ON >> $ERROR BOUNDS ON >> $ERROR NUMERIC ON >> $ERROR OVERFLOW ON >> $ERROR STACK ON >> $CPU 80386 >> $COM 1024 >> $STRING 32 >> $STACK 2048 >> $SOUND 256 >> $DYNAMIC >> $COMPILE EXE "TEST.EXE" >> $FLOAT NPX >> $OPTIMIZE SPEED >> $EVENT >> $OPTION CNTLBREAK ON >> >> DIM HUGE DATA_1?(0:32769) >> FOR A = 0 to 32769 : DATA_1?(A) = ( 65 + A MOD 58 ) : NEXT A >> FILE1$ = "c:\data\test.dat" >> START1 = TIMER >> OPEN FILE1$ FOR RANDOM AS #1 LEN = 1 >> FOR A?? = 0 to 32769 >> PUT #1,A?? + 1,DATA_1?(A??) >> NEXT A?? >> CLOSE >> STOP1 = TIMER >> IF START1 > STOP1 THEN START1 = START1 + 86400 >> PRINT "FILE CREATION RUNTIME :"; ROUND(( STOP1 - START1 ) , 3 ) >> ' KILL FILE1$ >> SLEEP 3 >> END >> >> Best regards >> geoff >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of >> the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> >> > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Thu, 8 May 2008 11:30:46 -0700 Mr. Hardy; Thanks for the tip but I already have Power Basic both for Windows and DOS All I really need is to understand fully the programs I am using. It seems the Compiler I am using does not take advantage of the 586 (Pentium) code over the 386. It has been made for backwards compatability. Power Basic is quite good I just need to learn how to properly use it. I can not keep bouncing between various languages or I will spend my whole life and not accomplish any of my own personal goals. One of the biggest problems I see today is that this computer programming world has developed its own Tower Of Bable and you need to have an IQ OVER 100 to master anything involving more than one language. It is a good ol boys club for the gifted and leaves average joe blo layman out in the cold. Best regards; geoff ----- Original Message ----- From: "Dale Hardy" To: Sent: Tuesday, May 06, 2008 3:42 PM Subject: Re: Basic Programming Help desired? > Geoff, > I have been using RapidQ basic. Very ACTIVE user group with strong support > and very helpful > not too far removed from your basic > regards > Dale > http://rapidq.phatcode.net/ > > > > > ----- Original Message ----- > From: "Geoff" > To: > Sent: Tuesday, May 06, 2008 2:15 AM > Subject: Re: Basic Programming Help desired? > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: Kevin Brunt k.brunt@......... Date: Thu, 8 May 2008 20:52:58 +0100 (BST) Hi, This is my first post to the list, so my apologies if I've not got the etiquette right.... What I understand the question to be is, that there is an array of byte-sized integers which are to be written to a disk file exactly as they appear in memory. Having had a look at the manual at www.powerbasic.com what I think you need to use is the form of the PUT statement for binary files... PUT [#] fNum&, [RecPos], Arr() which, I think, will write the whole of the array out as one lump. Kevin >Date: Thu, 8 May 2008 11:30:46 -0700 >From: Geoff >All I really need is to understand fully >the programs I am using. >Power Basic is quite good I just need to learn >how to properly use it. > >I can not keep bouncing between various languages >or I will spend my whole life and not accomplish any >of my own personal goals. > >One of the biggest problems I see today >is that this computer programming world >has developed its own Tower Of Bable >and you need to have an IQ OVER 100 >to master anything involving more than one language. >It is a good ol boys club for the gifted and >leaves average joe blo layman out in the cold. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: SAVING SEISMIC DATA FROM BASIC COMPILED PROGRAM From: "Geoff" gmvoeth@........... Date: Thu, 8 May 2008 13:48:18 -0700 Hello PSN; FYI I have looked more into BSAVE by playing around with it and found it to be the single fastest way to save an array of one byte data. The two files below include everything I know and is yours to play with ( NO GUARANTEES ) all I can tell you is it is the best of all options I have looked at. If you have troubles downloading I will be happy to email you either or both as an attachment. It was able to save an entire 30 minutes of my data generated here at GVA in less than a tic of the timer function = (3600/65540)seconds . http://gmvoeth.home.mchsi.com/testdump.zip http://gmvoeth.home.mchsi.com/testdump.rar BEST regards, geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Thu, 8 May 2008 13:55:50 -0700 Hello Mr. Brunt ; Yes you are basically correct. But speed of saving the array is the real issue. I have tried just about everything but found nothing faster than using the BSAVE command. I have posted another email with links to the files in question. The given programs in ZIP or RAR form contain all I can tell you. Best regards; geoff ps; I never tried to put a complete array in a single operation. Did not know that was possible. I still think BSAVE will be faster. ----- Original Message ----- From: "Kevin Brunt" To: "psn-l" Sent: Thursday, May 08, 2008 12:52 PM Subject: Re: Basic Programming Help desired? > > Hi, > > This is my first post to the list, so my apologies if I've not got the etiquette > right.... > > What I understand the question to be is, that there is an array of byte-sized integers which are to be written to a disk file > exactly as they appear in memory. > > Having had a look at the manual at www.powerbasic.com what I think you need to use is the form of the PUT statement for binary > files... > > PUT [#] fNum&, [RecPos], Arr() > > which, I think, will write the whole of the array out as one lump. > > Kevin > >>Date: Thu, 8 May 2008 11:30:46 -0700 >>From: Geoff > >>All I really need is to understand fully >>the programs I am using. > >>Power Basic is quite good I just need to learn >>how to properly use it. >> >>I can not keep bouncing between various languages >>or I will spend my whole life and not accomplish any >>of my own personal goals. >> >>One of the biggest problems I see today >>is that this computer programming world >>has developed its own Tower Of Bable >>and you need to have an IQ OVER 100 >>to master anything involving more than one language. >>It is a good ol boys club for the gifted and >>leaves average joe blo layman out in the cold. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My lehman type sensor is ready From: Pete Rowe ptrowe@......... Date: Thu, 8 May 2008 14:25:05 -0700 (PDT) WOW, Jon, what a nice job. Let us know how well it works. Pete --- On Thu, 5/8/08, jonfr@......... wrote: > From: jonfr@......... > Subject: My lehman type sensor is ready > To: psn-l@.............. > Date: Thursday, May 8, 2008, 6:28 AM > Hi all >=20 > My lehman type sensor is ready. I hope that it gives me up > to 30 seconds > peroid. But I won't know if that is the case of not > until tomorrow when I > put it online at home. >=20 > Here are two pictures of it. >=20 > http://www.jonfr.com/myndir/v/geology/seismometer/DSC00432.JPG.html > http://www.jonfr.com/myndir/v/geology/seismometer/DSC00433.JPG.html >=20 > If hit by a blank page, just press enter and it should load > properly. >=20 > The mass is about ~1.5kg. The arm is ~70 cm and the mass is > located at the > ~65 cm limit of it. >=20 > I used to speaker magnets as damping magnest. The coil and > the maget are > from Larry. At current setting, I should be getting 0.135V > from the coil, > but that is just a guess. I will know for sure tomorrow. >=20 > It appears to be higly sensitive. The damping appears to be > working nicely. >=20 > I will post more information tomorrow if needed. >=20 > Regards. > J=F3n Fr=EDmann. >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email PSN-L-REQUEST@.............. with=20 > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more > information.=0A=0A=0A ______________________________________________= ______________________________________=0ABe a better friend, newshound, and= =0Aknow-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;= _ylt=3DAhu06i62sR8HDtDypao8Wcj9tAcJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My lehman type sensor is ready From: ChrisAtUpw@....... Date: Thu, 8 May 2008 17:34:18 EDT In a message dated 2008/05/08, jonfr@......... writes: > My lehman type sensor is ready. I hope that it gives me up to 30 seconds > peroid. But I won't know if that is the case of not until tomorrow when I > put it online at home. Hi Jon, Sorry, but you have made a couple of design mistakes with your Lehman. The coil as shown in the photograph WOULD be sensitive IF the magnet were able to move in the direction of the arm, but NOT at right angles to it! Turn the magnet at right angles and put the coil out to one side. You get a true linear signal as the coil approaches or recedes from the open jaws of the magnet, NOT when the magnet jaws stay at ~the same distance from the coil, moving parallel to the sufaces of the jaws. The setup as shown will only have a very small and non linear sensitivity to small movements. It will give a signal of double the frequency. You definitely need to change it. Putting the magnet on the arm and the coil on the frame allows the arm to be sensitive to changes in the Earth's magnetic field, to surges in the electricity supply cables, to passing trucks and cars.... With the existing setup, you will get quite a noisy signal. It is VASTLY PREFERABLE to put the coil on the arm and the magnet on the base frame! Using a U magnet and a coil will only give about 1/10 the signal that you can get from quad NdFeB magnets on mild steel backing plates. The arm will be sensitive to rocking motions about it's axis. I put a cross bar on the arm close to the mass and a V suspension up to the top hinge to avoid this problem. I can't see from the photo how you have constructed the bottom bearing, or the top suspension. The top suspension is as important as the bottom bearing in getting a long period. Regards, Chris Chapman In a me= ssage dated 2008/05/08, jonfr@......... writes:

My lehman type sensor is ready.= I hope that it gives me up to 30 seconds
peroid. But I won't know if that is the case of not until tomorrow when I put it online at home.


Hi Jon,

       Sorry, but you have made a couple of de= sign mistakes with your Lehman.

       The coil as shown in the photograph WOU= LD be sensitive IF the magnet were able to move in the direction of the arm,= but NOT at right angles to it!
       Turn the magnet at right angles and put= the coil out to one side. You get a true linear signal as the coil approach= es or recedes from the open jaws of the magnet, NOT when the magnet jaws sta= y at ~the same distance from the coil, moving parallel to the sufaces of the= jaws.
       The setup as shown will only have a ver= y small and non linear sensitivity to small movements. It will give a signal= of double the frequency. You definitely need to change it.

       Putting the magnet on the arm and the c= oil on the frame allows the arm to be sensitive to changes in the Earth's ma= gnetic field, to surges in the electricity supply cables, to passing trucks=20= and cars....  With the existing setup, you will get quite a noisy signa= l. It is VASTLY PREFERABLE to put the coil on the arm and the magnet on the=20= base frame!

       Using a U magnet and a coil will only g= ive about 1/10 the signal that you can get from quad NdFeB magnets on mild s= teel backing plates.

       The arm will be sensitive to rocking mo= tions about it's axis. I put a cross bar on the arm close to the mass and a=20= V suspension up to the top hinge to avoid this problem.

       I can't see from the photo how you have= constructed the bottom bearing, or the top suspension. The top suspension i= s as important as the bottom bearing in getting a long period.

       Regards,
 
       Chris Chapman     <= /FONT> Subject: Re: My lehman type sensor is ready From: ian ian@........... Date: Thu, 08 May 2008 22:38:57 +0100 Hi, I was concerned about how you will be able to easily adjust the level of the base. This will need to be done from time to time. Usually there is some adjustment mechanism protruding above the base. Cheers Ian ChrisAtUpw@....... wrote: > In a message dated 2008/05/08, jonfr@......... writes: > >> My lehman type sensor is ready. I hope that it gives me up to 30 seconds >> peroid. But I won't know if that is the case of not until tomorrow when I >> put it online at home. > > > Hi Jon, > > Sorry, but you have made a couple of design mistakes with your > Lehman. > > The coil as shown in the photograph WOULD be sensitive IF the > magnet were able to move in the direction of the arm, but NOT at right > angles to it! > Turn the magnet at right angles and put the coil out to one > side. You get a true linear signal as the coil approaches or recedes > from the open jaws of the magnet, NOT when the magnet jaws stay at > ~the same distance from the coil, moving parallel to the sufaces of > the jaws. > The setup as shown will only have a very small and non linear > sensitivity to small movements. It will give a signal of double the > frequency. You definitely need to change it. > > Putting the magnet on the arm and the coil on the frame allows > the arm to be sensitive to changes in the Earth's magnetic field, to > surges in the electricity supply cables, to passing trucks and > cars.... With the existing setup, you will get quite a noisy signal. > It is VASTLY PREFERABLE to put the coil on the arm and the magnet on > the base frame! > > Using a U magnet and a coil will only give about 1/10 the > signal that you can get from quad NdFeB magnets on mild steel backing > plates. > > The arm will be sensitive to rocking motions about it's axis. I > put a cross bar on the arm close to the mass and a V suspension up to > the top hinge to avoid this problem. > > I can't see from the photo how you have constructed the bottom > bearing, or the top suspension. The top suspension is as important as > the bottom bearing in getting a long period. > > Regards, > > Chris Chapman Hi,

I was concerned about how you will be able to easily adjust the level of the base.  This will need to be done from time to time.  Usually there is some adjustment mechanism protruding above the base.

Cheers

Ian

ChrisAtUpw@....... wrote:
In a message dated 2008/05/08, jonfr@......... writes:

My lehman type sensor is ready. I hope that it gives me up to 30 seconds
peroid. But I won't know if that is the case of not until tomorrow when I
put it online at home.


Hi Jon,

       Sorry, but you have made a couple of design mistakes with your Lehman.

       The coil as shown in the photograph WOULD be sensitive IF the magnet were able to move in the direction of the arm, but NOT at right angles to it!
       Turn the magnet at right angles and put the coil out to one side. You get a true linear signal as the coil approaches or recedes from the open jaws of the magnet, NOT when the magnet jaws stay at ~the same distance from the coil, moving parallel to the sufaces of the jaws.
       The setup as shown will only have a very small and non linear sensitivity to small movements. It will give a signal of double the frequency. You definitely need to change it.

       Putting the magnet on the arm and the coil on the frame allows the arm to be sensitive to changes in the Earth's magnetic field, to surges in the electricity supply cables, to passing trucks and cars....  With the existing setup, you will get quite a noisy signal. It is VASTLY PREFERABLE to put the coil on the arm and the magnet on the base frame!

       Using a U magnet and a coil will only give about 1/10 the signal that you can get from quad NdFeB magnets on mild steel backing plates.

       The arm will be sensitive to rocking motions about it's axis. I put a cross bar on the arm close to the mass and a V suspension up to the top hinge to avoid this problem.

       I can't see from the photo how you have constructed the bottom bearing, or the top suspension. The top suspension is as important as the bottom bearing in getting a long period.

       Regards,
 
       Chris Chapman    
Subject: Fwd: Re: Basic Programming Help desired? From: Kevin Brunt k.brunt@......... Date: Thu, 8 May 2008 22:50:18 +0100 (BST) Hi, I think that you'll find that PUTting a 32768 byte array will be broadly comparable in time to BSAVEing the same array. The timing issues that you have been having are almost certainly due to the manipulation of individual array elements. Your first program was appending each byte to the end of a string one-by-one; I suspect that appending a byte to an N byte string consists of creating a new N+1 byte string, copying the N byte string to it and adding the new byte to the end - the original N byte string is then discarded. The observed delays are due to the repeated copying. Your later program wrote one byte at a time to the file; since there will be a (largely) fixed overhead for each call to PUT, 2^15 calls to PUT takes a lot longer than one call. Incidentally, I've been lurking in the PSN-L archives because I've been working on a PDP-11 (in a museum) that used to be used for seismic processing. The equivalent program to yours in PDP-11 assembler (for the RT-11 operating system) is probably no longer than your BASIC programs, and RT-11 can perform the write-to-disk while the program is filling up the next buffer. (Admittedly, the PDP-11 has 4 6-foot high 19-inch cabinets, each with its own mains lead....) Kevin >Date: Thu, 8 May 2008 13:55:50 -0700 >From: Geoff >Hello Mr. Brunt ; >Yes you are basically correct. >But speed of saving the array is the real issue. >I have tried just about everything but found >nothing faster than using the BSAVE command. >ps; I never tried to put a complete array in a single >operation. Did not know that was possible. >I still think BSAVE will be faster. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My lehman type sensor is ready From: jonfr@......... Date: Thu, 8 May 2008 18:28:19 -0400 (EDT) Hi Chris The arm moves freely in both direction (Horizontal). But that direction is the assumed default one, rather the vertical one, that also exist on the arm, it was not unexpected behavior as I did see it in the test sensor too. But it doesn't do so easy. I will know tomorrow what movement is the default one. I know about the axis moving strongly to the sides. But the damping magnets limit that movement greatly, it needs a strong force (at least a push of few cm) to move it, that type of push should not happen during a earthquake detection. I did put the coil in the base, rather then it's arm because the coil fits there better, given the U type magnet that I use (this also gives me voltage of 0.135 as it is on the picture). A equipment is magnetic sensitive is going to stay that way regardless of the setup, most setups I have seen show this type of background noise (there plots show it). I will see tomorrow how well this design is going to perform. The helicorder for the sensor is going online after I have done the basic working tests on him. The sensitivity test is going to be when the next big earthquake happens. To see a bigger picture of the seismometer you can choose the maximum size of 1200x1600 in the gallery. I will post better pictures tomorrow of the sensor. Regards. Jón Fríman. > In a message dated 2008/05/08, jonfr@......... writes: > >> My lehman type sensor is ready. I hope that it gives me up to 30 seconds >> peroid. But I won't know if that is the case of not until tomorrow when >> I >> put it online at home. > > Hi Jon, > > Sorry, but you have made a couple of design mistakes with your > Lehman. > > The coil as shown in the photograph WOULD be sensitive IF the > magnet > were able to move in the direction of the arm, but NOT at right angles to > it! > Turn the magnet at right angles and put the coil out to one side. > You > get a true linear signal as the coil approaches or recedes from the open > jaws > of the magnet, NOT when the magnet jaws stay at ~the same distance from > the > coil, moving parallel to the sufaces of the jaws. > The setup as shown will only have a very small and non linear > sensitivity to small movements. It will give a signal of double the > frequency. You > definitely need to change it. > > Putting the magnet on the arm and the coil on the frame allows the > arm > to be sensitive to changes in the Earth's magnetic field, to surges in the > electricity supply cables, to passing trucks and cars.... With the > existing > setup, you will get quite a noisy signal. It is VASTLY PREFERABLE to put > the coil > on the arm and the magnet on the base frame! > > Using a U magnet and a coil will only give about 1/10 the signal > that > you can get from quad NdFeB magnets on mild steel backing plates. > > The arm will be sensitive to rocking motions about it's axis. I put > a > cross bar on the arm close to the mass and a V suspension up to the top > hinge > to avoid this problem. > > I can't see from the photo how you have constructed the bottom > bearing, or the top suspension. The top suspension is as important as the > bottom > bearing in getting a long period. > > Regards, > > Chris Chapman > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Another New Lehman From: tchannel1@............ Date: Thu, 8 May 2008 21:38:31 -0600 Hi Folks, I have also built another Lehman. I was disappointed that I = did not get the 6.8M Japan May 7. It has a proven hinge, top and bottom. Proven in that I have used this = approach before several times and it was successful. ball bearing for = the bottom and wire for the top. The period is set at 20 seconds, and this was difficult, but I got it. The coil is 3600 turn and magnets are also proven design. The boom is pointing East West. The damping is as expected. I did get this earthquake on two other sensors one vertical and one tilt = meter (just a 48" pendulum) swinging East West. Q. Could it be over damped? Q. With the period at 20 second, could this be too high? Too high for = this earthquake? Q. Could it be the base on which the sensor is position? It is carpet, = on top of the carpet are concrete blocks, SS pads, and the sensor set on = these. I have used this on many other short period sensor, and it = works for those. I see nothing wrong. It does record all the road construction, and my = movements around the room. Thanks for you suggestions. Ted
Hi Folks,  I have also built = another=20 Lehman.  I was disappointed that I did not get the 6.8M Japan May=20 7.
 
It has a proven hinge, top and = bottom.  =20 Proven in that I have used this approach before several times and it was = successful.  ball bearing for the bottom and wire for the = top.
 
The period is set at 20 seconds, and = this was=20 difficult, but I got it.
The coil is 3600 turn and magnets are = also proven=20 design.
 
The boom is pointing East = West.
The damping is as = expected.
 
I did get this earthquake on two other = sensors one=20 vertical and one tilt meter (just a 48" pendulum) swinging East=20 West.
 
Q.  Could it be over = damped?
Q.  With the period at 20 second, = could this=20 be too high? Too high for this earthquake?
Q.  Could it be the base on which = the sensor=20 is position?  It is carpet, on top of the carpet are concrete = blocks, SS=20 pads, and the sensor set on these.   I have used this on many = other=20 short period sensor, and it works for those.
 
I see nothing wrong.   It = does record all=20 the road construction, and my movements around the room.
 
Thanks for you = suggestions.
 
Ted
Subject: Re: Another New Lehman From: ChrisAtUpw@....... Date: Fri, 9 May 2008 00:16:06 EDT In a message dated 2008/05/09, tchannel1@............ writes: > It has a proven hinge, top and bottom. Proven in that I have used this > approach before several times and it was successful. ball bearing for the > bottom and wire for the top. Hi Ted, What have you used for the hard counterface for the ball bearing? I use either a polished tungaten carbide triangular tool tip or a SS scalpel blade, stuck in place with acrylic glue. > The period is set at 20 seconds, and this was difficult, but I got it. This should not be difficult. > The coil is 3600 turn and magnets are also proven design. > The boom is pointing East West. > The damping is as expected. > I did get this earthquake on two other sensors one vertical and one tilt > meter (just a 48" pendulum) swinging East West. > > Q. Could it be over damped? > Q. With the period at 20 second, could this be too high? Too high for this > earthquake? > Q. Could it be the base on which the sensor is position? It is carpet, on > top of the carpet are concrete blocks, SS pads, and the sensor set on these. > I have used this on many other short period sensor, and it works for those. > > I see nothing wrong. It does record all the road construction, and my > movements around the room. You can easily check the damping. Push the boom 10 mm to one side with a pencil or similar and release it. It should swing about 1/2 mm past the zero position. I use a magnifying glass and a transparent ruler to observe this. You should have seen the Love waves. Regards, Chris Chapman In a me= ssage dated 2008/05/09, tchannel1@............ writes:

It has a proven hinge, top and=20= bottom.   Proven in that I have used this approach before several=20= times and it was successful.  ball bearing for the bottom and wire for=20= the top.


Hi Ted,

       What have you used for the hard counter= face for the ball bearing? I use either a polished tungaten carbide triangul= ar tool tip or a SS scalpel blade, stuck in place with acrylic glue.
<= FONT COLOR=3D"#000000" BACK=3D"#ffffff" style=3D"BACKGROUND-COLOR: #ffffff"= SIZE=3D3 PTSIZE=3D12 FAMILY=3D"SANSSERIF" FACE=3D"Arial" LANG=3D"0">

The period is set at 20 second= s, and this was difficult, but I got it.


       This should not be difficult.

The coil is 3600 turn and magn= ets are also proven design.
The boom is pointing East West.
The damping is as expected.
I did get this earthquake on two other sensors one vertical and one tilt me= ter (just a 48" pendulum) swinging East West.

Q.  Could it be over damped?
Q.  With the period at 20 second, could this be too high? Too high for= this earthquake?
Q.  Could it be the base on which the sensor is position?  It is=20= carpet, on top of the carpet are concrete blocks, SS pads, and the sensor se= t on these.   I have used this on many other short period sensor,=20= and it works for those.

I see nothing wrong.   It does record all the road construction,=20= and my movements around the room.


       You can easily check the damping. Push=20= the boom 10 mm to one side with a pencil or similar and release it. It shoul= d swing about 1/2 mm past the zero position. I use a magnifying glass and a=20= transparent ruler to observe this.

       You should have seen the Love waves.
       Regards,

       Chris Chapman
Subject: Re: Fwd: Re: Basic Programming Help desired? From: ian ian@........... Date: Fri, 09 May 2008 07:42:12 +0100 Hi Kevin, I used the inline code example (I posted earlier) on PDP 11 computers. The machines were actually real-time LSI-11 SBCs running Micropower Pascal/assembler developed on a pdp 11 (with twin rlo2 disks) development machine. The application was to control, read and process images from what was then (1986) the worlds highest resolution (3596 pixels) astronomy infra-red camera, cooled to -200C on, what was then, the worlds largest infra-red telescope (UKIRT - 3.8m) in Hawai'i. I wrote the time critical parts in assembler and the rest in Pascal. As for the current PSN problem, I would suggest scrapping basic and windows and going for a Linux machine and program in C. Cheers Ian > > Incidentally, I've been lurking in the PSN-L archives because I've been working on a PDP-11 (in a museum) that used to be used for seismic processing. The equivalent program to yours in PDP-11 assembler (for the RT-11 operating system) is probably no longer than your BASIC programs, and RT-11 can perform the write-to-disk while the program is filling up the next buffer. (Admittedly, the PDP-11 has 4 6-foot high 19-inch cabinets, each with its own mains lead....) > > Kevin > > >> Date: Thu, 8 May 2008 13:55:50 -0700 >> From: Geoff >> > > >> Hello Mr. Brunt ; >> Yes you are basically correct. >> But speed of saving the array is the real issue. >> I have tried just about everything but found >> nothing faster than using the BSAVE command. >> > > >> ps; I never tried to put a complete array in a single >> operation. Did not know that was possible. >> I still think BSAVE will be faster. >> > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > > Hi Kevin,

I used the inline code example (I posted earlier) on PDP 11 computers.  The machines were actually real-time LSI-11 SBCs running Micropower Pascal/assembler developed on a pdp 11 (with twin rlo2 disks) development machine.  The application was to control, read and process images from what was then (1986) the worlds highest resolution (3596 pixels) astronomy infra-red camera, cooled to -200C on, what was then, the worlds largest infra-red telescope (UKIRT - 3.8m) in Hawai'i.

I wrote the time critical parts in assembler and the rest in Pascal.  As for the current PSN problem, I would suggest scrapping basic and windows and going for a Linux machine and program in C.

Cheers

Ian

Incidentally, I've been lurking in the PSN-L archives because I've been working on a PDP-11 (in a museum) that used to be used for seismic processing. The equivalent program to yours in PDP-11 assembler (for the RT-11 operating system) is probably no longer than your BASIC programs, and RT-11 can perform the write-to-disk while the program is filling up the next buffer. (Admittedly, the PDP-11 has 4 6-foot high 19-inch cabinets, each with its own mains lead....)

Kevin

  
Date: Thu, 8 May 2008 13:55:50 -0700
From: Geoff <gmvoeth@...........>  
    

  
Hello Mr. Brunt ;
Yes you are basically correct.
But speed of saving the array is the real issue.
I have tried just about everything but found
nothing faster than using the BSAVE command.
    

  
ps; I never tried to put a complete array in a single
operation. Did not know that was possible.
I still think BSAVE will be faster.
    
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with 
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.


  
Subject: Re: Basic Programming Help desired? From: Kevin Brunt k.brunt@......... Date: Fri, 9 May 2008 11:15:36 +0100 (BST) Hi, While I am not going to argue against the "unrolling" of the code within a loop, my take on it is that it is something that a good optimising compiler will do for you. In your example, I suspect that the cost of the repeated "multiply-by-sixteen" operations would lose a lot of the time saved by reducing the amount of "iteration overhead". I don't think that a "Linux plus C" approach will serve Geoff's purpose. Apart from the fact that he obviously would rather get on with the seismology, rather than learning another programming language, he's wanting to run his data capture system on a low-spec machine (retired from other uses, I suspect). Kevin ---- Original message ---- >Date: Fri, 09 May 2008 07:42:12 +0100 >From: ian ian@... > I used the inline code example (I posted earlier) on > PDP 11 computers. > I wrote the time critical parts in assembler and the > rest in Pascal. As for the current PSN problem, I > would suggest scrapping basic and windows and going > for a Linux machine and program in C. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: ian ian@........... Date: Fri, 09 May 2008 16:04:25 +0100 Hi, a good compiler might well optimise it out but developing fast code involves a bit of trial and error, which is why I suggested trying it. If it doesn't give a useful gain, then just take it out again. Compilers are mysterious beasts. I suspect that Basic compilers will be amongst the most bestial. :-) I can understand the initial deterrent of migrating to another system but if you use the right tools then you'll get the best results. When Linux first came out, I ran it on an old 486 machine. These days, the slowest Linux machine I'm running is a 586 220 MHz - it just sits there, month after month, doing its job! Ian Kevin Brunt wrote: > Hi, > > While I am not going to argue against the "unrolling" of the code within a loop, my take on it is that it is something that a good optimising compiler will do for you. In your example, I suspect that the cost of the repeated "multiply-by-sixteen" operations would lose a lot of the time saved by reducing the amount of "iteration overhead". > > I don't think that a "Linux plus C" approach will serve Geoff's purpose. Apart from the fact that he obviously would rather get on with the seismology, rather than learning another programming language, he's wanting to run his data capture system on a low-spec machine (retired from other uses, I suspect). > > Kevin > > ---- Original message ---- > >> Date: Fri, 09 May 2008 07:42:12 +0100 >> From: ian ian@... >> > > >> I used the inline code example (I posted earlier) on >> PDP 11 computers. >> > > >> I wrote the time critical parts in assembler and the >> rest in Pascal. As for the current PSN problem, I >> would suggest scrapping basic and windows and going >> for a Linux machine and program in C. >> > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > > Hi,

a good compiler might well optimise it out but developing fast code involves a bit of trial and error, which is why I suggested trying it.  If it doesn't give a useful gain, then just take it out again.  Compilers are mysterious beasts.  I suspect that Basic compilers will be amongst the most bestial.  :-)

I can understand the initial deterrent of migrating to another system but if you use the right tools then you'll get the best results.  When Linux first came out, I ran it on an old 486 machine.  These days, the slowest Linux machine I'm running is a 586 220 MHz - it just sits there, month after month, doing its job!

Ian

Kevin Brunt wrote:
Hi,

While I am not going to argue against the "unrolling" of the code within a loop, my take on it is that it is something that a good optimising compiler will do for you. In your example, I suspect that the cost of the repeated "multiply-by-sixteen" operations would lose a lot of the time saved by reducing the amount of "iteration overhead".

I don't think that a "Linux plus C" approach will serve Geoff's purpose. Apart from the fact that he obviously would rather get on with the seismology, rather than learning another programming language, he's wanting to run his data capture system on a low-spec machine (retired from other uses, I suspect).

Kevin

---- Original message ----
  
Date: Fri, 09 May 2008 07:42:12 +0100
From: ian ian@...
    

  
  I used the inline code example (I posted earlier) on
  PDP 11 computers.
    

  
  I wrote the time critical parts in assembler and the
  rest in Pascal.  As for the current PSN problem, I
  would suggest scrapping basic and windows and going
  for a Linux machine and program in C.
    
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with 
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.


  
Subject: Re: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Fri, 9 May 2008 14:28:49 -0700 Hello Cruel World; I have learned by simply changing my arrays from Virtual ( EMS MEMORY ) to HUGE ( REAL MODE UNDER 1MB ) all my routines relating to arrays is faster by like 17X faster. There is something rotten in denmark in regards to memory management over 1 MB. I got this fft routine that now completes 128 lines of results in one second instead of 17 seconds. Now I have this PowerBasic for Windows that I have never tried but understand is faster code but it will not run under DOS as i remember and you need to make DLLs and the like which are foreign to my way of thinking. Why the heck dont the world of science beat the world of business into a corner and create a decent operating system for science oriented persons. We do not need all that security garbage like the money people do ( meaning Protected MODE ). geoff ----- Original Message ----- From: "Kevin Brunt" To: "psn-l" Sent: Thursday, May 08, 2008 2:50 PM Subject: Fwd: Re: Basic Programming Help desired? > > Hi, > > I think that you'll find that PUTting a 32768 byte array will be broadly comparable in time to BSAVEing the same array. > > The timing issues that you have been having are almost certainly due to the manipulation of individual array elements. Your first > program was appending each byte to the end of a string one-by-one; I suspect that appending a byte to an N byte string consists of > creating a new N+1 byte string, copying the N byte string to it and adding the new byte to the end - the original N byte string is > then discarded. The observed delays are due to the repeated copying. > > Your later program wrote one byte at a time to the file; since there will be a (largely) fixed overhead for each call to PUT, 2^15 > calls to PUT takes a lot longer than one call. > > Incidentally, I've been lurking in the PSN-L archives because I've been working on a PDP-11 (in a museum) that used to be used for > seismic processing. The equivalent program to yours in PDP-11 assembler (for the RT-11 operating system) is probably no longer > than your BASIC programs, and RT-11 can perform the write-to-disk while the program is filling up the next buffer. (Admittedly, > the PDP-11 has 4 6-foot high 19-inch cabinets, each with its own mains lead....) > > Kevin > >>Date: Thu, 8 May 2008 13:55:50 -0700 >>From: Geoff > >>Hello Mr. Brunt ; >>Yes you are basically correct. >>But speed of saving the array is the real issue. >>I have tried just about everything but found >>nothing faster than using the BSAVE command. > >>ps; I never tried to put a complete array in a single >>operation. Did not know that was possible. >>I still think BSAVE will be faster. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My lehman type sensor is ready From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sat, 10 May 2008 00:11:47 +0000 Hi all The lehman type sensor is up and running. However I have found one bad bug in it. Where the arm as attached to the arm where the mass is. I need to make it shorter (I think, at least so I can get it to hold the mass up properly) and attach it to the mass arm it self to hold it up. But the current attachment can't hold up the mass, that did destory the hoding inside of it. The second issue that I might have is that I am not sure if the damping is correct or not. Using Winquake FFT feature it appears that the seismomter has a natrual frequancy of around 1Hz but it goes down to 10 seconds. This is a second bug that I also need to fix somehow. As I am looking for up to 30 second period. I hope to fix the first bug on monday, I might also do some other modifactions to the sensor to make it more sensitive. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: The UK, "Evolution" brand chop saw for our seismometer steel and other metals/uses From: "meredith lamb" paleoartifact@......... Date: Fri, 9 May 2008 20:53:34 -0600 Hi all, This seems like a very interesting fast cutting 14" circular cut-off or chop saw, as it supposedly cuts 1/4" thick unhardened steel; which could be quite useful for those home hard to do projects like straight cutting the steel plates for the neodymium pickup magnets and/or seismometer dampening. There is some amazing online videos of its use in action. Amazing is a very common term I see from a variety of sellers on their various web sites. Specifically its the (blue label) steel cutting blade, but other blades can be used for other metals. They also have another blue label blade for thin steel sheet metal. The blades have 1" diameter bores, which might fit other saws, but, the "other chop saw" motor speed needs to around 1500rpm via gear reduction. There is a web variety of sellers. Even Sears (USA) sells "online only" the RAGE 2 chop saw; but unfortunately without the best (blue label) steel blade, at a web low price of $279.00...you would need to get the "best" blue label steel blade via other sellers on the web. Sears also sells the RAGE 3 multipurpose compound sliding 10" miter saw for $299.99; without again, the "best" (blue label) steel blade. The common shown orange label blades seem to be general multi-purpose metal cutting blades. The RAGE 3 blade turns at 2500 rpm, but only lasts roughly ~1/4 the cuts of the RAGE 2; but might be more useful for other projects with all its more extensive setup options. A good starting reference is below, and also shows a variety of metal blades: http://www.evolutiononlineshop.com/store/index.cfm Specifically the RAGE 2 looks like it could cut a max straight 7" width (90 degree) flat plate of 1/4" steel. The RAGE 3 looks like it could cut a little over a (90degree) 11" width. Lesser angles=lesser length cuts. From what I read it cuts straight true cuts; something you will absolutely NOT get on common abrasive metal cutting chop saws. Most machinists prefer the old reliable band saws; but they are usually a lot more expensive and alot bigger in overall size. A real potential negative I read is that the operator might have to "hold back" the chop saw a bit, as it wants to dig in faster than is normally safe. Some chop saw brands have some means of downward tension/pressure adjustments for their machines. If someone here already uses such I would be very interested in their assessment or notes. Meredith Lamb Hi all,

This seems like a very interesting fast cutting 14" circular cut-off or chop saw, as it supposedly cuts 1/4"
thick unhardened steel; which could be quite useful for those home hard to do projects like straight cutting the steel
plates for the neodymium pickup magnets and/or seismometer dampening.  There is some amazing online
videos of its use in action.  Amazing is a very common term I see from a variety of sellers on their various
web sites.

Specifically its the (blue label) steel cutting blade, but other blades can be used for other metals.
They also have another blue label blade for thin steel sheet metal.   The blades have 1" diameter
bores, which might fit other saws, but, the "other chop saw" motor speed needs to around 1500rpm
via gear reduction.

There is a web variety of sellers.  Even Sears (USA) sells "online only" the RAGE 2 chop saw; but unfortunately
without the best (blue label) steel blade, at a web low price of $279.00...you would need to get the "best" blue
label steel blade via other sellers on the web.   Sears also sells the RAGE 3 multipurpose compound sliding 10"
miter saw for $299.99; without again, the "best" (blue label) steel blade.  The common shown orange label blades seem
to be general multi-purpose metal cutting blades.   The RAGE 3 blade turns at 2500 rpm, but only lasts roughly
~1/4 the cuts of the RAGE 2; but might be more useful for other projects with all its more extensive setup options.

A good starting reference is below, and also shows a variety of metal blades:
http://www.evolutiononlineshop.com/store/index.cfm

Specifically the RAGE 2 looks like it could cut a max straight 7" width (90 degree) flat plate of 1/4" steel.   The
RAGE 3 looks like it could cut a little over a (90degree) 11" width.  Lesser angles=lesser length cuts.

From what I read it cuts straight true cuts; something you will absolutely NOT get on common abrasive metal
cutting chop saws.  Most machinists prefer the old reliable band saws; but they are usually a lot more expensive and
alot bigger in overall size.

A real potential negative I read is that the operator might have to "hold back" the chop saw a bit, as it wants
to dig in faster than is normally safe.  Some chop saw brands have some means of downward tension/pressure
adjustments for their machines.

If someone here already uses such I would be very interested in their assessment or notes.

Meredith Lamb

 


Subject: Re: Basic Programming Help desired? From: "Geoff" gmvoeth@........... Date: Sat, 10 May 2008 00:08:33 -0700 another programming language, he's wanting to run his data capture system on a low-spec machine (retired from other uses, I suspect). > > Kevin Nope, I used to run my program on a TRS Laptop With a 10MHz CPU (Z80 sound familiar ?) then some burglars stole that machine from my folks house which the insurance company replaced with Toshiba Satellite 205CDS and since the late 1990s (I think) I have been using that exclusively for seismic stuff. It has never been retired from anything I am aware of. Its RTC is terrible looses 1 second ( slow) every 4 hours or so Without a ring counter the WWV reception is so horrible Id have no decent calibration indicator for times. I can not compliment the Japanese in the calibration of their digital Quartz whatevers. Obviously this machine was never calibrated at operating temperatures. Although it keeps bad time it IS a rugged machine. In ruggedness it matches an old timex watch commercial. If I could recommend something to all manufacturers of electronic devices it would be to calibrate their quartz clocks properly and build everything within a faraday shield. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Basic Programming Help desired? From: Mike Price seapsn@........ Date: Sat, 10 May 2008 02:08:30 -0700 Regarding clocks in DOS (and all other OSes): The RTC is used to set the operating system clock only at boot. After that, the OS keeps time from its own timer driven by a periodic interrupt. Since interrupts can be blocked (e.g. by other interrupts), the OS must take special care to ensure an accurate time of day clock. DOS is notorious for failing to do this properly as are most versions of windows.One hack is to sync the OS clock with the RTC clock periodically (by calling the clock program from a script). Another is to run ntp (not possible on a singly threaded OS like DOS). If you need an accurate clock in DOS, there are routines available that can read the RTC clock directly and ignore the DOS clock. Regarding memory management in DOS. The PC can directly (easily) address only 640KB of memory. This was a HW restriction of the original PC, preserved in DOS despite CPU improvements. Extended memory can provide many megabytes, but memory accesses are slower since all accesses are indirect (an address register is loaded, then memory is accessed). The compiler takes care of memory management behind the scenes, but you'll get better performance if the code and data fit into the 640KB. Given a Pentium, Windows or Linux will implement a linear memory model and give better performance for large arrays (generally). Mike Geoff wrote: > another programming language, he's wanting to run his data capture > system on a low-spec machine (retired from other uses, I suspect). >> >> Kevin > > Nope, I used to run my program on a TRS Laptop With a > 10MHz CPU (Z80 sound familiar ?) then some burglars > stole that machine from my folks house which the > insurance company replaced with Toshiba Satellite > 205CDS and since the late 1990s (I think) I have been using that > exclusively for seismic stuff. > It has never been retired from anything I am aware of. > Its RTC is terrible looses 1 second ( slow) every > 4 hours or so Without a ring counter the WWV reception > is so horrible Id have no decent calibration indicator > for times. I can not compliment the Japanese > in the calibration of their digital Quartz whatevers. > Obviously this machine was never calibrated at operating > temperatures. Although it keeps bad time it IS a rugged machine. > In ruggedness it matches an old timex watch commercial. > If I could recommend something to all manufacturers > of electronic devices it would be to calibrate their > quartz clocks properly and build everything within a faraday shield. > > > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Unusual oscillations From: "Thomas Dick" dickthomas01@............. Date: Sat, 10 May 2008 08:24:04 -0500 Here in southern Indiana I have seen peaks in the area of .233Hz/4.338period for about twenty four hours. It is most pronounced on the E-W Lehman but even visible on the AS-1. Weather is quiet right now: little wind or fronts around -- even foggy. Has anyone else noticed this on your units? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Unusual oscillations From: ChrisAtUpw@....... Date: Sat, 10 May 2008 10:02:05 EDT In a message dated 2008/05/10, dickthomas01@............. writes: > Here in southern Indiana I have seen peaks in the area of > .233Hz/4.338period > for about twenty four hours. Hi Tom, Could these be Pacific Microseisms? They tend to be of shorter period than the Atlantic ones at about 6 seconds. Regards, Chris Chapman In a me= ssage dated 2008/05/10, dickthomas01@............. writes:

Here in southern Indiana I have= seen peaks in the area of .233Hz/4.338period
for about twenty four hours.


Hi Tom,

       Could these be Pacific Microseisms? The= y tend to be of shorter period than the Atlantic ones at about  6 secon= ds.

       Regards,

       Chris Chapman
Subject: Re: Unusual oscillations From: Larry Conklin lconklin@............ Date: Sat, 10 May 2008 10:05:44 -0400 Hi Thomas, Very probably, what you are seeing is microseisms. I have also been seeing this activity on my horizontal SG sensor for the last half a day or so, and they also are showing up strongly on the web site run by Lamont-Doherty Earth Observatory. My understanding is that the mechanism that produces these waves isn't completely understood, but that they are believed to be caused by ocean waves resulting from strong storms. Being able to see them is a good thing. It's a sign that your sensor is working well. Larry Conklin Liverpool, NY Thomas Dick wrote: > Here in southern Indiana I have seen peaks in the area of > .233Hz/4.338period for about twenty four hours. It is most pronounced on > the E-W Lehman but even visible on the AS-1. Weather is quiet right now: > little wind or fronts around -- even foggy. Has anyone else noticed this > on your units? > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: My lehman type sensor is ready From: "Gary Lindgren" gel@................. Date: Sat, 10 May 2008 11:40:21 -0700 Hello Jon, I'm in the process now in building my first Lehman, but here are my observations looking at the picture.=20 1. I agree with the comments of Chris. I highly recommend going to the Chapman magnet assembly for the sensor. Your coil seems too small in diameter and the highest flux area of the magnet is over the coil wires = that are in the direction of the magnet motion. In order for a voltage to be generated, you need to have the wires perpendicular to the magnet = motion. The problem with the small coil is that a voltage is generated from the = flux field broken on the far side of one polarity and then the opposite = polarity voltage is generated on the near side coil wires. The 2 voltages will = then offset each other. If you want to use your coil and magnet, then rotate = the magnet 90 degrees and then move the coil so that only one side of the = coil moves through the magnet flux field. You can purchase Neodymium magnets = from http://www.kjmagnetics.com/ They are very reasonable in cost. 2. The damping is probably not working at all. It looks as if you took = the speaker magnets and have either the north poles opposite or the south = poles opposite each other. If this is what you have then you have zero flux in = the middle where you have the damping plate. You must have a flux field set = up. That means that a north pole must face a south pole magnet. If you have opposite poles facing each other then you need to have a better return = flux path. Now you have only the 1/4 inch bolts are the return path. You = probably have magnetic flux spread all over. Think of your magnet assembly just = like an electrical circuit. The 1/4 inch bolts are just like a high = resistance path. Again go with the Chapman magnet assembly. Gary=20 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of J=F3n Fr=EDmann Sent: Friday, May 09, 2008 5:12 PM To: psn-l@.............. Subject: Re: My lehman type sensor is ready Hi all The lehman type sensor is up and running. However I have found one bad bug in it. Where the arm as attached to the arm where the mass is. I need to make it shorter (I think, at least so I can get it to hold the mass up properly) and attach it to the mass arm it self to hold it up. But the current attachment can't hold up the mass, that did destory the hoding inside of it. The second issue that I might have is that I am not sure if the damping is correct or not. Using Winquake FFT feature it appears that the seismomter has a natrual frequancy of around 1Hz but it goes down to 10 seconds. This is a second bug that I also need to fix somehow. As I am looking for up to 30 second period. I hope to fix the first bug on monday, I might also do some other modifactions to the sensor to make it more sensitive. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: My lehman type sensor is ready From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sat, 10 May 2008 19:45:25 +0000 Hi Gary 1. The magnets are an easy fix. If I turn the silver side on vs the dark side I get N/S configuration. However, part of the daming issue appears to be the arm that holds up the boom, it isn't holding it properly so the boom viprates more then it needs to when a signal passes trugh it. That issue is going to be fixed when I attach the arm directly with the boom. This is steel, not iron. But the base is made out of aluminum. 2. This issue is going to be resolved on 13th of May I hope. Then I am going to rotate the magnet 90 degress and put the coil on the boom. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Frequencies From: tchannel1@............ Date: Sat, 10 May 2008 16:07:27 -0600 Hi Folks, With some help from many of you, I understand how one loses = the signals LONGER than your sensor natural period. ie If you sensors = period is 10 seconds it will lose (attenuate) the longer frequencies at = a rate of 12 decibels per octave. I think I understand that part. =20 But want about the opposite, say the sensors is 10 second, how does it = lose or does it lose shorter frequencies, like 2, 4 or 6 seconds waves? My new Lehman is set at 20 seconds, will it pick up 1, 2, and 3 seconds = waves? Thanks, Ted
Hi Folks,  With some help from = many of you, I=20 understand how one loses the signals LONGER than your sensor natural=20 period.  ie  If you sensors period is 10 seconds it will = lose =20 (attenuate) the longer frequencies at a rate of 12 decibels per=20 octave.   I think I understand that part. 
 
But want about the opposite, say the = sensors is 10=20 second, how does it lose or does it lose shorter frequencies, like 2, 4 = or 6=20 seconds waves?
 
My new Lehman is set at 20 seconds, = will it pick up=20 1, 2, and 3 seconds waves?
 
Thanks, Ted
Subject: Re: Frequencies From: ChrisAtUpw@....... Date: Sat, 10 May 2008 19:16:43 EDT In a message dated 2008/05/10, tchannel1@............ writes: > But want about the opposite, say the sensors is 10 second, how does it lose > or does it lose shorter frequencies, like 2, 4 or 6 seconds waves? Hi Ted, The output should be flat with velocity from the natural period right up to the frequency set by the low pass filter on your amplifier. This is probably 10 Hz. Regards, Chris Chapman In a me= ssage dated 2008/05/10, tchannel1@............ writes:

But want about the opposite, sa= y the sensors is 10 second, how does it lose or does it lose shorter frequen= cies, like 2, 4 or 6 seconds waves?


Hi Ted,

       The output should be flat with velocity= from the natural period right up to the frequency set by the low pass filte= r on your amplifier. This is probably 10 Hz.

       Regards,

       Chris Chapman
Subject: Re: Unusual oscillations From: "Geoff" gmvoeth@........... Date: Sat, 10 May 2008 17:14:27 -0700 Yes, in my case it seems to preceed a weather front. ----- Original Message ----- From: "Thomas Dick" To: Sent: Saturday, May 10, 2008 6:24 AM Subject: Unusual oscillations > Here in southern Indiana I have seen peaks in the area of .233Hz/4.338period > for about twenty four hours. It is most pronounced on the E-W Lehman but > even visible on the AS-1. Weather is quiet right now: little wind or fronts > around -- even foggy. Has anyone else noticed this on your units? > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Frequencies From: "Geoff" gmvoeth@........... Date: Sat, 10 May 2008 17:18:06 -0700 Periods shorter meaning a higher freq should be ok with a 10 sec sensor or so I understand since the mass is at rest for freqs above resonance. The mass moves below resonance and thats why you loose sensitivity. Or so i understand. ----- Original Message ----- From: To: "psn" Sent: Saturday, May 10, 2008 3:07 PM Subject: Frequencies Hi Folks, With some help from many of you, I understand how one loses the signals LONGER than your sensor natural period. ie If you sensors period is 10 seconds it will lose (attenuate) the longer frequencies at a rate of 12 decibels per octave. I think I understand that part. But want about the opposite, say the sensors is 10 second, how does it lose or does it lose shorter frequencies, like 2, 4 or 6 seconds waves? My new Lehman is set at 20 seconds, will it pick up 1, 2, and 3 seconds waves? Thanks, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Unusual oscillations From: "Thomas Dick" dickthomas01@............. Date: Sun, 11 May 2008 10:22:39 -0500 I guess Geoff is right. The intensity has increased. I have two lows passing; one to the north and the other to the south -- even tornadoes to my south. Local winds sustained above 10 mpn ... gusting to 25 mph with occasional gusts above 35 mph. Electricity was off briefly too. ----- Original Message ----- From: "Geoff" To: Sent: Saturday, May 10, 2008 7:14 PM Subject: Re: Unusual oscillations > Yes, in my case it seems to preceed a weather front. > > ----- Original Message ----- > From: "Thomas Dick" > To: > Sent: Saturday, May 10, 2008 6:24 AM > Subject: Unusual oscillations > > >> Here in southern Indiana I have seen peaks in the area of >> .233Hz/4.338period for about twenty four hours. It is most pronounced on >> the E-W Lehman but even visible on the AS-1. Weather is quiet right now: >> little wind or fronts around -- even foggy. Has anyone else noticed this >> on your units? __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of >> the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: China Quake From: ian ian@........... Date: Mon, 12 May 2008 08:36:19 +0100 Hi, getting enormous signals from the China quake here in Scotland. See http://www.iasmith.com . Ian __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: China Quake From: ChrisAtUpw@....... Date: Mon, 12 May 2008 08:19:34 EDT In a message dated 2008/05/12, ian@........... writes: > getting enormous signals from the China quake here in Scotland. See > http://www.iasmith.com HI Ian, Likewise! I get a time out error when I try to call your website as listed above. Regards, Chris Chapman In a me= ssage dated 2008/05/12, ian@........... writes:

getting enormous signals from t= he China quake here in Scotland.  See
http://www.iasmith.com


HI Ian,

       Likewise!

       I get a time out error when I try to ca= ll your website as listed above.

       Regards,

       Chris Chapman
Subject: Re: China Quake From: ian ian@........... Date: Mon, 12 May 2008 13:24:33 +0100 Hi, I can still get my web page to respond from here. It's hosted in the states... It's also on the psn site: http://www.webtronics.com/cgi-dos/makegif.exe?/quakes/0805/080512.063616.hd1.psn though the P & S markers have gone for a walk! Ian ChrisAtUpw@....... wrote: > In a message dated 2008/05/12, ian@........... writes: > >> getting enormous signals from the China quake here in Scotland. See >> http://www.iasmith.com > > > HI Ian, > > Likewise! > > I get a time out error when I try to call your website as > listed above. > > Regards, > > Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: China Quake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Mon, 12 May 2008 12:33:41 +0000 Hi all I did record the China earthquake on all of my sensors. The signal did appear clearly here in Iceland. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Map of the tectonic plates From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Mon, 12 May 2008 22:53:38 +0000 Hi all Here is a map with the tectonic plates of the earth. Along with good details of other major fault lines. http://www.globalchange.umich.edu/globalchange1/current/lectures/evolving_e= arth/tectonic_map.jpg Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: China Quake From: "Geoff" gmvoeth@........... Date: Mon, 12 May 2008 16:12:21 -0700 Roger That, here's the picture from [GVA] SPZ http://gmvoeth.home.mchsi.com/gva_20080512_06422611_UTC.psn.gif ----- Original Message ----- From: "ian" To: Sent: Monday, May 12, 2008 12:36 AM Subject: China Quake > Hi, > > getting enormous signals from the China quake here in Scotland. See > http://www.iasmith.com . > > Ian > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Correction to old message From: "Geoff" gmvoeth@........... Date: Thu, 15 May 2008 09:51:26 -0700 "Nope, I used to run my program on a TRS Laptop With a 10MHz CPU (Z80 sound familiar ?) then some burglars stole that machine from my folks house which the insurance company replaced with Toshiba Satellite 205CDS and since the late 1990s (I think) I have been using that exclusively for seismic stuff." NOT Z80 but rather VIC-20. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Strong motion records in China From: "Christos Papaioannou" chpapai@........ Date: Thu, 15 May 2008 20:53:06 +0300 Hello to everybody, Does anyone of you know anything about recorded accelerations after the big earthquake of May 14 in China? Is there any site IN ENGLISH where someone may find information on strong motion records in China? Thank you in advance Christos A. PAPAIOANNOU CONFIDENTIALITY AND DISCLAIMER NOTICE This e-mail is intended only for the addressee named above. It must not be read, copied, disclosed or used by any person other than the addressee(s) named above. If you received this e_mail in error, please return it to the sender. Any views or opinions presented are solely those of the sender and do not necessarily represent those of I.T.S.A.K. unless otherwise specifically stated. As Internet communications are not secure, I do not accept legal responsibility for the contents of this message nor responsibility for any change made to this message after the original sender sent it. I advise you to carry out your own virus check before opening any attachment, as I cannot accept liability for any damage sustained as a result of any software viruses. \\\|/// \\ - - // ( @ @ ) *-------oOOOo-(_)-oOOOo----------------------------------------------* * * * /\ * * / \ /\ /\ * * ___/\ / \ / \/\ / \/\/\_______ ITSAK * * \/ \ / \/ P.O. Box 53, Foinikas * * \/ GR-55102 Thessaloniki * * GREECE * * * * Christos A. PAPAIOANNOU tel. (+).30.2310476081 -84 * * Seismologist Ph.D. extension 127 * * fax (+).30.2310476085 * * cellular (+).30.6977217868 * * * * e_mail : chpapai@........ * *------------------Ooooo---------------------------------------------* ooooO ( ) ( ) ) / \ ( (_/ \_)
        Hello to=20 everybody,

        Does anyone = of you=20 know anything about recorded accelerations after the big
earthquake of = May 14 in=20 China?
        Is there any site IN = ENGLISH=20 where someone may find information on strong
motion = records in=20 China?
 
        Thank you in advance
         Christos  A. = PAPAIOANNOU


 CONFIDENTIALITY AND DISCLAIMER=20 NOTICE
 This  e-mail is intended only for the addressee = named=20 above.
 It must not be read, copied, disclosed or used by any = person=20 other
than  the=20 addressee(s) named above. If you received this e_mail  in
error, = please=20 return it to the sender.
 Any views or opinions presented are = solely=20 those of the sender and
do not necessarily represent those of =20 I.T.S.A.K. unless  otherwise
specifically stated.
 As = Internet=20 communications are not  secure,  I do not accept=20 legal
responsibility for the contents of  this message nor=20 responsibility
for any  change made to this message after the = original=20 sender sent
it.
 I advise you to carry out your own virus = check=20 before  opening any
attachment, as I cannot accept  = liability =20 for any damage sustained
as a result of any software=20 viruses.


         = ;  =20 \\\|///
          = \\  -=20 -  = //
          =20 (  @ @ =20 )
*-------oOOOo-(_)-oOOOo---------------------------------------------= -*
*           =             &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;       =20 *
*         =20 /\            = ;            =             &= nbsp;           &n= bsp;      =20 *
*         / =20 \      /\     =20 /\            = ;            =             &= nbsp; =20 *
* ___/\  /    \    /  = \/\ =20 /  \/\/\_______=20 ITSAK           &n= bsp;        =20 *
*      \/      = \ =20 /     =20 \/            = ;   =20 P.O. Box 53, Foinikas    =20 *
*           &= nbsp;  =20 \/            = ;            = =20 GR-55102 Thessaloniki    =20 *
*           &= nbsp;           &n= bsp;           &nb= sp;     =20 GREECE           &= nbsp;       =20 *
*           &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;            = ;       =20 *
*    Christos A.=20 PAPAIOANNOU          &n= bsp;  =20 tel. (+).30.2310476081 -84 *
*    Seismologist=20 Ph.D.           &n= bsp;           &nb= sp;  =20 extension 127     =20 *
*           &= nbsp;           &n= bsp;           &nb= sp;    =20 fax  (+).30.2310476085    =20 *
*           &= nbsp;           &n= bsp;           &nb= sp;    =20 cellular (+).30.6977217868=20 *
*           &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;            = ;       =20 *
*           &= nbsp;           &n= bsp;           &nb= sp;    =20 e_mail : chpapai@........ =20 *
*------------------Ooooo--------------------------------------------= -*
         =20 ooooO    (   =20 )
          = (   =20 )    ) =20 /
           = \ =20 (    =20 (_/
           = =20 \_)

Subject: Round external coils and stacked internal magnets From: "meredith lamb" paleoartifact@......... Date: Fri, 16 May 2008 11:47:57 -0600 Hi all, Am getting to the (shall we say a unqualified) opinion that with a choice of round or square/rectangular coils with a magnet, that it seems like the round coil approach is the more efficient route to take. It just simply uses all the coil and not just a couple selected sides mainly. Theres obviously no heavy problem to making a round coil; versus the more construction work with a square or rectangular coil. The route you take with the round coil size/shape with the magnet/s can be quite different than most now use. Having multi or multiple round (or ring) magnets stacked attracting, with the coil on the outside centered seems to be a sensitive and quick approach. One magnet can work, but with 2 or more, it will increase the sensitivity, and, the coil will be normally centered down the length of the magnet stack. The magnets are still mounted on a metal plate. It still works normally; i.e., movement in one direction will still be + or - throughout its continued movement in that direction; and vice versa + or - signal for the other direction. For home brew seismometers with a heavy mechanical boom/coil drift problem; this approach would seem to be the best ideal design answer. Although I've not actually done it, one could also put a iron can around and slightly away from such a coil/magnet assembly, and slightly increase the sensitivity, while also providing a measure of limiting some magnetic or electro magnetic induction "noise" pickup and air or thermal influence also. Tight and limited movement magnet coil assemblys are interesting to be sure; but what the heck; your amplifier gain controls should easily take up any slack. Take care, Meredith Lamb Hi all,

Am getting to the (shall we say a unqualified) opinion that with a choice of round or square/rectangular coils
with a magnet, that it seems like the round coil approach is the more efficient route to take.  It just simply
uses all the coil and not just a couple selected sides mainly.  Theres obviously no heavy
problem to making a round coil; versus the more construction work with a square or rectangular coil. 

The route you take with the round coil size/shape with the magnet/s can be quite different than most now use.

Having multi or multiple round (or ring) magnets stacked attracting, with the coil on the outside centered
seems to be a sensitive and quick approach.   One magnet can work, but with 2 or more, it will increase
the sensitivity, and, the coil will be normally centered down the length of the magnet stack.  The magnets
are still mounted on a metal plate.  It still works normally; i.e., movement in one direction will still be + or -
throughout its continued movement in that direction; and vice versa + or - signal for the other direction.

For home brew seismometers with a heavy mechanical boom/coil drift problem; this approach would seem
to be the best ideal design answer.

Although I've not actually done it, one could also put a iron can around and slightly away from
such a coil/magnet assembly, and slightly increase the sensitivity, while also providing a measure
of limiting some magnetic or electro magnetic induction "noise" pickup and air or thermal influence also.

Tight and limited movement magnet coil assemblys are interesting to be sure; but what the heck; your
amplifier gain controls should easily take up any slack.

Take care, Meredith Lamb

Subject: Re: Round external coils and stacked internal magnets From: ian ian@........... Date: Fri, 16 May 2008 19:25:11 +0100 Hi, I too have a heretical arrangement: Round coil mounted on the ground and a single column horizontal stack of 7 10mm cubed neodymium magnets attached to the end of the pendulum, perpendicular to it, which moves back and forth inside and along the internal axis of the coil. This non-optimum arrangement does simplify the mechanical design in that there are no signal wires coming off the pendulum. It would be interesting to hear how much is lost by this non-optimum arrangement. Is it worth the modification? Ian meredith lamb wrote: > Hi all, > > Am getting to the (shall we say a unqualified) opinion that with a > choice of round or square/rectangular coils > with a magnet, that it seems like the round coil approach is the more > efficient route to take. It just simply > uses all the coil and not just a couple selected sides mainly. Theres > obviously no heavy > problem to making a round coil; versus the more construction work with > a square or rectangular coil. > > The route you take with the round coil size/shape with the magnet/s > can be quite different than most now use. > > Having multi or multiple round (or ring) magnets stacked attracting, > with the coil on the outside centered > seems to be a sensitive and quick approach. One magnet can work, but > with 2 or more, it will increase > the sensitivity, and, the coil will be normally centered down the > length of the magnet stack. The magnets > are still mounted on a metal plate. It still works normally; i.e., > movement in one direction will still be + or - > throughout its continued movement in that direction; and vice versa + > or - signal for the other direction. > > For home brew seismometers with a heavy mechanical boom/coil drift > problem; this approach would seem > to be the best ideal design answer. > > Although I've not actually done it, one could also put a iron can > around and slightly away from > such a coil/magnet assembly, and slightly increase the sensitivity, > while also providing a measure > of limiting some magnetic or electro magnetic induction "noise" pickup > and air or thermal influence also. > > Tight and limited movement magnet coil assemblys are interesting to be > sure; but what the heck; your > amplifier gain controls should easily take up any slack. > > Take care, Meredith Lamb > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Round external coils and stacked internal magnets From: ChrisAtUpw@....... Date: Fri, 16 May 2008 16:56:48 EDT In a message dated 2008/05/16, paleoartifact@......... writes: > Am getting to the (shall we say a unqualified) opinion that with a choice > of round or square / rectangular coils with a magnet, that it seems like the > round coil approach is the more efficient route to take. Hi Meredith, If you want an accurately linear output from a Lehman, while allowing for the large sensor drifts that you always get, you definitely need to use a quad arrangement of square NdFeB magnets and a rectangular coil. Round coils will DEFINITELY NOT give you a constant sensitivity over the drift range of a Lehman sensor. If you are using a vertical pendulum, you can use a quad arrangement of rectangular magnets with the width of a magnet ~ the ID of the coil. Alternatively, you can make up a magnet block and attach it to the pendulum to form part or all of the mass. But you will then still get a small sensitivity to environmental magnetic fields. You make the ID of the actual windings about 3/4 of the width of a magnet and the internal length about 1/5 greater. This allows for some position error either as the coil swings in an arc or for any setup position error. The flux change for a given magnet movement is then CONSTANT over maybe 3/4" drift with 1" square magnets. Mount the magnets on 1/4" thick mild steel backing plates held apart with zinc plated mild steel bolts. You need to give the mild steel some etch primer and a coat of anti rust paint. I use Hermetite. You paint the whole surface of the plates, then leave them a couple of days for the paint to harden. I make up a cardboard cut-out, clamp it to the plate and slide the magnets into position over the cardboard. This is 'the easy way to do it'! One advantage of this construction is that you only need maybe 2,500 turns on you coil. The voltage output is maybe 10x what you get with a U Alnico magnet. This arrangement is shown on the drawings at http://www.jclahr.com/science/psn/chapman/lehman/index.html It is quite easy to make a rectangular coil former out of thin glass circuit board / sheet glass fibre. DigiKey sell both. You can either use the construction shown, or you can make a wood / plastic inner coil former and screw / glue it between two sheets to form the ends of the coil. I suggest winding it using a bolt through the centre gripped by a hand drill, held in a vice. Use some fine plastic tube to guide the wire onto the coil. Spray cans usually have suitable tube if you open one up. I use two part Acrylic glue - Devcon Plastic Welder or similar. I defiitely avoid using 'coil dope' - I find that I get too many shorted turns. You can use coil dope OK if you very carefully wind a single layer of wire at a time and then use tissue paper to interleave the winding layers. With luck, you are only going to ever make one coil per seismometer, so it REALL IS worth a bit of extra effort to get the best out of your instrument. Regards, Chris Chapman In a me= ssage dated 2008/05/16, paleoartifact@......... writes:

Am getting to the (shall we say= a unqualified) opinion that with a choice of round or square / rectangular=20= coils with a magnet, that it seems like the round coil approach is the more=20= efficient route to take.


Hi Meredith,

       If you want an accurately linear output= from a Lehman, while allowing for the large sensor drifts that you always g= et, you definitely need to use a quad arrangement of square NdFeB magnets an= d a rectangular coil.

       Round coils will DEFINITELY NOT give yo= u a constant sensitivity over the drift range of a Lehman sensor.
       If you are using a vertical pendulum, y= ou can use a quad arrangement of rectangular magnets with the width of a mag= net ~ the ID of the coil. Alternatively, you can make up a magnet block and=20= attach it to the pendulum to form part or all of the mass. But you will then= still get a small sensitivity to environmental magnetic fields.

       You make the ID of the actual windings=20= about 3/4 of the width of a magnet and the internal length about 1/5 greater= .. This allows for some position error either as the coil swings in an arc or= for any setup position error.  The flux change for a given magnet move= ment is then CONSTANT over maybe 3/4" drift with 1" square magnets.

       Mount the magnets on 1/4" thick mild st= eel backing plates held apart with zinc plated mild steel bolts. You need to= give the mild steel some etch primer and a coat of anti rust paint. I use H= ermetite. You paint the whole surface of the plates, then leave them a coupl= e of days for the paint to harden. I make up a cardboard cut-out, clamp it t= o the plate and slide the magnets into position over the cardboard. This is=20= 'the easy way to do it'!

       One advantage of this construction is t= hat you only need maybe 2,500 turns on you coil. The voltage output is maybe= 10x what you get with a U Alnico magnet.

       This arrangement is shown on the drawin= gs at http://www.jclahr.com/science/psn/chapman/lehman/index.html

       It is quite easy to make a rectangular=20= coil former out of thin glass circuit board / sheet glass fibre. DigiKey sel= l both. You can either use the construction shown, or you can make a wood /=20= plastic inner coil former and screw / glue it between two sheets to form the= ends of the coil. I suggest winding it using a bolt through the centre grip= ped by a hand drill, held in a vice. Use some fine plastic tube to guide the= wire onto the coil. Spray cans usually have suitable tube if you open one u= p. I use two part Acrylic glue - Devcon Plastic Welder or similar.

       I defiitely avoid using 'coil dope' - I= find that I get too many shorted turns. You can use coil dope OK if you ver= y carefully wind a single layer of wire at a time and then use tissue paper=20= to interleave the winding layers.

       With luck, you are only going to ever m= ake one coil per seismometer, so it REALL IS worth a bit of extra effort to=20= get the best out of your instrument.

       Regards,

       Chris Chapman
Subject: Oil Furnace Nozzle Connection From: "Gary Lindgren" gel@................. Date: Fri, 16 May 2008 15:13:36 -0700 The typical Lehman uses an oil furnace nozzle as a connection point for the upper end of the music wire that is attached to the boom. What method is used to modify the nozzle in order to fasten the wire. What modifications are made. Thank you Gary Lindgren Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com cymonsplace.blogspot.com

The typical Lehman uses an oil furnace nozzle as a connection point for the upper end of the music wire that is attached to = the boom. What method is used to modify the nozzle in order to fasten the = wire. What modifications are made.

Thank you

Gary Lindgren

 

 

 

 

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

 

650-326-0655<= /span>

 

www.blue-eagle-technologies.com

cymonsplace.blogspot.com 

 

Subject: Re: Oil Furnace Nozzle Connection From: ChrisAtUpw@....... Date: Fri, 16 May 2008 19:45:05 EDT In a message dated 2008/05/16, gel@................. writes: > The typical Lehman uses an oil furnace nozzle as a connection point for the > upper end of the music wire that is attached to the boom. What method is > used to modify the nozzle in order to fasten the wire. What modifications are > made. Hi Gary, The idea was to choose a music wire ~ the same diameter as the nozzle bore, but I don't know what that is. http://www.daddario.com/ list most of the music wires that are made. It is worthwhile getting wire which is nickel plated to minimise any rust problems. You might find it easier to clamp the wire between two washers? You do need to drill a hole for the wire through the centre of the clamp bolt. On system that I have used successfully is to mount the bottom SS ball bearing in the end of 3/8" bolt. I drill out a cone in the end of the bolt with a centre drill and stick the ball in place. Then I mount the bolt through the upright column with nuts and washers on both sides. This allows me to alter the horizontal position of the ball. I use a SS scalpel blade on the end of the arm as the hard counterface. The top suspension is another 3/8" bolt similarly fitted to the upright column. I file off about 3/8" of the threaded end of the bolt, about half way through and file just the thread off the other side of the bolt. I then drill a 1/8" hold in the centre of the flat and use an 1/8" bolt and two washers to clamp the music wire. SS bearings are stocked by www.smallparts.com. I stroingly advise against trying to use a knife edge or a point suspension. Ball on a plane and crossed cylinder suspensions both give much better results. These two adjustment bolts allow me to set up the seismometer so that it has a period of about 10 seconds when the baseplate is level. I then trim the period by raising the end of the base. Have a look at the school seismometers at http://www.jclahr.com/science/psn/chapman/school/MKII/index.html and at http://www.bgs.ac.uk/education/school_seismology/seismometer.html The first one used eccentric washers to set the position of the top suspension. Make the seismometer as one unit with a long base. This is far easier to set up and to adjust than the types described on psn. I have used 3" x 1" U channl Aluminum for the frame and cross piece, with 1/8" thick triangular corner plates at the main joint. I use SS bolts in contact with the Al. Regards, Chris Chapman In a me= ssage dated 2008/05/16, gel@................. writes:

The typical Lehman uses an oil=20= furnace nozzle as a connection point for the upper end of the music wire tha= t is attached to the boom. What method is used to modify the nozzle in order= to fasten the wire. What modifications are made.


Hi Gary,

       The idea was to choose a music wire ~ t= he same diameter as the nozzle bore, but I don't know what that is. http://w= ww.daddario.com/ list most of the music wires that are made. It is worthwhil= e getting wire which is nickel plated to minimise any rust problems.

       You might find it easier to clamp the w= ire between two washers? You do need to drill a hole for the wire through th= e centre of the clamp bolt.

       On system that I have used successfully= is to mount the bottom SS ball bearing in the end of 3/8" bolt. I drill out= a cone in the end of the bolt with a centre drill and stick the ball in pla= ce. Then I mount the bolt through the upright column with nuts and washers o= n both sides. This allows me to alter the horizontal position of the ball. I= use a SS scalpel blade on the end of the arm as the hard counterface.
       The top suspension is another 3/8" bolt= similarly fitted to the upright column. I file off about 3/8" of the thread= ed end of the bolt, about half way through and file just the thread off the=20= other side of the bolt. I then drill a 1/8" hold in the centre of the flat a= nd use an 1/8" bolt and two washers to clamp the music wire.
       SS bearings are stocked by www.smallpar= ts.com.
       I stroingly advise against trying to us= e a knife edge or a point suspension. Ball on a plane and crossed cylinder s= uspensions both give much better results.
       These two adjustment bolts allow me to=20= set up the seismometer so that it has a period of about 10 seconds when the=20= baseplate is level. I then trim the period by raising the end of the base.        Have a look at the school seismometers=20= at http://www.jclahr.com/science/psn/chapman/school/MKII/index.html and at <= BR> http://www.bgs.ac.uk/education/school_seismology/seismometer.html  = ; 
       The first one used eccentric washers to= set the position of the top suspension.
       Make the seismometer as one unit with a= long base. This is far easier to set up and to adjust than the types descri= bed on psn.
       I have used 3" x 1" U channl Aluminum f= or the frame and cross piece, with 1/8" thick triangular corner plates at th= e main joint. I use SS bolts in contact with the Al.

       Regards,

       Chris Chapman
Subject: RE: Oil Furnace Nozzle Connection From: "Gary Lindgren" gel@................. Date: Fri, 16 May 2008 17:40:19 -0700 Chris, Thank you for the fine pictures. Yes, I throw out the idea of using the oil furnace nozzle. For the ball bearing I'm going to use a ceramic ball bearing. It is extremely hard and then I will use 2 crossed hardened dowel pins on the vertical post. Gary Lindgren From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of ChrisAtUpw@....... Sent: Friday, May 16, 2008 4:45 PM To: psn-l@.............. Subject: Re: Oil Furnace Nozzle Connection In a message dated 2008/05/16, gel@................. writes: The typical Lehman uses an oil furnace nozzle as a connection point for the upper end of the music wire that is attached to the boom. What method is used to modify the nozzle in order to fasten the wire. What modifications are made. Hi Gary, The idea was to choose a music wire ~ the same diameter as the nozzle bore, but I don't know what that is. http://www.daddario.com/ list most of the music wires that are made. It is worthwhile getting wire which is nickel plated to minimise any rust problems. You might find it easier to clamp the wire between two washers? You do need to drill a hole for the wire through the centre of the clamp bolt. On system that I have used successfully is to mount the bottom SS ball bearing in the end of 3/8" bolt. I drill out a cone in the end of the bolt with a centre drill and stick the ball in place. Then I mount the bolt through the upright column with nuts and washers on both sides. This allows me to alter the horizontal position of the ball. I use a SS scalpel blade on the end of the arm as the hard counterface. The top suspension is another 3/8" bolt similarly fitted to the upright column. I file off about 3/8" of the threaded end of the bolt, about half way through and file just the thread off the other side of the bolt. I then drill a 1/8" hold in the centre of the flat and use an 1/8" bolt and two washers to clamp the music wire. SS bearings are stocked by www.smallparts.com. I stroingly advise against trying to use a knife edge or a point suspension. Ball on a plane and crossed cylinder suspensions both give much better results. These two adjustment bolts allow me to set up the seismometer so that it has a period of about 10 seconds when the baseplate is level. I then trim the period by raising the end of the base. Have a look at the school seismometers at http://www.jclahr.com/science/psn/chapman/school/MKII/index.html and at http://www.bgs.ac.uk/education/school_seismology/seismometer.html The first one used eccentric washers to set the position of the top suspension. Make the seismometer as one unit with a long base. This is far easier to set up and to adjust than the types described on psn. I have used 3" x 1" U channl Aluminum for the frame and cross piece, with 1/8" thick triangular corner plates at the main joint. I use SS bolts in contact with the Al. Regards, Chris Chapman

Chris,

Thank you for the fine pictures. Yes, I throw out the = idea of using the oil furnace nozzle. For the ball bearing I’m going to = use a ceramic ball bearing. It is extremely hard and then I will use 2 crossed = hardened dowel pins on the vertical post.

Gary Lindgren

 

 

 

 

 

From:= = psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of = ChrisAtUpw@.......
Sent: Friday, May 16, 2008 4:45 PM
To: psn-l@..............
Subject: Re: Oil Furnace Nozzle Connection

 

In a message dated 2008/05/16, gel@................. writes:


The typical Lehman uses an oil furnace nozzle as a connection point for the = upper end of the music wire that is attached to the boom. What method is used = to modify the nozzle in order to fasten the wire. What modifications are = made.



Hi Gary,

       The idea was to choose a music wire = ~ the same diameter as the nozzle bore, but I don't know what that is. http://www.daddario.com/ list most of the music wires that are made. It = is worthwhile getting wire which is nickel plated to minimise any rust = problems.

       You might find it easier to clamp = the wire between two washers? You do need to drill a hole for the wire through = the centre of the clamp bolt.

       On system that I have used = successfully is to mount the bottom SS ball bearing in the end of 3/8" bolt. I = drill out a cone in the end of the bolt with a centre drill and stick the ball in = place. Then I mount the bolt through the upright column with nuts and washers = on both sides. This allows me to alter the horizontal position of the ball. I = use a SS scalpel blade on the end of the arm as the hard counterface.
       The top suspension is another = 3/8" bolt similarly fitted to the upright column. I file off about 3/8" = of the threaded end of the bolt, about half way through and file just the = thread off the other side of the bolt. I then drill a 1/8" hold in the centre = of the flat and use an 1/8" bolt and two washers to clamp the music wire. =
       SS bearings are stocked by www.smallparts.com.
       I stroingly advise against trying = to use a knife edge or a point suspension. Ball on a plane and crossed cylinder = suspensions both give much better results.
       These two adjustment bolts allow me = to set up the seismometer so that it has a period of about 10 seconds when the baseplate is level. I then trim the period by raising the end of the = base.
       Have a look at the school = seismometers at http://www.jclahr.com/science/psn/chapman/school/MKII/index.html and at =
http://www.bgs.ac.uk/education/school_seismology/seismometer.html &n= bsp; 
       The first one used eccentric = washers to set the position of the top suspension.
       Make the seismometer as one unit = with a long base. This is far easier to set up and to adjust than the types = described on psn.
       I have used 3" x 1" U = channl Aluminum for the frame and cross piece, with 1/8" thick triangular = corner plates at the main joint. I use SS bolts in contact with the Al.

       Regards,

       Chris Chapman

Subject: Re: Oil Furnace Nozzle Connection From: ChrisAtUpw@....... Date: Fri, 16 May 2008 22:55:48 EDT In a message dated 2008/05/17, gel@................. writes: > I will use 2 crossed hardened dowel pins on the vertical post. > Gary Lindgren Hi Gary, Unless they are carbide or stainless steel they won't last long. You get surface corrosion actively promoted between dry rolling surfaces. And I would advise against using oil. It doesn't last long and the bearings tend to slip out of position. You can get polished stainless type 415 shoulder bolts from McMaster Carr. http://www.mcmaster.com/ I think that John Cole uses these. Regards, Chris Chapman In a me= ssage dated 2008/05/17, gel@................. writes:

I will use 2 crossed hardened d= owel pins on the vertical post.
Gary Lindgren


Hi Gary,

       Unless they are carbide or stainless st= eel they won't last long. You get surface corrosion actively promoted betwee= n dry rolling surfaces. And I would advise against using oil. It doesn't las= t long and the bearings tend to slip out of position.

        You can get polished stainless ty= pe 415 shoulder bolts from McMaster Carr. http://www.mcmaster.com/ I think t= hat John Cole uses these.

      
Regards,

       Chris Chapman

Subject: Re: China Quake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sat, 17 May 2008 04:18:45 +0000 Hi all Here are two articals on the China earthquake. http://news.nationalgeographic.com/news/2008/05/080516-earthquake-predicted= ..html http://news.nationalgeographic.com/news/2008/05/080515-AP-china-quake.html Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Round external coils and stacked internal magnets From: "meredith lamb" paleoartifact@......... Date: Fri, 16 May 2008 22:21:56 -0600 Hi Chris and all, Thanks Chris for the extensive reply below. Actually my impression with the stacked magnets came from trying to utilize a old surplus Texas Instruments rectangular coil form, and at the time, the stacked magnets approach seemed quite impressive at the time via a table top and voltmeter experiment. The problem with the coil is it has relatively thin walls, and I'am not so sure that a quad (4) magnet setup is the best or only approach. Its possible to use 3 magnets and essentially get a similar "quad" (4 pole) arrangement, where the fields go through the sides of the coil walls. The coil form shape is quite similar to transformer coil forms, and in a sense there maybe 2 ways to use magnets with them. Esterline-Angus also made similar coils back in the 1950's, of which I also have some of those. I put up a quick web page with 2 photos on the TI coil; along with my "notes/ramblings" related to such: http://seismometer.googlepages.com/tirectiwritercoilconversion Take care, Meredith Lamb On Fri, May 16, 2008 at 2:56 PM, wrote: > In a message dated 2008/05/16, paleoartifact@......... writes: > > Am getting to the (shall we say a unqualified) opinion that with a choice > of round or square / rectangular coils with a magnet, that it seems like the > round coil approach is the more efficient route to take. > > > > Hi Meredith, > > If you want an accurately linear output from a Lehman, while > allowing for the large sensor drifts that you always get, you definitely > need to use a quad arrangement of square NdFeB magnets and a rectangular > coil. > > Round coils will DEFINITELY NOT give you a constant sensitivity over > the drift range of a Lehman sensor. > If you are using a vertical pendulum, you can use a quad arrangement > of rectangular magnets with the width of a magnet ~ the ID of the coil. > Alternatively, you can make up a magnet block and attach it to the pendulum > to form part or all of the mass. But you will then still get a small > sensitivity to environmental magnetic fields. > > You make the ID of the actual windings about 3/4 of the width of a > magnet and the internal length about 1/5 greater. This allows for some > position error either as the coil swings in an arc or for any setup position > error. The flux change for a given magnet movement is then CONSTANT over > maybe 3/4" drift with 1" square magnets. > > Mount the magnets on 1/4" thick mild steel backing plates held apart > with zinc plated mild steel bolts. You need to give the mild steel some etch > primer and a coat of anti rust paint. I use Hermetite. You paint the whole > surface of the plates, then leave them a couple of days for the paint to > harden. I make up a cardboard cut-out, clamp it to the plate and slide the > magnets into position over the cardboard. This is 'the easy way to do it'! > > One advantage of this construction is that you only need maybe 2,500 > turns on you coil. The voltage output is maybe 10x what you get with a U > Alnico magnet. > > This arrangement is shown on the drawings at > http://www.jclahr.com/science/psn/chapman/lehman/index.html > > It is quite easy to make a rectangular coil former out of thin glass > circuit board / sheet glass fibre. DigiKey sell both. You can either use the > construction shown, or you can make a wood / plastic inner coil former and > screw / glue it between two sheets to form the ends of the coil. I suggest > winding it using a bolt through the centre gripped by a hand drill, held in > a vice. Use some fine plastic tube to guide the wire onto the coil. Spray > cans usually have suitable tube if you open one up. I use two part Acrylic > glue - Devcon Plastic Welder or similar. > > I defiitely avoid using 'coil dope' - I find that I get too many > shorted turns. You can use coil dope OK if you very carefully wind a single > layer of wire at a time and then use tissue paper to interleave the winding > layers. > > With luck, you are only going to ever make one coil per seismometer, > so it REALL IS worth a bit of extra effort to get the best out of your > instrument. > > Regards, > > Chris Chapman Hi Chris and all,

Thanks Chris for the extensive reply below.  Actually my impression with the stacked magnets came from
trying to utilize a old surplus Texas Instruments rectangular coil form, and at the time, the stacked
magnets approach seemed quite impressive at the time via a table top and voltmeter experiment.

The problem with the coil is it has relatively thin walls, and I'am not so sure that a quad (4) magnet
setup is the best or only approach.  Its possible to use 3 magnets and essentially get a similar "quad" (4 pole)
arrangement, where the fields go through the sides of the coil walls.

The coil form shape is quite similar to transformer coil forms, and in a sense there maybe 2 ways to
use magnets with them.  Esterline-Angus also made similar coils back in the 1950's, of which
I also have some of those.

I put up a quick web page with 2 photos on the TI coil; along with my "notes/ramblings" related to such:

http://seismometer.googlepages.com/tirectiwritercoilconversion

Take care, Meredith Lamb


On Fri, May 16, 2008 at 2:56 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/05/16, paleoartifact@......... writes:

Am getting to the (shall we say a unqualified) opinion that with a choice of round or square / rectangular coils with a magnet, that it seems like the round coil approach is the more efficient route to take.


Hi Meredith,

       If you want an accurately linear output from a Lehman, while allowing for the large sensor drifts that you always get, you definitely need to use a quad arrangement of square NdFeB magnets and a rectangular coil.

       Round coils will DEFINITELY NOT give you a constant sensitivity over the drift range of a Lehman sensor.
       If you are using a vertical pendulum, you can use a quad arrangement of rectangular magnets with the width of a magnet ~ the ID of the coil. Alternatively, you can make up a magnet block and attach it to the pendulum to form part or all of the mass. But you will then still get a small sensitivity to environmental magnetic fields.

       You make the ID of the actual windings about 3/4 of the width of a magnet and the internal length about 1/5 greater. This allows for some position error either as the coil swings in an arc or for any setup position error.  The flux change for a given magnet movement is then CONSTANT over maybe 3/4" drift with 1" square magnets.

       Mount the magnets on 1/4" thick mild steel backing plates held apart with zinc plated mild steel bolts. You need to give the mild steel some etch primer and a coat of anti rust paint. I use Hermetite. You paint the whole surface of the plates, then leave them a couple of days for the paint to harden. I make up a cardboard cut-out, clamp it to the plate and slide the magnets into position over the cardboard. This is 'the easy way to do it'!

       One advantage of this construction is that you only need maybe 2,500 turns on you coil. The voltage output is maybe 10x what you get with a U Alnico magnet.

       This arrangement is shown on the drawings at http://www.jclahr.com/science/psn/chapman/lehman/index.html

       It is quite easy to make a rectangular coil former out of thin glass circuit board / sheet glass fibre. DigiKey sell both. You can either use the construction shown, or you can make a wood / plastic inner coil former and screw / glue it between two sheets to form the ends of the coil. I suggest winding it using a bolt through the centre gripped by a hand drill, held in a vice. Use some fine plastic tube to guide the wire onto the coil. Spray cans usually have suitable tube if you open one up. I use two part Acrylic glue - Devcon Plastic Welder or similar.

       I defiitely avoid using 'coil dope' - I find that I get too many shorted turns. You can use coil dope OK if you very carefully wind a single layer of wire at a time and then use tissue paper to interleave the winding layers.

       With luck, you are only going to ever make one coil per seismometer, so it REALL IS worth a bit of extra effort to get the best out of your instrument.

       Regards,

       Chris Chapman

Subject: RE: Round external coils and stacked internal magnets From: "Gary Lindgren" gel@................. Date: Fri, 16 May 2008 22:07:41 -0700 Meredith, I can't visualize the magnet layout you speak of with 3 magnets. Do you have a magnet placement diagram so that I could map out the magnetic fields. Gary Lindgren From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Friday, May 16, 2008 9:22 PM To: psn-l@.............. Subject: Re: Round external coils and stacked internal magnets Hi Chris and all, Thanks Chris for the extensive reply below. Actually my impression with the stacked magnets came from trying to utilize a old surplus Texas Instruments rectangular coil form, and at the time, the stacked magnets approach seemed quite impressive at the time via a table top and voltmeter experiment. The problem with the coil is it has relatively thin walls, and I'am not so sure that a quad (4) magnet setup is the best or only approach. Its possible to use 3 magnets and essentially get a similar "quad" (4 pole) arrangement, where the fields go through the sides of the coil walls. The coil form shape is quite similar to transformer coil forms, and in a sense there maybe 2 ways to use magnets with them. Esterline-Angus also made similar coils back in the 1950's, of which I also have some of those. I put up a quick web page with 2 photos on the TI coil; along with my "notes/ramblings" related to such: http://seismometer.googlepages.com/tirectiwritercoilconversion Take care, Meredith Lamb On Fri, May 16, 2008 at 2:56 PM, wrote: In a message dated 2008/05/16, paleoartifact@......... writes: Am getting to the (shall we say a unqualified) opinion that with a choice of round or square / rectangular coils with a magnet, that it seems like the round coil approach is the more efficient route to take. Hi Meredith, If you want an accurately linear output from a Lehman, while allowing for the large sensor drifts that you always get, you definitely need to use a quad arrangement of square NdFeB magnets and a rectangular coil. Round coils will DEFINITELY NOT give you a constant sensitivity over the drift range of a Lehman sensor. If you are using a vertical pendulum, you can use a quad arrangement of rectangular magnets with the width of a magnet ~ the ID of the coil. Alternatively, you can make up a magnet block and attach it to the pendulum to form part or all of the mass. But you will then still get a small sensitivity to environmental magnetic fields. You make the ID of the actual windings about 3/4 of the width of a magnet and the internal length about 1/5 greater. This allows for some position error either as the coil swings in an arc or for any setup position error. The flux change for a given magnet movement is then CONSTANT over maybe 3/4" drift with 1" square magnets. Mount the magnets on 1/4" thick mild steel backing plates held apart with zinc plated mild steel bolts. You need to give the mild steel some etch primer and a coat of anti rust paint. I use Hermetite. You paint the whole surface of the plates, then leave them a couple of days for the paint to harden. I make up a cardboard cut-out, clamp it to the plate and slide the magnets into position over the cardboard. This is 'the easy way to do it'! One advantage of this construction is that you only need maybe 2,500 turns on you coil. The voltage output is maybe 10x what you get with a U Alnico magnet. This arrangement is shown on the drawings at http://www.jclahr.com/science/psn/chapman/lehman/index.html It is quite easy to make a rectangular coil former out of thin glass circuit board / sheet glass fibre. DigiKey sell both. You can either use the construction shown, or you can make a wood / plastic inner coil former and screw / glue it between two sheets to form the ends of the coil. I suggest winding it using a bolt through the centre gripped by a hand drill, held in a vice. Use some fine plastic tube to guide the wire onto the coil. Spray cans usually have suitable tube if you open one up. I use two part Acrylic glue - Devcon Plastic Welder or similar. I defiitely avoid using 'coil dope' - I find that I get too many shorted turns. You can use coil dope OK if you very carefully wind a single layer of wire at a time and then use tissue paper to interleave the winding layers. With luck, you are only going to ever make one coil per seismometer, so it REALL IS worth a bit of extra effort to get the best out of your instrument. Regards, Chris Chapman

Meredith,

I can’t visualize the magnet layout you speak of = with 3 magnets. Do you have a magnet placement diagram so that I could map out the = magnetic fields.

Gary Lindgren

 

 

 

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Friday, May 16, 2008 9:22 PM
To: psn-l@..............
Subject: Re: Round external coils and stacked internal = magnets

 

Hi Chris and = all,

Thanks Chris for the extensive reply below.  Actually my impression = with the stacked magnets came from
trying to utilize a old surplus Texas Instruments rectangular coil form, = and at the time, the stacked
magnets approach seemed quite impressive at the time via a table top and voltmeter experiment.

The problem with the coil is it has relatively thin walls, and I'am not = so sure that a quad (4) magnet
setup is the best or only approach.  Its possible to use 3 magnets = and essentially get a similar "quad" (4 pole)
arrangement, where the fields go through the sides of the coil = walls.

The coil form shape is quite similar to transformer coil forms, and in a = sense there maybe 2 ways to
use magnets with them.  Esterline-Angus also made similar coils = back in the 1950's, of which
I also have some of those.

I put up a quick web page with 2 photos on the TI coil; along with my "notes/ramblings" related to such:

h= ttp://seismometer.googlepages.com/tirectiwritercoilconversion

Take care, Meredith Lamb

On Fri, May 16, 2008 at 2:56 PM, <ChrisAtUpw@.......> = wrote:

In a message dated 2008/05/16, paleoartifact@......... writes:


Am getting to the (shall we say a unqualified) opinion that with a choice = of round or square / rectangular coils with a magnet, that it seems like the = round coil approach is the more efficient route to take.

 

Hi Meredith,

       If you want an accurately linear = output from a Lehman, while allowing for the large sensor drifts that you = always get, you definitely need to use a quad arrangement of square NdFeB magnets = and a rectangular coil.

       Round coils will DEFINITELY NOT = give you a constant sensitivity over the drift range of a Lehman sensor.
       If you are using a vertical = pendulum, you can use a quad arrangement of rectangular magnets with the width of a = magnet ~ the ID of the coil. Alternatively, you can make up a magnet block and = attach it to the pendulum to form part or all of the mass. But you will then still = get a small sensitivity to environmental magnetic fields.

       You make the ID of the actual = windings about 3/4 of the width of a magnet and the internal length about 1/5 = greater. This allows for some position error either as the coil swings in an arc = or for any setup position error.  The flux change for a given magnet = movement is then CONSTANT over maybe 3/4" drift with 1" square = magnets.

       Mount the magnets on 1/4" = thick mild steel backing plates held apart with zinc plated mild steel bolts. You = need to give the mild steel some etch primer and a coat of anti rust paint. I = use Hermetite. You paint the whole surface of the plates, then leave them a = couple of days for the paint to harden. I make up a cardboard cut-out, clamp it = to the plate and slide the magnets into position over the cardboard. This is = 'the easy way to do it'!

       One advantage of this construction = is that you only need maybe 2,500 turns on you coil. The voltage output is maybe = 10x what you get with a U Alnico magnet.

       This arrangement is shown on the = drawings at http://www.jclahr.com/science/psn/chapman/lehman/index.= html

       It is quite easy to make a = rectangular coil former out of thin glass circuit board / sheet glass fibre. DigiKey = sell both. You can either use the construction shown, or you can make a wood = / plastic inner coil former and screw / glue it between two sheets to form = the ends of the coil. I suggest winding it using a bolt through the centre = gripped by a hand drill, held in a vice. Use some fine plastic tube to guide the = wire onto the coil. Spray cans usually have suitable tube if you open one up. = I use two part Acrylic glue - Devcon Plastic Welder or similar.

       I defiitely avoid using 'coil dope' = - I find that I get too many shorted turns. You can use coil dope OK if you = very carefully wind a single layer of wire at a time and then use tissue = paper to interleave the winding layers.

       With luck, you are only going to = ever make one coil per seismometer, so it REALL IS worth a bit of extra effort to = get the best out of your instrument.

       Regards,

       Chris Chapman

 

Subject: Re: Round external coils and stacked internal magnets From: "meredith lamb" paleoartifact@......... Date: Sat, 17 May 2008 00:52:04 -0600 Hi Gary, Imagine (or use) a rectangular piece of paper as the flat "steel plate". On it, place/lay 3 pencils spaced apart @ say 2 inches. The pencils are the imaginary rectangular "magnets" stuck to the " steel plate". The magnets are polarized through their thickness; and hence are arranged with say, the left magnet with the N pole up, then the center "magnet" has the S pole up, and the right pencil has the N pole up. The imaginary coil goes over the the center "magnet" (up-down motion) and in between the outer "magnets". This type of magnet is often called a motor or wind generator magnet, as the poles are through the thickness and not at the ends. Every magnet has two poles. Hence their is two attracting fields in between the left "magnet" and the center "magnet". The same goes with the same center "magnet" and the right "magnet"; hence you have 4 attracting fields acting on the single coil. The fields are of course, relatively straight across to the adjacent attracting magnet. The intensity of the fields depends on the magnets ratings, how close they are together, and it also depends on the coil itself. For example; If you only have one magnet you "could" get for example, say 3v max velocity. With two, it could jump to ~ 8v; but with 3 it probably goes over 15v max velocity. Of course it all depends on the coil used and the magnet rating and the magnet spacing. Take care, Meredith On Fri, May 16, 2008 at 11:07 PM, Gary Lindgren wrote: > Meredith, > > I can't visualize the magnet layout you speak of with 3 magnets. Do you > have a magnet placement diagram so that I could map out the magnetic fields. > > Gary Lindgren > > > > > > > > > > *From:* psn-l-request@.............. [mailto:psn-l-request@............... > *On Behalf Of *meredith lamb > *Sent:* Friday, May 16, 2008 9:22 PM > *To:* psn-l@.............. > *Subject:* Re: Round external coils and stacked internal magnets > > > > Hi Chris and all, > > Thanks Chris for the extensive reply below. Actually my impression with > the stacked magnets came from > trying to utilize a old surplus Texas Instruments rectangular coil form, > and at the time, the stacked > magnets approach seemed quite impressive at the time via a table top and > voltmeter experiment. > > The problem with the coil is it has relatively thin walls, and I'am not so > sure that a quad (4) magnet > setup is the best or only approach. Its possible to use 3 magnets and > essentially get a similar "quad" (4 pole) > arrangement, where the fields go through the sides of the coil walls. > > The coil form shape is quite similar to transformer coil forms, and in a > sense there maybe 2 ways to > use magnets with them. Esterline-Angus also made similar coils back in the > 1950's, of which > I also have some of those. > > I put up a quick web page with 2 photos on the TI coil; along with my > "notes/ramblings" related to such: > > http://seismometer.googlepages.com/tirectiwritercoilconversion > > Take care, Meredith Lamb > > On Fri, May 16, 2008 at 2:56 PM, wrote: > > In a message dated 2008/05/16, paleoartifact@......... writes: > > > Am getting to the (shall we say a unqualified) opinion that with a choice > of round or square / rectangular coils with a magnet, that it seems like the > round coil approach is the more efficient route to take. > > > > Hi Meredith, > > If you want an accurately linear output from a Lehman, while > allowing for the large sensor drifts that you always get, you definitely > need to use a quad arrangement of square NdFeB magnets and a rectangular > coil. > > Round coils will DEFINITELY NOT give you a constant sensitivity over > the drift range of a Lehman sensor. > If you are using a vertical pendulum, you can use a quad arrangement > of rectangular magnets with the width of a magnet ~ the ID of the coil. > Alternatively, you can make up a magnet block and attach it to the pendulum > to form part or all of the mass. But you will then still get a small > sensitivity to environmental magnetic fields. > > You make the ID of the actual windings about 3/4 of the width of a > magnet and the internal length about 1/5 greater. This allows for some > position error either as the coil swings in an arc or for any setup position > error. The flux change for a given magnet movement is then CONSTANT over > maybe 3/4" drift with 1" square magnets. > > Mount the magnets on 1/4" thick mild steel backing plates held apart > with zinc plated mild steel bolts. You need to give the mild steel some etch > primer and a coat of anti rust paint. I use Hermetite. You paint the whole > surface of the plates, then leave them a couple of days for the paint to > harden. I make up a cardboard cut-out, clamp it to the plate and slide the > magnets into position over the cardboard. This is 'the easy way to do it'! > > One advantage of this construction is that you only need maybe 2,500 > turns on you coil. The voltage output is maybe 10x what you get with a U > Alnico magnet. > > This arrangement is shown on the drawings at > http://www.jclahr.com/science/psn/chapman/lehman/index.html > > It is quite easy to make a rectangular coil former out of thin glass > circuit board / sheet glass fibre. DigiKey sell both. You can either use the > construction shown, or you can make a wood / plastic inner coil former and > screw / glue it between two sheets to form the ends of the coil. I suggest > winding it using a bolt through the centre gripped by a hand drill, held in > a vice. Use some fine plastic tube to guide the wire onto the coil. Spray > cans usually have suitable tube if you open one up. I use two part Acrylic > glue - Devcon Plastic Welder or similar. > > I defiitely avoid using 'coil dope' - I find that I get too many > shorted turns. You can use coil dope OK if you very carefully wind a single > layer of wire at a time and then use tissue paper to interleave the winding > layers. > > With luck, you are only going to ever make one coil per seismometer, > so it REALL IS worth a bit of extra effort to get the best out of your > instrument. > > Regards, > > Chris Chapman > > > Hi Gary,

Imagine (or use) a rectangular piece of paper as the flat "steel plate".  On it, place/lay 3 pencils spaced apart
@ say 2 inches.  The pencils are the imaginary rectangular "magnets" stuck to the " steel plate".  The magnets are polarized through their thickness; and hence are arranged with say, the left magnet with the N pole up, then
the center "magnet" has the S pole up, and the right pencil has the N pole up.  The imaginary coil goes
over the the center "magnet" (up-down motion) and in between the outer "magnets".  This type of magnet is
often called a motor or wind generator magnet, as the poles are through the thickness and not at the ends.

Every magnet has two poles.  Hence their is two attracting fields in between the left "magnet" and the
center "magnet".  The same goes with the same center "magnet" and the right "magnet"; hence you have
4 attracting fields acting on the single coil.  The fields are of course, relatively straight across to the adjacent
attracting magnet.

The intensity of the fields depends on the magnets ratings, how close they are together, and it also
depends on the coil itself. 

For example; If you only have one magnet you "could" get for example, say 3v max velocity.  With two, it
could jump to ~ 8v;  but with 3 it probably goes over 15v max velocity.  Of course it all depends on the coil
used and the magnet rating and the magnet spacing.

Take care, Meredith

On Fri, May 16, 2008 at 11:07 PM, Gary Lindgren <gel@.................> wrote:

Meredith,

I can't visualize the magnet layout you speak of with 3 magnets. Do you have a magnet placement diagram so that I could map out the magnetic fields.

Gary Lindgren

 

 

 

 

From: psn-l-request@.............. [mailto:psn-l-request@..............] On Behalf Of meredith lamb
Sent: Friday, May 16, 2008 9:22 PM
To: psn-l@..............
Subject: Re: Round external coils and stacked internal magnets

 

Hi Chris and all,

Thanks Chris for the extensive reply below.  Actually my impression with the stacked magnets came from
trying to utilize a old surplus Texas Instruments rectangular coil form, and at the time, the stacked
magnets approach seemed quite impressive at the time via a table top and voltmeter experiment.

The problem with the coil is it has relatively thin walls, and I'am not so sure that a quad (4) magnet
setup is the best or only approach.  Its possible to use 3 magnets and essentially get a similar "quad" (4 pole)
arrangement, where the fields go through the sides of the coil walls.

The coil form shape is quite similar to transformer coil forms, and in a sense there maybe 2 ways to
use magnets with them.  Esterline-Angus also made similar coils back in the 1950's, of which
I also have some of those.

I put up a quick web page with 2 photos on the TI coil; along with my "notes/ramblings" related to such:

http://seismometer.googlepages.com/tirectiwritercoilconversion

Take care, Meredith Lamb

On Fri, May 16, 2008 at 2:56 PM, <ChrisAtUpw@.......> wrote:

In a message dated 2008/05/16, paleoartifact@......... writes:


Am getting to the (shall we say a unqualified) opinion that with a choice of round or square / rectangular coils with a magnet, that it seems like the round coil approach is the more efficient route to take.

 

Hi Meredith,

       If you want an accurately linear output from a Lehman, while allowing for the large sensor drifts that you always get, you definitely need to use a quad arrangement of square NdFeB magnets and a rectangular coil.

       Round coils will DEFINITELY NOT give you a constant sensitivity over the drift range of a Lehman sensor.
       If you are using a vertical pendulum, you can use a quad arrangement of rectangular magnets with the width of a magnet ~ the ID of the coil. Alternatively, you can make up a magnet block and attach it to the pendulum to form part or all of the mass. But you will then still get a small sensitivity to environmental magnetic fields.

       You make the ID of the actual windings about 3/4 of the width of a magnet and the internal length about 1/5 greater. This allows for some position error either as the coil swings in an arc or for any setup position error.  The flux change for a given magnet movement is then CONSTANT over maybe 3/4" drift with 1" square magnets.

       Mount the magnets on 1/4" thick mild steel backing plates held apart with zinc plated mild steel bolts. You need to give the mild steel some etch primer and a coat of anti rust paint. I use Hermetite. You paint the whole surface of the plates, then leave them a couple of days for the paint to harden. I make up a cardboard cut-out, clamp it to the plate and slide the magnets into position over the cardboard. This is 'the easy way to do it'!

       One advantage of this construction is that you only need maybe 2,500 turns on you coil. The voltage output is maybe 10x what you get with a U Alnico magnet.

       This arrangement is shown on the drawings at http://www.jclahr.com/science/psn/chapman/lehman/index.html

       It is quite easy to make a rectangular coil former out of thin glass circuit board / sheet glass fibre. DigiKey sell both. You can either use the construction shown, or you can make a wood / plastic inner coil former and screw / glue it between two sheets to form the ends of the coil. I suggest winding it using a bolt through the centre gripped by a hand drill, held in a vice. Use some fine plastic tube to guide the wire onto the coil. Spray cans usually have suitable tube if you open one up. I use two part Acrylic glue - Devcon Plastic Welder or similar.

       I defiitely avoid using 'coil dope' - I find that I get too many shorted turns. You can use coil dope OK if you very carefully wind a single layer of wire at a time and then use tissue paper to interleave the winding layers.

       With luck, you are only going to ever make one coil per seismometer, so it REALL IS worth a bit of extra effort to get the best out of your instrument.

       Regards,

       Chris Chapman

 


Subject: Re: Oil Furnace Nozzle Connection From: "Connie & Jim Lehman" lehmancj@........... Date: Sat, 17 May 2008 06:58:09 -0400 Gary--the use of an oil furnace nozzle was adopted in the original = design as it it made a clean "hinge" for the wire support. We got the = idea from a support for a 6 ft. Foucault Pendulum demo that worked well. = The nozzle used had a half inch screw area. We drilled a half inch = hole is the upper crosspiece at an angle the wire support wire would = be--making a snug fit, Then epoxy the nozzle in place. Whatever wire = is chosen must support the mass without fatigue, and must pass through = the nozzle---enlarge the opening as necessary--but make it snug. Drill = a small hole on the back side of the upper crosspiece, bring the wire = out and anchor. If everything is pretty well in line, there is little = stress on the nozzle--and it can do its thing! There are other designs for the hinges-upper & lower-- that work = well--Whatever you choose you want stability with a good structural = support and minimal fatigue over time. Best wishes, Jim Lehman ----- Original Message -----=20 From: Gary Lindgren=20 To: PSN List=20 Sent: Friday, May 16, 2008 6:13 PM Subject: Oil Furnace Nozzle Connection The typical Lehman uses an oil furnace nozzle as a connection point = for the upper end of the music wire that is attached to the boom. What = method is used to modify the nozzle in order to fasten the wire. What = modifications are made. Thank you Gary Lindgren =20 =20 =20 =20 Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 =20 650-326-0655 =20 www.blue-eagle-technologies.com cymonsplace.blogspot.com=20 =20
Gary--the use of an oil furnace nozzle = was adopted=20 in the original design as it it made a clean "hinge" for the wire = support. =20 We got the idea from a support for a 6 ft. Foucault Pendulum demo = that=20 worked well.  The nozzle used had a half inch screw area.  We = drilled=20 a half inch hole is the upper crosspiece at an angle the wire support = wire would=20 be--making a snug fit,  Then epoxy the nozzle in place.  = Whatever wire=20 is chosen must support the mass without fatigue, and must pass through = the=20 nozzle---enlarge the opening as necessary--but make it snug.  Drill = a=20 small hole on the back side of the upper crosspiece, bring the wire = out and=20 anchor.  If everything is pretty well in line, there is little = stress on=20 the nozzle--and it can do its thing!
  There are other designs for the = hinges-upper=20 & lower-- that work well--Whatever you choose   you = want=20 stability with a good structural support and minimal fatigue = over=20 time.
 
Best wishes,  Jim = Lehman
----- Original Message -----
From:=20 Gary=20 Lindgren
Sent: Friday, May 16, 2008 6:13 = PM
Subject: Oil Furnace Nozzle=20 Connection

The typical Lehman uses an oil furnace nozzle as = a=20 connection point for the upper end of the music wire that is attached = to the=20 boom. What method is used to modify the nozzle in order to fasten the = wire.=20 What modifications are made.

Thank you

Gary Lindgren

 

 

 

 

Gary=20 Lindgren

585 = Lincoln=20 Ave

Palo Alto = CA=20 94301

 

650-326-0655

 

www.blue-eagle-technologies.com

cymonsplace.blogspot.com 

 

Subject: Re: China Quake<< wrote: Hi all Here are two articals on the China earthquake. http://news.nationalgeographic.com/news/2008/05/080516-earthquake-predic= ted.html http://news.nationalgeographic.com/news/2008/05/080515-AP-china-quake.ht= ml Regards. -- = J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) See http://www.seismicnet.com/maillist.html for more information. _____________________________________________________________ Don't stay in a roach motel. Click here to find great deals on hotels. http://thirdpartyoffers.juno.com/TGL2121/fc/Ioyw6i3nLmKrCkIgePSCUZTrK1v8= qDsxTLMdB1fZCtCFsLDwBFDN2y/?count=3D1234567890 Thanks Jon- The 2 articles are Outstanding.....Jim 

--= J=F3n Fr=EDmann <jonfr@.........> wrote:
Hi all

Here ar= e two articals on the China earthquake.

http://news.nationalgeogr= aphic.com/news/2008/05/080516-earthquake-predicted.html
http://news.n= ationalgeographic.com/news/2008/05/080515-AP-china-quake.html

Reg= ards.
--
J=F3n Fr=EDmann
http://www.jonfr.com
http://earthq= uakes.jonfr.com
http://www.net303.net
http://www.mobile-coverage.c= om/

__________________________________________________________
Public Seismic Network Mailing List (PSN-L)

To leave this li= st email PSN-L-REQUEST@.............. with
the body of the message (= first line only): unsubscribe
See http://www.seismicnet.com/maillist.= html for more information.

__________________________= ___________________________________
Don't stay in a roach motel. = Click here to find great deals on hotels.
Subject: Re: China Quake From: "Dale Hardy" photon1@........... Date: Wed, 21 May 2008 23:45:24 +1000 Some dramatic images of the changed landscape after the event,.... watch for word wrap Dale http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=18034 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Expecting a big earthquake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 22 May 2008 19:45:49 +0000 Hi all There is an earthquake swarm happening about 93 km south of my location (see here, http://hraun.vedur.is/ja/englishweb/index.html ). This swarm did start on Monday with few small earthquakes, but this morning it did release a M3.5 earthquake and many other smaller onces. Given the earthquake swarm pattern I am expecting a earthquake there that is ML4.0 up to ML5.5, but I doubt it is going to get bigger then mag 5.5. I expect this earthquake to happen in next two days at least, but this might take longer time to happen. That area last had a earthquake swarm in 1999, then it did start with a ML4.0 earthquake. Also in general earthquake news from Iceland it appears that number of earthquakes are on the rise, there appears to be high tension in the crust in Iceland. Earthquake recording might get intresting at any time for me. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Adjusting the period From: tchannel1@............ Date: Mon, 26 May 2008 08:29:07 -0600 Hi Folks, I have a Lehman set to 20 seconds..........It seems to be = working okay and I don't think it needs any modifications. It records = the same as other Lehmans I have worked with. I plan on changing the period from 20 seconds to another number, not = sure what that number will be. What I want to see, is how it records = at different period settings. I know the advantages of the 20 seconds. The disadvantage is it misses = many other smaller earthquakes. My question: Before I try other period numbers..........Have you tried = this, and what were the results? I really don't know what the result would be. Thanks, Ted
Hi  Folks,  I have a Lehman = set to 20=20 seconds..........It seems to be working okay and I don't think it needs = any=20 modifications.  It records the same as other Lehmans I have worked=20 with.
 
I plan on changing the period from 20 = seconds to=20 another number, not sure what that number will be.   What I = want to=20 see, is how it records at different period settings.
 
I know the advantages of the 20 = seconds.  The=20 disadvantage is it misses many other smaller earthquakes.
 
My question:  Before I try other = period=20 numbers..........Have you tried this, and what were the = results?
 
I really don't know what the result = would=20 be.
 
Thanks, Ted
Subject: Large earthquake triggers small onces at large distance From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Mon, 26 May 2008 18:23:54 +0000 Hi all It appears that large earthquakes, specally those how are bigger then Mw7.0 can trigger smaller earthquakes at great disance. Two articals about this below. http://www.sciencedaily.com/releases/2008/05/080525132352.htm http://www.msnbc.msn.com/id/24820044/ Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Adjusting the period From: ChrisAtUpw@....... Date: Mon, 26 May 2008 14:51:02 EDT In a message dated 2008/05/26, tchannel1@............ writes: > I plan on changing the period from 20 seconds to another number, not sure > what that number will be. What I want to see, is how it records at different > period settings. > I know the advantages of the 20 seconds. The disadvantage is it misses many > other smaller earthquakes. > My question: Before I try other period numbers..........Have you tried > this, and what were the results? > I really don't know what the result would be. Hi Ted, If your Lehman is working properly, it should see all signals between the natural resonant period, at say 20 seconds and the low pass fiolter of your amplifier at 10 Hz. If you set the period to 10 seconds, it will only record signals between 10 seconds and 10 Hz. It will have about 1/4 theprevious sensitivity to 20 second Love waves. You WILL NOT see any more Earthquakes this way. Remember that Lehmans are directional? Could this be why you are missing some quakes? What quakes have you missed and why do you think you should have recorded them? An alternative is that your suspension may be sticking and preventing the arm from moving freely. You may then only see larger quakes. Can you remind me what suspensions, top and bottom, you are using, please? Do you see the normal 4 to 8 second microseisms OK? Regards, Chris Chapman In a me= ssage dated 2008/05/26, tchannel1@............ writes:

I plan on changing the period f= rom 20 seconds to another number, not sure what that number will be. &n= bsp; What I want to see, is how it records at different period settings. I know the advantages of the 20 seconds.  The disadvantage is it misse= s many other smaller earthquakes.
My question:  Before I try other period numbers..........Have you trie= d this, and what were the results?
I really don't know what the result would be.


Hi Ted,

       If your Lehman is working properly, it=20= should see all signals between the natural resonant period, at say 20 second= s and the low pass fiolter of your amplifier at 10 Hz.

       If you set the period to 10 seconds, it= will only record signals between 10 seconds and 10 Hz. It will have about 1= /4 theprevious sensitivity to 20 second Love waves.

       You WILL NOT see any more Earthquakes t= his way.

       Remember that Lehmans are directional?=20= Could this be why you are missing some quakes? What quakes have you missed a= nd why do you think you should have recorded them?
       An alternative is that your suspension=20= may be sticking and preventing the arm from moving freely. You may then only= see larger quakes.
       Can you remind me what suspensions, top= and bottom, you are using, please?
       Do you see the normal 4 to 8 second mic= roseisms OK?

       Regards,

       Chris Chapman
Subject: Re: Adjusting the period From: "Geoff" gmvoeth@........... Date: Mon, 26 May 2008 12:58:23 -0700 The Smaller The Bandwidth the lower the noise. Id recommend you try 4 seconds to your highest non-alising freq. But your electronics needs to match your hardware and I do not know unless you build your own how to deal with that. ----- Original Message ----- From: To: "psn" Sent: Monday, May 26, 2008 7:29 AM Subject: Adjusting the period Hi Folks, I have a Lehman set to 20 seconds..........It seems to be working okay and I don't think it needs any modifications. It records the same as other Lehmans I have worked with. I plan on changing the period from 20 seconds to another number, not sure what that number will be. What I want to see, is how it records at different period settings. I know the advantages of the 20 seconds. The disadvantage is it misses many other smaller earthquakes. My question: Before I try other period numbers..........Have you tried this, and what were the results? I really don't know what the result would be. Thanks, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Adjusting the period From: ChrisAtUpw@....... Date: Mon, 26 May 2008 16:55:07 EDT In a message dated 2008/05/26, gmvoeth@........... writes: > The Smaller The Bandwidth the lower the noise. I'd recommend you try 4 > seconds to your highest non-alising freq. But your electronics needs to match > your > hardware and I do not know unless you build your own how to deal with that. Hi Geoff, Sure, but with Lehmans in Amateur situations you are usually limited by environmental noise, NOT by electronic noise. Regards, Chris Chapman In a me= ssage dated 2008/05/26, gmvoeth@........... writes:

The Smaller The Bandwidth the l= ower the noise. I'd recommend you try 4 seconds to your highest non-alising=20= freq. But your electronics needs to match your
hardware and I do not know unless you build your own how to deal with that.<= /BLOCKQUOTE>

Hi Geoff,

       Sure, but with Lehmans in Amateur situa= tions you are usually limited by environmental noise, NOT by electronic nois= e.

       Regards,

       Chris Chapman
Subject: Re: Adjusting the period From: tchannel1@............ Date: Mon, 26 May 2008 17:39:01 -0600 Hi Chris, I did double check everything, and the sensor seems to be = working just fine. The reason I know it is missing earthquakes is that I am running three = channels, One vertical spring, one tiltmeter, and one = Lehman..........The Lehman misses a lot of events the other two record. Yes I think part of it is directional. Would you think this could account for it..............The Lehman is set = for twenty seconds, but at twenty seconds, I think it is maxed out, that = is to say, I don't think I could get 21 seconds. Even 20 seconds, for this unit, may be too much. I say that because it = drifts, sometimes falling 1/2" per week to the left or to the right. I = adjust it back to center and it stays only for a few days. Might it simply be this unit is not capable of working at 20 seconds. = The sticking you mentioned.........could this be because it is = overextended, perhaps this machine is only capable of a WORKING PERIOD = of 15 seconds???? When I set it to 20, and move the boom, it does go to center, but = because of the drift issue, it may not be capable of HOLDING CENTER. and = perhaps this is stopping its sensitivity to all but the larger = earthquakes???? On the good side the events it does record, 6.2 Alaska and 7.8 China, = look really good. Thanks for your help. Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Monday, May 26, 2008 12:51 PM Subject: Re: Adjusting the period In a message dated 2008/05/26, tchannel1@............ writes: I plan on changing the period from 20 seconds to another number, not = sure what that number will be. What I want to see, is how it records = at different period settings. I know the advantages of the 20 seconds. The disadvantage is it = misses many other smaller earthquakes. My question: Before I try other period numbers..........Have you = tried this, and what were the results? I really don't know what the result would be. Hi Ted, If your Lehman is working properly, it should see all signals = between the natural resonant period, at say 20 seconds and the low pass = fiolter of your amplifier at 10 Hz. If you set the period to 10 seconds, it will only record = signals between 10 seconds and 10 Hz. It will have about 1/4 theprevious = sensitivity to 20 second Love waves.=20 You WILL NOT see any more Earthquakes this way. Remember that Lehmans are directional? Could this be why you = are missing some quakes? What quakes have you missed and why do you = think you should have recorded them? An alternative is that your suspension may be sticking and = preventing the arm from moving freely. You may then only see larger = quakes. Can you remind me what suspensions, top and bottom, you are = using, please? Do you see the normal 4 to 8 second microseisms OK? Regards, Chris Chapman
Hi Chris,  I did double check = everything, and=20 the sensor seems to be working just fine.
 
The reason I know it is missing = earthquakes is that=20 I am running three channels, One vertical spring, one tiltmeter, and one = Lehman..........The Lehman misses a lot of events the other two=20 record.
 
Yes I think part of it is = directional.
 
Would you think this could account for=20 it..............The Lehman is set for twenty seconds, but at twenty = seconds, I=20 think it is maxed out, that is to say,  I don't think I could get = 21=20 seconds.
Even 20 seconds, for this unit, may be = too=20 much.   I say that because it drifts, sometimes falling 1/2" = per week=20 to the left or to the right.  I adjust it back to  center and = it stays=20 only for a few days.
 
Might it simply be this unit is not = capable of=20 working at 20 seconds.   The sticking you = mentioned.........could this=20 be because it is overextended, perhaps this machine is only capable of a = WORKING=20 PERIOD of 15 seconds????
 
When I set it to 20, and move the boom, = it does go=20 to center, but because of the drift issue, it may not be capable of = HOLDING=20 CENTER. and perhaps this is stopping its sensitivity to all but the = larger=20 earthquakes????
 
On the good side the events it does = record, 6.2=20 Alaska and 7.8 China, look really good.    Thanks for = your=20 help.
Ted
----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Monday, May 26, 2008 = 12:51 PM
Subject: Re: Adjusting the = period

In a=20 message dated 2008/05/26, tchannel1@............=20 writes:

I plan on changing the period from 20 seconds to another = number,=20 not sure what that number will be.   What I want to see, = is how it=20 records at different period settings.

I know the = advantages of the=20 20 seconds.  The disadvantage is it misses many other smaller=20 earthquakes.
My question:  Before I try other period=20 numbers..........Have you tried this, and what were the = results?
I really don't = know what the=20 result would be.


Hi=20 Ted,

       If your Lehman is = working=20 properly, it should see all signals between the natural resonant = period, at=20 say 20 seconds and the low pass fiolter of your amplifier at 10=20 Hz.

       If you set the period = to 10=20 seconds, it will only record signals between 10 seconds and 10 Hz. It = will=20 have about 1/4 theprevious sensitivity to 20 second Love waves.=20

       You WILL NOT see any more = Earthquakes this way.

       = Remember=20 that Lehmans are directional? Could this be why you are missing some = quakes?=20 What quakes have you missed and why do you think you should have = recorded=20 them?
       An alternative is that = your=20 suspension may be sticking and preventing the arm from moving freely. = You may=20 then only see larger quakes.
       = Can you=20 remind me what suspensions, top and bottom, you are using,=20 please?
       Do you see the normal = 4 to 8=20 second microseisms OK?

      =20 Regards,

       Chris = Chapman
=20
Subject: Re: Adjusting the period From: ChrisAtUpw@....... Date: Mon, 26 May 2008 22:05:40 EDT In a message dated 2008/05/27, tchannel1@............ writes: > The reason I know it is missing earthquakes is that I am running three > channels, One vertical spring, one tiltmeter, and one Lehman..........The Lehman > misses a lot of events the other two record. Hi Ted, OK. I accept that. Which compass direction is the boom please? > Yes I think part of it is directional. > > Would you think this could account for it..............The Lehman is set for > twenty seconds, but at twenty seconds, I think it is maxed out, that is to > say, I don't think I could get 21 seconds. > Even 20 seconds, for this unit, may be too much. I say that because it > drifts, sometimes falling 1/2" per week to the left or to the right. I adjust > it back to center and it stays only for a few days. > > Might it simply be this unit is not capable of working at 20 seconds. The > sticking you mentioned.........could this be because it is overextended, > perhaps this machine is only capable of a WORKING PERIOD of 15 seconds? No. If it works at 20 seconds, it should continue to do so. I am talking about stiction in the bearings. When we first tried out our school seismometer, they had not fitted a hard counterplate on the end of the Aluminum boom as I had specified, just a SS bearing on the vertical. The bearing made a tiny dent on the end of the boom and it did not respond properly. I then glued a SS scalpel blade to the boom and it was like a different instrument! What happens if you try to increase the period beyond 20 seconds? The original type Lehmans with a knife edge for the bottom bearing had difficulty getting beyond about 12 seconds. The knife edge either failed or dug into the counterface. A really dumb idea. > When I set it to 20, and move the boom, it does go to center, but because > of the drift issue, it may not be capable of HOLDING CENTER. and perhaps this > is stopping its sensitivity to all but the larger earthquakes? The instability could have several causes. One of these is the suspensions. You have not reminded me what you are using for the top and bottom suspensions! The drift with time could be related to temperature changes, maybe direct movement of the adjustment screws or movement over the ground due to differential expansion of the frame. What metal are the adjustement screws? Is the threaded insert / nut made from the same metal? Do you have three SS metal plates glued to the floor to support the adustment screws? Or are the screws in direct contact with the floor? I fit a nut and a WAVY spring washer on TOP of the baseplate, so that the three adjustment screws are ALWAYS held in tension. I am not 'being fussy'. The axis offset is maybe 0.32 degree - 0.1" if the vertical is 18" high. It is much more likely to be direct tilt of the floor. Where is the seismometer located? What sort of floor is it? Is the seismometer right next to an outside wall? Which direction does the wall face? What are the dimensions of the Lehman, what is the boom made of and what is the mass? Regards, Chris Chapman In a me= ssage dated 2008/05/27, tchannel1@............ writes:

The reason I know it is missing= earthquakes is that I am running three channels, One vertical spring, one t= iltmeter, and one Lehman..........The Lehman misses a lot of events the othe= r two record.


Hi Ted,

       OK. I accept that. Which compass direct= ion is the boom please?


Yes I think part of it is dire= ctional.

Would you think this could account for it..............The Lehman is set fo= r twenty seconds, but at twenty seconds, I think it is maxed out, that is to= say,  I don't think I could get 21 seconds.
Even 20 seconds, for this unit, may be too much.   I say that bec= ause it drifts, sometimes falling 1/2" per week to the left or to the right.=   I adjust it back to  center and it stays only for a few days.
Might it simply be this unit is not capable of working at 20 seconds. The s= ticking you mentioned.........could this be because it is overextended, perh= aps this machine is only capable of a WORKING PERIOD of 15 seconds?

       No. If it works at 20 seconds, it shou= ld continue to do so. I am talking about stiction in the bearings. When we f= irst tried out our school seismometer, they had not fitted a hard counterpla= te on the end of the Aluminum boom as I had specified, just a SS bearing on=20= the vertical. The bearing made a tiny dent on the end of the boom and it did= not respond properly. I then glued a SS scalpel blade to the boom and it wa= s like a different instrument!

       What happens if you try to increase the= period beyond 20 seconds? The original type Lehmans with a knife edge for t= he bottom bearing had difficulty getting beyond about 12 seconds. The knife=20= edge either failed or dug into the counterface. A really dumb idea.


When I set it to 20, and move= the boom, it does go to center, but because of the drift issue, it may not=20= be capable of HOLDING CENTER. and perhaps this is stopping its sensitivity t= o all but the larger earthquakes?


       The instability could have several caus= es. One of these is the suspensions. You have not reminded me what you are u= sing for the top and bottom suspensions!

       The drift with time could be related to= temperature changes, maybe direct movement of the adjustment screws or move= ment over the ground due to differential expansion of the frame. What metal=20= are the adjustement screws? Is the threaded insert / nut made from the same=20= metal? Do you have three SS metal plates glued to the floor to support the a= dustment screws? Or are the screws in direct contact with the floor? I fit a= nut and a WAVY spring washer on TOP of the baseplate, so that the three adj= ustment screws are ALWAYS held in tension.

       I am not 'being fussy'.  The axis=20= offset is maybe 0.32 degree - 0.1" if the vertical is 18" high.

       It is much more likely to be direct til= t of the floor. Where is the seismometer located? What sort of floor is it?=20= Is the seismometer right next to an outside wall? Which direction does the w= all face?

       What are the dimensions of the Lehman,=20= what is the boom made of and what is the mass?

       Regards,

       Chris Chapman
Subject: 1018 steel for neo magnet damp & pickup coil web price variation From: "meredith lamb" paleoartifact@......... Date: Tue, 27 May 2008 11:07:33 -0600 Hi all, If you're interested in trying out the steel plates used with neodymium metals of recent PSN email notes and are looking for a steel source; here is a potential web source. I note that speedy metals.com sells 1018 grade steel at about 1/2 the price of onlinemetals.com. For example; the 1/4" thick X 2" x 3" plate that Chris Chapman sized for his coil, sells for $4.68 for FOUR pieces; versus $9.12 via On line metals.com; for the same quanity and size. Larger sizes will have corresponding higher prices. (The 4 pieces mentioned could potentially work for both a coil pickup and mass dampening needs.) Speedy metals can cut by the inch; while on line metals calls (the same) a "custom cut". Neither have a minimum order. Speedy metals does limit the maximum "inch" overall length to 105". Both companies usually have potentially a - zero to 1/8" oversize cut. I've not ordered anything from Speedy metals, so I can't say plus or minus; however, they sell on E-Bay and have a good reputation. For on line metals, I've had experience. They may take ~ 3 weeks to deliver. Which might prove to be true also with Speedy metals for the special/custom cut/sheared sizes. The "Kicker" for both is that they both prefer to ship via UPS....figure on a extra added high ~ $8.00 > charge or more (!). To be fair, USPS isn't likely any cheaper. Of course, one will still have to drill the holes in the plates and likely file/deburr such and etc. ***Unless you're replicating the size above, it would do well, to seriously consider a larger size of steel plates too "fit all" present or future coils/dampening expectations. The larger size would give more room for a variety of neo magnets, coils, dampening plate widths. http://www.speedymetals.com http://www.onlinemetals.com In Denver, I've checked four major hardware outlets, and none had any mild steel of the base thickness and width size/s above. There was limited 1/8" thick mild/bright/unknown steel and plenty of the lesser useful black high carbon stuff. None had any useful steel "L" brackets that would work either. High carbon angle iron "might" work, but its usually not very squared; and would require alot of file/grinding work. Scrap yards "might" yield something; but then you have to have the machinery for cutting and etc. Some scrap yards can cut too size for a extra charge. In the end; its likely the only means for the average limited tool person is to order via the web, and still have a punch, drill and file.... The cost seems to be all supply and demand (mainly the growing giants China-India), and transportation oil price related. Take care, Meredith Lamb Hi all,

If you're interested in trying out the steel plates used with neodymium metals of recent PSN email
notes and are looking for a steel source; here is a potential web source.

I note that speedy metals.com sells 1018 grade steel at about 1/2 the price of onlinemetals.com.

For example; the 1/4" thick X 2" x 3" plate that Chris Chapman sized for his coil, sells for $4.68 for FOUR
pieces; versus $9.12 via On line metals.com; for the same quanity and size.  Larger sizes will have
corresponding higher prices.  (The 4 pieces mentioned could potentially work for both a coil pickup and
mass dampening needs.)

Speedy metals can cut by the inch; while on line metals calls (the same) a "custom cut".  Neither have
a minimum order.  Speedy metals does limit the maximum "inch" overall length to 105".

Both companies usually have potentially a - zero to 1/8" oversize cut.

I've not ordered anything from Speedy metals, so I can't say plus or minus; however, they sell on E-Bay
and have a good reputation.

For on line metals, I've had experience.  They may take ~ 3 weeks to deliver.  Which might prove to be
true also with Speedy metals for the special/custom cut/sheared sizes.

The "Kicker" for both is that they both prefer to ship via UPS....figure on a extra added high ~ $8.00 > charge
or more (!).  To be fair, USPS isn't likely any cheaper.

Of course, one will still have to drill the holes in the plates and likely file/deburr such and etc.

***Unless you're replicating the size above, it would do well, to seriously consider a larger size of steel plates too "fit all"
present or future coils/dampening expectations.   The larger size would give more room for a variety of neo
magnets, coils, dampening plate widths. 

http://www.speedymetals.com

http://www.onlinemetals.com

In Denver, I've checked four major hardware outlets, and none had any mild steel of the base thickness and
width size/s above.  There was limited 1/8" thick mild/bright/unknown steel and plenty of the lesser useful black high carbon stuff.
None had any useful steel "L" brackets that would work either.  High carbon angle iron "might" work, but its usually
not very squared; and would require alot of file/grinding work.  Scrap yards "might" yield something; but then you have
to have the machinery for cutting and etc.  Some scrap yards can cut too size for a extra charge.  In the end; its
likely the only means for the average limited tool person is to order via the web, and still have a punch, drill and file....

The cost seems to be all supply and demand (mainly the growing giants China-India), and transportation oil price related.

Take care, Meredith Lamb






Subject: RE: 1018 steel for neo magnet damp & pickup coil web price variation From: "Gary Lindgren" gel@................. Date: Tue, 27 May 2008 10:40:06 -0700 Meredith, You should also check out http://www.metalsupermarkets.com/MSC-storefinder.aspx I ordered the steel plates for the magnets and dimensions were very good. Very good prices too. They also have aluminum. I'm lucky in that I have a store just a few miles away and can pickup a day later. But they have locations around the world. Check it out. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Tuesday, May 27, 2008 10:08 AM To: psn-l@.............. Subject: 1018 steel for neo magnet damp & pickup coil web price variation Hi all, If you're interested in trying out the steel plates used with neodymium metals of recent PSN email notes and are looking for a steel source; here is a potential web source. I note that speedy metals.com sells 1018 grade steel at about 1/2 the price of onlinemetals.com. For example; the 1/4" thick X 2" x 3" plate that Chris Chapman sized for his coil, sells for $4.68 for FOUR pieces; versus $9.12 via On line metals.com; for the same quanity and size. Larger sizes will have corresponding higher prices. (The 4 pieces mentioned could potentially work for both a coil pickup and mass dampening needs.) Speedy metals can cut by the inch; while on line metals calls (the same) a "custom cut". Neither have a minimum order. Speedy metals does limit the maximum "inch" overall length to 105". Both companies usually have potentially a - zero to 1/8" oversize cut. I've not ordered anything from Speedy metals, so I can't say plus or minus; however, they sell on E-Bay and have a good reputation. For on line metals, I've had experience. They may take ~ 3 weeks to deliver. Which might prove to be true also with Speedy metals for the special/custom cut/sheared sizes. The "Kicker" for both is that they both prefer to ship via UPS....figure on a extra added high ~ $8.00 > charge or more (!). To be fair, USPS isn't likely any cheaper. Of course, one will still have to drill the holes in the plates and likely file/deburr such and etc. ***Unless you're replicating the size above, it would do well, to seriously consider a larger size of steel plates too "fit all" present or future coils/dampening expectations. The larger size would give more room for a variety of neo magnets, coils, dampening plate widths. http://www.speedymetals.com http://www.onlinemetals.com In Denver, I've checked four major hardware outlets, and none had any mild steel of the base thickness and width size/s above. There was limited 1/8" thick mild/bright/unknown steel and plenty of the lesser useful black high carbon stuff. None had any useful steel "L" brackets that would work either. High carbon angle iron "might" work, but its usually not very squared; and would require alot of file/grinding work. Scrap yards "might" yield something; but then you have to have the machinery for cutting and etc. Some scrap yards can cut too size for a extra charge. In the end; its likely the only means for the average limited tool person is to order via the web, and still have a punch, drill and file.... The cost seems to be all supply and demand (mainly the growing giants China-India), and transportation oil price related. Take care, Meredith Lamb

Meredith,

You should also check out http://www= ..metalsupermarkets.com/MSC-storefinder.aspx I ordered the steel plates for the magnets and dimensions were very = good. Very good prices too. They also have aluminum. I’m lucky in that I have = a store just a few miles away and can pickup a day later. But they have = locations around the world. Check it out.

Gary 

 

 

 

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Tuesday, May 27, 2008 10:08 AM
To: psn-l@..............
Subject: 1018 steel for neo magnet damp & pickup coil web = price variation

 

Hi all,

If you're interested in trying out the steel plates used with neodymium = metals of recent PSN email
notes and are looking for a steel source; here is a potential web = source.

I note that speedy metals.com sells = 1018 grade steel at about 1/2 the price of onlinemetals.com.

For example; the 1/4" thick X 2" x 3" plate that Chris = Chapman sized for his coil, sells for $4.68 for FOUR
pieces; versus $9.12 via On line metals.com; for the same quanity and size.  Larger sizes will have
corresponding higher prices.  (The 4 pieces mentioned could = potentially work for both a coil pickup and
mass dampening needs.)

Speedy metals can cut by the inch; while on line metals calls (the same) = a "custom cut".  Neither have
a minimum order.  Speedy metals does limit the maximum = "inch" overall length to 105".

Both companies usually have potentially a - zero to 1/8" oversize = cut.

I've not ordered anything from Speedy metals, so I can't say plus or = minus; however, they sell on E-Bay
and have a good reputation.

For on line metals, I've had experience.  They may take ~ 3 weeks = to deliver.  Which might prove to be
true also with Speedy metals for the special/custom cut/sheared = sizes.

The "Kicker" for both is that they both prefer to ship via UPS....figure on a extra added high ~ $8.00 > charge
or more (!).  To be fair, USPS isn't likely any cheaper.

Of course, one will still have to drill the holes in the plates and = likely file/deburr such and etc.

***Unless you're replicating the size above, it would do well, to = seriously consider a larger size of steel plates too "fit all"
present or future coils/dampening expectations.   The larger = size would give more room for a variety of neo
magnets, coils, dampening plate widths. 

http://www.speedymetals.com

http://www.onlinemetals.com

In Denver, I've checked four major hardware outlets, and none had any = mild steel of the base thickness and
width size/s above.  There was limited 1/8" thick = mild/bright/unknown steel and plenty of the lesser useful black high carbon stuff.
None had any useful steel "L" brackets that would work = either.  High carbon angle iron "might" work, but its usually
not very squared; and would require alot of file/grinding work.  = Scrap yards "might" yield something; but then you have
to have the machinery for cutting and etc.  Some scrap yards can = cut too size for a extra charge.  In the end; its
likely the only means for the average limited tool person is to order = via the web, and still have a punch, drill and file....

The cost seems to be all supply and demand (mainly the growing giants China-India), and transportation oil price related.

Take care, Meredith Lamb





Subject: Re: Adjusting the period From: tchannel1@............ Date: Tue, 27 May 2008 13:51:20 -0600 Hi Chris, =20 >Which compass direction is the boom please? East/West > Where is the seismometer located? (Basement) What sort of floor is = it? (Concrete) (ss plates for the legs) >Is the seismometer right next to an outside wall? (Yes)=20 >Which direction does the wall face? (East/West) >What are the dimensions of the Lehman, what is the boom made of and = what is the mass? 36" boom 1/2" alum rod. Dim. 20"wide, 22" tall, 36" = long. The mass is 2.5# Alum cylinder Chris, I think I found the drift issue? I added a wing nut to lock the = legs after adjustment. I think they were moving over time? Thanks, Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Monday, May 26, 2008 8:05 PM Subject: Re: Adjusting the period In a message dated 2008/05/27, tchannel1@............ writes: The reason I know it is missing earthquakes is that I am running = three channels, One vertical spring, one tiltmeter, and one = Lehman..........The Lehman misses a lot of events the other two record. Hi Ted, OK. I accept that. Which compass direction is the boom please? Yes I think part of it is directional. Would you think this could account for it..............The Lehman is = set for twenty seconds, but at twenty seconds, I think it is maxed out, = that is to say, I don't think I could get 21 seconds. Even 20 seconds, for this unit, may be too much. I say that = because it drifts, sometimes falling 1/2" per week to the left or to the = right. I adjust it back to center and it stays only for a few days. Might it simply be this unit is not capable of working at 20 = seconds. The sticking you mentioned.........could this be because it is = overextended, perhaps this machine is only capable of a WORKING PERIOD = of 15 seconds? No. If it works at 20 seconds, it should continue to do so. I = am talking about stiction in the bearings. When we first tried out our = school seismometer, they had not fitted a hard counterplate on the end = of the Aluminum boom as I had specified, just a SS bearing on the = vertical. The bearing made a tiny dent on the end of the boom and it did = not respond properly. I then glued a SS scalpel blade to the boom and it = was like a different instrument! What happens if you try to increase the period beyond 20 = seconds? The original type Lehmans with a knife edge for the bottom = bearing had difficulty getting beyond about 12 seconds. The knife edge = either failed or dug into the counterface. A really dumb idea. When I set it to 20, and move the boom, it does go to center, but = because of the drift issue, it may not be capable of HOLDING CENTER. and = perhaps this is stopping its sensitivity to all but the larger = earthquakes? The instability could have several causes. One of these is the = suspensions. You have not reminded me what you are using for the top and = bottom suspensions! The drift with time could be related to temperature changes, = maybe direct movement of the adjustment screws or movement over the = ground due to differential expansion of the frame. What metal are the = adjustement screws? Is the threaded insert / nut made from the same = metal? Do you have three SS metal plates glued to the floor to support = the adustment screws? Or are the screws in direct contact with the = floor? I fit a nut and a WAVY spring washer on TOP of the baseplate, so = that the three adjustment screws are ALWAYS held in tension.=20 I am not 'being fussy'. The axis offset is maybe 0.32 degree - = 0.1" if the vertical is 18" high. It is much more likely to be direct tilt of the floor. Where is = the seismometer located? What sort of floor is it? Is the seismometer = right next to an outside wall? Which direction does the wall face? What are the dimensions of the Lehman, what is the boom made of = and what is the mass? Regards, Chris Chapman
Hi Chris,    =
 
>Which compass direction is the boom = please?   East/West
 
> Where is the seismometer located?   =20 (Basement)  What sort of floor is it?   (Concrete) =  (ss=20 plates for the legs)
>Is the=20 seismometer right next to an outside wall?   (Yes)=20
>Which=20 direction does the wall face? (East/West)
 
>What=20 are the dimensions of the Lehman, what is the boom made of and what is = the=20 mass?  36" boom 1/2" alum rod.   Dim. 20"wide, 22" tall, = 36"=20 long.  The mass is 2.5# Alum cylinder
 
Chris, I=20 think I found the drift issue?  I added a wing nut to lock the legs = after=20 adjustment.  I think they were moving over = time?
 
Thanks, Ted
 
 




----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Monday, May 26, 2008 8:05 = PM
Subject: Re: Adjusting the = period

In a=20 message dated 2008/05/27, tchannel1@............=20 writes:

The reason I know it is missing earthquakes is that I am = running=20 three channels, One vertical spring, one tiltmeter, and one=20 Lehman..........The Lehman misses a lot of events the other two=20 record.


Hi=20 Ted,

       OK. I accept that. = Which=20 compass direction is the boom please?


Yes I think part of it is directional.

Would you think = this could=20 account for it..............The Lehman is set for twenty seconds, = but at=20 twenty seconds, I think it is maxed out, that is to say,  I = don't think=20 I could get 21 seconds.
Even 20 seconds, for this unit, may be too = much.  =20 I say that because it drifts, sometimes falling 1/2" per week to the = left or=20 to the right.  I adjust it back to  center and it stays = only for a=20 few days.

Might it simply be this unit is not capable of = working at 20=20 seconds. The sticking you mentioned.........could this be because it = is=20 overextended, perhaps this machine is only capable of a WORKING = PERIOD of 15=20 seconds?

       No. If=20 it works at 20 seconds, it should continue to do so. I am talking = about=20 stiction in the bearings. When we first tried out our school = seismometer, they=20 had not fitted a hard counterplate on the end of the Aluminum boom as = I had=20 specified, just a SS bearing on the vertical. The bearing made a tiny = dent on=20 the end of the boom and it did not respond properly. I then glued a SS = scalpel=20 blade to the boom and it was like a different=20 instrument!

       What happens = if you=20 try to increase the period beyond 20 seconds? The original type = Lehmans with a=20 knife edge for the bottom bearing had difficulty getting beyond about = 12=20 seconds. The knife edge either failed or dug into the counterface. A = really=20 dumb idea.


When I=20 set it to 20, and move the boom, it does go to center, but because = of the=20 drift issue, it may not be capable of HOLDING CENTER. and perhaps = this is=20 stopping its sensitivity to all but the larger=20 earthquakes?

       = The=20 instability could have several causes. One of these is the = suspensions. You=20 have not reminded me what you are using for the top and bottom=20 suspensions!

       The drift = with time=20 could be related to temperature changes, maybe direct movement of the=20 adjustment screws or movement over the ground due to differential = expansion of=20 the frame. What metal are the adjustement screws? Is the threaded = insert / nut=20 made from the same metal? Do you have three SS metal plates glued to = the floor=20 to support the adustment screws? Or are the screws in direct contact = with the=20 floor? I fit a nut and a WAVY spring washer on TOP of the baseplate, = so that=20 the three adjustment screws are ALWAYS held in tension.=20

       I am not 'being = fussy'.  The=20 axis offset is maybe 0.32 degree - 0.1" if the vertical is 18"=20 high.

       It is much more = likely to be=20 direct tilt of the floor. Where is the seismometer located? What sort = of floor=20 is it? Is the seismometer right next to an outside wall? Which = direction does=20 the wall face?

       What are = the=20 dimensions of the Lehman, what is the boom made of and what is the=20 mass?

      =20 Regards,

       Chris = Chapman
=20
Subject: Re: Adjusting the period From: ChrisAtUpw@....... Date: Tue, 27 May 2008 16:40:43 EDT In a message dated 2008/05/27, tchannel1@............ writes: > >Is the seismometer right next to an outside wall? (Yes) > >Which direction does the wall face? (East/West) Hi Ted, A location close to a load bearing outside wall is likely to be effected by any movements of the wall, due to rainfall on the soil outside, the effect of the sun raising the wall temperature and also noise from winds. > >What are the dimensions of the Lehman, what is the boom made of and what > is the mass? 36" boom 1/2" alum rod. Dim. 20"wide, 22" tall, 36" long. The > mass is 2.5# Alum cylinder Thanks. What is the weight of the Aluminum cylinder, please - or alternatively it's length? Is it solid Al, 2.5" OD? > Chris, I think I found the drift issue? I added a wing nut to lock the > legs after adjustment. I think they were moving over time? That could well be the problem. Threads are cut at about a 60 degree angle and are rarely a tight fit. If the thread and the nut / threaded insert are not of the same material, you get differential expansion which slides the threads radially. Similarly, unless the adjusting screw is under tension, any differential expansion of the frame relative to the Earth underneath will try to tilt the thread and cause it to slip diagonally. It is preferable to use a wavy spring washer between the wing nut / lock nut and the frame to keep a fairly constant tension. This will not be much effected by the small amounts of differential expansion of the base and the bolt. Let us know if this cures your drift problems? Regards, Chris Chapman In a me= ssage dated 2008/05/27, tchannel1@............ writes:

>Is the seismometer right ne= xt to an outside wall?  (Yes)
>Which direction does the wall face? (East/West)


Hi Ted,

       A location close to a load bearing outs= ide wall is likely to be effected by any movements of the wall, due to rainf= all on the soil outside, the effect of the sun raising the wall temperature=20= and also noise from winds.


>What are the dimensions of= the Lehman, what is the boom made of and what is the mass?  36" boom 1= /2" alum rod.  Dim. 20"wide, 22" tall, 36" long.  The mass is 2.5#= Alum cylinder


       Thanks. What is the weight of the Alum= inum cylinder, please - or alternatively it's length? Is it solid Al, 2.5" O= D?

Chris, I think I found the dri= ft issue?  I added a wing nut to lock the legs after adjustment. =20= I think they were moving over time?


       That could well be the problem. Threads= are cut at about a 60 degree angle and are rarely a tight fit. If the threa= d and the nut / threaded insert are not of the same material, you get differ= ential expansion which slides the threads radially. Similarly, unless the ad= justing screw is under tension, any differential expansion of the frame rela= tive to the Earth underneath will try to tilt the thread and cause it to sli= p diagonally. It is preferable to use a wavy spring washer between the wing=20= nut / lock nut and the frame to keep a fairly constant tension. This will no= t be much effected by the small amounts of differential expansion of the bas= e and the bolt.

       Let us know if this cures your drift pr= oblems?

       Regards,

       Chris Chapman
Subject: Re: Adjusting the period From: tchannel1@............ Date: Tue, 27 May 2008 17:15:57 -0600 Hi Chris, =20 >Is it solid Al, 2.5" OD? I meant to say 2.5 pounds, alum 3" x 3" = cylinder. Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Tuesday, May 27, 2008 2:40 PM Subject: Re: Adjusting the period In a message dated 2008/05/27, tchannel1@............ writes: >Is the seismometer right next to an outside wall? (Yes)=20 >Which direction does the wall face? (East/West) Hi Ted, A location close to a load bearing outside wall is likely to be = effected by any movements of the wall, due to rainfall on the soil = outside, the effect of the sun raising the wall temperature and also = noise from winds.=20 >What are the dimensions of the Lehman, what is the boom made of and = what is the mass? 36" boom 1/2" alum rod. Dim. 20"wide, 22" tall, 36" = long. The mass is 2.5# Alum cylinder Thanks. What is the weight of the Aluminum cylinder, please - = or alternatively it's length? Is it solid Al, 2.5" OD? Chris, I think I found the drift issue? I added a wing nut to lock = the legs after adjustment. I think they were moving over time? That could well be the problem. Threads are cut at about a 60 = degree angle and are rarely a tight fit. If the thread and the nut / = threaded insert are not of the same material, you get differential = expansion which slides the threads radially. Similarly, unless the = adjusting screw is under tension, any differential expansion of the = frame relative to the Earth underneath will try to tilt the thread and = cause it to slip diagonally. It is preferable to use a wavy spring = washer between the wing nut / lock nut and the frame to keep a fairly = constant tension. This will not be much effected by the small amounts of = differential expansion of the base and the bolt.=20 Let us know if this cures your drift problems? Regards, Chris Chapman
Hi Chris, 
 
>Is it solid Al, 2.5" = OD?   I meant to=20 say 2.5 pounds, alum 3" x 3" cylinder.
 
Ted

----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Tuesday, May 27, 2008 = 2:40 PM
Subject: Re: Adjusting the = period

In a=20 message dated 2008/05/27, tchannel1@............=20 writes:

>Is the seismometer right next to an outside = wall? =20 (Yes)

>Which direction does the wall face?=20 (East/West)

Hi=20 Ted,

       A location close to a = load=20 bearing outside wall is likely to be effected by any movements of the = wall,=20 due to rainfall on the soil outside, the effect of the sun raising the = wall=20 temperature and also noise from winds.


>What are the dimensions of the Lehman, what is the = boom made=20 of and what is the mass?  36" boom 1/2" alum rod.  Dim. = 20"wide,=20 22" tall, 36" long.  The mass is 2.5# Alum cylinder

       Thanks.=20 What is the weight of the Aluminum cylinder, please - or alternatively = it's=20 length? Is it solid Al, 2.5" OD?

Chris, I think I found the drift issue?  I added a = wing nut=20 to lock the legs after adjustment.  I think they were moving = over=20 time?

      =20 That could well be the problem. Threads are cut at about a 60 degree = angle and=20 are rarely a tight fit. If the thread and the nut / threaded insert = are not of=20 the same material, you get differential expansion which slides the = threads=20 radially. Similarly, unless the adjusting screw is under tension, any=20 differential expansion of the frame relative to the Earth underneath = will try=20 to tilt the thread and cause it to slip diagonally. It is preferable = to use a=20 wavy spring washer between the wing nut / lock nut and the frame to = keep a=20 fairly constant tension. This will not be much effected by the small = amounts=20 of differential expansion of the base and the bolt.=20

       Let us know if this cures = your=20 drift problems?

      =20 Regards,

       Chris = Chapman
=20
Subject: Big earthquake in Iceland From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 29 May 2008 16:02:19 +0000 Hi all At 15:55 there was a really big earthquake in Iceland. The size was at least ML5.5 up to ML6.1, but I am wating for better eastimate on size soon. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ping =?UTF-8?B?SsOzbiBGcsOtbWFubg==?= From: Mark Robinson mark.robinson@............... Date: Fri, 30 May 2008 04:11:57 +1200 Mag 6.1 50km from Reykjavik: http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008sqba.php The BBC was somewhat more dramatic talking about a magnitude in the high 6s. (some mail server thinks I am spamming) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ping =?UTF-8?B?SsOzbiBGcsOtbWFubg==?= From: ian ian@........... Date: Thu, 29 May 2008 17:16:37 +0100 Hi, got it here, though a low signal trace. Either my Lehman is pointing the wrong way or is was in one of its "deaf" modes again. Cheers Ian ------------------------------------------------------------------------ ------------------------------------------------------------------------ Mark Robinson wrote: > Mag 6.1 50km from Reykjavik: > > http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008sqba.php > > The BBC was somewhat more dramatic talking about a magnitude in the high 6s. > > > (some mail server thinks I am spamming) > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Big earthquake in Iceland From: Canie canie@........... Date: Thu, 29 May 2008 09:16:53 -0700 Is this quake in the area you said you were expecting a large one? It looks like it might be in that area that you=20 said was having a swarm - your note from 5/22: >Given the earthquake swarm pattern I am expecting a earthquake there >that is ML4.0 up to ML5.5, but I doubt it is going to get bigger then >mag 5.5. I expect this earthquake to happen in next two days at least, >but this might take longer time to happen. A little bigger than expected and a few days later - Good Call! Canie At 09:02 AM 5/29/2008, J=F3n Fr=EDmann wrote: >Hi all > >At 15:55 there was a really big earthquake in Iceland. The size was at >least ML5.5 up to ML6.1, but I am wating for better eastimate on size >soon. > >Regards. >-- >J=F3n Fr=EDmann >http://www.jonfr.com >http://earthquakes.jonfr.com >http://www.net303.net >http://www.mobile-coverage.com/ > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Big earthquake in Iceland From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 29 May 2008 16:30:14 +0000 Hi That area was more to the north of the current episcenter. However, the activite two the north of current epicenter might have been a clue to this earthquake. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Big earthquake in Iceland From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 29 May 2008 16:52:40 +0000 Hi all I have submitted the traces of the earthqukes to the psn web site. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: =?utf-8?Q?Re:_ping_J=C3=B3n_Fr=C3=ADmann?= From: tchannel1@............ Date: Thu, 29 May 2008 12:39:41 -0600 Hi, Got it nice and clear, here in Boise Idaho, on my Lehman pointing East and West, nothing on my vertical or North South Tiltmeter. Immg in Boise got it on their Lehman pointing North South. Ted ----- Original Message ----- From: "ian" To: Sent: Thursday, May 29, 2008 10:16 AM Subject: Re: ping Jón Frímann > Hi, > > got it here, though a low signal trace. Either my Lehman is pointing the > wrong way or is was in one of its "deaf" modes again. > > Cheers > > Ian > ------------------------------------------------------------------------ > > > > > > > > > > ------------------------------------------------------------------------ > > > > > > Mark Robinson wrote: >> Mag 6.1 50km from Reykjavik: >> >> http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008sqba.php >> >> The BBC was somewhat more dramatic talking about a magnitude in the high >> 6s. >> >> >> (some mail server thinks I am spamming) >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of >> the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> >> >> > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ping =?ISO-8859-1?Q?J=F3n?= =?ISO-8859-1?Q?_Fr=EDmann?= From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 29 May 2008 19:39:10 +0000 Hi all The movment of the earthquake was N-S, far as I can tell. I've been recording a lot of aftershocks since the big earthquake, there number of earthquakes is well above 100 and it is still going up. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Aftershocks From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 29 May 2008 23:00:37 +0000 Hi all I have started to post in traces from the aftershocks after the big earthquake today. This is just the start of it. I am still expecting a earthquake aftershock of mag 5.5 at least soon. Not sure when, but it can happen at any time. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Update on the earthquake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 30 May 2008 12:19:58 +0000 Hi all Since yesterday there have been over 1000 aftershocks and there have been new hot spring area opening up in the area close to the epicenter of the earthquake. But there is a active hot spring area near the town of Hverager=F0i. I expect the aftershocks to continue in the next few days or weeks. There might be aftershocks that might be bigger then mag 4.5. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Directional characteristics of a "lehman type" sensor- From: "Connie & Jim Lehman" lehmancj@........... Date: Fri, 30 May 2008 13:25:09 -0400 PSN friends--I have noted several references to directional performance = on a typical 15-20 sec "Lehman" design. It was our observation that = very few quakes were blocked out due to orientation. One summer when = mictoseisms are lowest (here in Virginia) we ran two systems with booms = at right angles, N-S & E-W. We copied 66 events in two months. There = were signatures in both orientations--(excepting for a half-dozen small = events) and we noted the predictable comparisons with incoming P,S, & L = wave fronts. P waves show strong coming in broadside. S waves show = strongest coming in off the end. Likewise the Surface waves -S show a = distinctive difference whether they be Love waves or Raleigh. You = simply cannot hide from a readable event due to orientation. This test was made with systems having no filtering excepting to = remove mechanical room noise typical in a building, and 60 hz AC. We = were satisfied the generalizations above were verified, as we copied = several events (Alaskan or thereabouts--coming into our booms at 45 = degrees) which appeared identical on our n-s,e-w readouts. Running two = long period systems is a luxury now, but in earlier days of the big = bulky worldwide sensors, dual copy was standard--with few stations to = get a tag on direction of event. Here in VA. we usually ran our system broadside a few degrees off E-W = to accent the events of South Pacific, but any South American events of = size would boom right in with lower P waves and heavy S wave signatures. Another side effect of noting amplitude of S or surface wave = arrivals--one can tell whether the event has a shallow focus--less than = 30 km, or a deep focus of several hundred km--even before you are told!! I hope this is informative. Jim Lehman
PSN friends--I have noted several = references to=20 directional performance on a typical 15-20 sec "Lehman" design.  It = was our=20 observation that very few quakes  were blocked out due to=20 orientation.  One summer when mictoseisms are lowest (here in = Virginia) we=20 ran two systems with booms at right angles, N-S & E-W.  We = copied 66=20 events in two months.  There were signatures in both=20 orientations--(excepting for a half-dozen small events) and we = noted the=20 predictable comparisons with incoming P,S, & L wave fronts.  P=20 waves show strong coming in broadside.  S waves show strongest = coming=20 in off the end.  Likewise the Surface waves -S show = a distinctive=20 difference whether they be Love waves or Raleigh.  You simply = cannot hide=20 from a readable event due to orientation.
   This test was made with = systems having=20 no filtering excepting to remove mechanical room noise typical in a = building, and 60 hz AC.  We were satisfied the generalizations = above were=20 verified, as we copied several events (Alaskan or thereabouts--coming = into our=20 booms at 45 degrees) which appeared identical on our n-s,e-w = readouts. =20 Running two long period systems is a luxury now, but in earlier days of = the big=20 bulky worldwide sensors, dual copy was standard--with few stations = to get a=20 tag on direction of event.
  Here in VA. we usually ran our = system=20 broadside a few degrees off E-W to accent the events of South Pacific, = but any=20 South American events of size would boom right in with lower P waves and = heavy S=20 wave signatures.
   Another side effect of = noting=20 amplitude of S or surface wave arrivals--one can tell whether the event = has a=20 shallow focus--less than 30 km, or a deep focus of several hundred = km--even=20 before you are told!!
   I hope this is = informative.  Jim=20 Lehman
   =
Subject: Re: Directional characteristics of a "lehman type" sensor- From: tchannel1@............ Date: Fri, 30 May 2008 11:46:32 -0600 Hi Jim, Thanks for this information. I have one Lehman N/S and one = E/W, and their performance agrees with your findings. There may be = differences due to orientation, but I do not see them. Ted ----- Original Message -----=20 From: Connie & Jim Lehman=20 To: psn-l@................. Sent: Friday, May 30, 2008 11:25 AM Subject: Directional characteristics of a "lehman type" sensor- PSN friends--I have noted several references to directional = performance on a typical 15-20 sec "Lehman" design. It was our = observation that very few quakes were blocked out due to orientation. = One summer when mictoseisms are lowest (here in Virginia) we ran two = systems with booms at right angles, N-S & E-W. We copied 66 events in = two months. There were signatures in both orientations--(excepting for = a half-dozen small events) and we noted the predictable comparisons with = incoming P,S, & L wave fronts. P waves show strong coming in broadside. = S waves show strongest coming in off the end. Likewise the Surface = waves -S show a distinctive difference whether they be Love waves or = Raleigh. You simply cannot hide from a readable event due to = orientation. This test was made with systems having no filtering excepting to = remove mechanical room noise typical in a building, and 60 hz AC. We = were satisfied the generalizations above were verified, as we copied = several events (Alaskan or thereabouts--coming into our booms at 45 = degrees) which appeared identical on our n-s,e-w readouts. Running two = long period systems is a luxury now, but in earlier days of the big = bulky worldwide sensors, dual copy was standard--with few stations to = get a tag on direction of event. Here in VA. we usually ran our system broadside a few degrees off = E-W to accent the events of South Pacific, but any South American events = of size would boom right in with lower P waves and heavy S wave = signatures. Another side effect of noting amplitude of S or surface wave = arrivals--one can tell whether the event has a shallow focus--less than = 30 km, or a deep focus of several hundred km--even before you are told!! I hope this is informative. Jim Lehman
Hi Jim,  Thanks for this=20 information.   I have one Lehman N/S and one E/W, and their=20 performance agrees with your findings.  There may be = differences due=20 to orientation, but I do not see them.
 
Ted
----- Original Message -----
From:=20 Connie &=20 Jim Lehman
Sent: Friday, May 30, 2008 = 11:25 AM
Subject: Directional = characteristics of a=20 "lehman type" sensor-

PSN friends--I have noted several = references to=20 directional performance on a typical 15-20 sec "Lehman" design.  = It was=20 our observation that very few quakes  were blocked out due to=20 orientation.  One summer when mictoseisms are lowest (here in = Virginia)=20 we ran two systems with booms at right angles, N-S & E-W.  We = copied=20 66 events in two months.  There were signatures in both=20 orientations--(excepting for a half-dozen small events) and we = noted the=20 predictable comparisons with incoming P,S, & L wave fronts.  = P=20 waves show strong coming in broadside.  S waves show = strongest=20 coming in off the end.  Likewise the Surface waves -S show=20 a distinctive difference whether they be Love waves or = Raleigh.  You=20 simply cannot hide from a readable event due to = orientation.
   This test was made with = systems=20 having no filtering excepting to remove mechanical room noise = typical in=20 a building, and 60 hz AC.  We were satisfied the generalizations = above=20 were verified, as we copied several events (Alaskan or = thereabouts--coming=20 into our booms at 45 degrees) which appeared identical on our n-s,e-w=20 readouts.  Running two long period systems is a luxury now, but = in=20 earlier days of the big bulky worldwide sensors, dual copy was=20 standard--with few stations to get a tag on direction of = event.
  Here in VA. we usually ran our = system=20 broadside a few degrees off E-W to accent the events of South Pacific, = but any=20 South American events of size would boom right in with lower P waves = and heavy=20 S wave signatures.
   Another side effect of = noting=20 amplitude of S or surface wave arrivals--one can tell whether the = event has a=20 shallow focus--less than 30 km, or a deep focus of several hundred = km--even=20 before you are told!!
   I hope this is = informative. =20 Jim Lehman
  =20
Subject: My sticking Lehman? From: tchannel1@............ Date: Fri, 30 May 2008 12:07:27 -0600 Hi Chris, and Others, My problems with my new Lehman, have been = resolved, I think...... I had one obvious problem: At 20 seconds the arm would drift, left or = right and I would need to reset it every two days. The legs were = threaded into the base, but loose, a lot of free play. Knowing this I = added a standard nut to lock the leg, which I would only finger tighten, = this had always worked in the past. What was happening is that the leg was moving itself. Chris pointed = out using two different materials would cause this. But on other units = it was never an issue. In this case I removed the hex nut and added a wing nut. After adj. I = finger tighten the wing nut, nice and tight, and it has not drifted = since. The second problem: At 20 seconds, I was missing all but large = earthquakes, those were coming through just fine. Chris suggest the = arm might be sticking. I could see nothing which resembled sticking. I don't know if this was the cause and effect, but I fixed it: First this is not the best Lehman I have ever built. Its okay, and with = little effort I got the 20 seconds, but I am not sure I could get 22. = However at 20 something was sticking. =20 I think at 20 it was so near infinity, it was almost flat. At infinity = it would never move to center, the arm would just stay where you placed = it. At 20 seconds it would move to center, if the event was large = enough to overcome the inertia, but smaller earthquakes would not do = this.=20 I reduce the period to 15 seconds, and it is working great. I record = 6.2M Iceland, and 4.1M California. I could, now increase the period to = 16,17,18 etc and retest. I will see how it performs at 15 for a while. Just wanted to share. Thanks for the help. Ted
Hi Chris, and Others,   My = problems with=20 my new Lehman, have been resolved, I think......
 
I had one obvious problem:   = At 20=20 seconds the arm would drift, left or right and I would need to reset it = every=20 two days.  The legs were threaded into the base, but loose, a lot = of free=20 play.  Knowing this I added a standard nut to lock the leg, which I = would=20 only finger tighten, this had always worked in the past.
 
What was happening is that the leg was = moving=20 itself.   Chris pointed out using two different materials = would cause=20 this.  But on other units it was never an issue.
In this case I removed the hex nut and = added a wing=20 nut.  After adj. I finger tighten the wing nut, nice and tight, and = it has=20 not drifted since.
 
The second problem:  At 20 = seconds, I was=20 missing all but large earthquakes, those were coming through just=20 fine.   Chris suggest the arm might be sticking.  I could = see=20 nothing which resembled sticking.
 
I don't know if this was the cause and = effect, but=20 I fixed it:
 
First this is not the best Lehman I = have ever=20 built.  Its okay, and with little effort I got the 20 seconds, but = I am not=20 sure I could get 22.  However at 20 something was sticking. =20
I think at 20 it was so near infinity, = it was=20 almost flat.   At infinity it would never move to center, = the arm=20 would just stay where you placed it.  At 20 seconds it would move = to=20 center, if the event was large enough to overcome the inertia, but = smaller=20 earthquakes would not do this.
 
I reduce the period to 15 seconds, and = it is=20 working great.  I record 6.2M Iceland, and 4.1M = California.   I=20 could, now increase the period to 16,17,18 etc and retest.   I = will=20 see how it performs at 15 for a while.
 
Just wanted to share.
 
Thanks for the help. =20 Ted
Subject: Re: 1018 steel for neo magnet damp & pickup coil web price variation From: "meredith lamb" paleoartifact@......... Date: Fri, 30 May 2008 13:15:04 -0600 Hi Gary, I went to the site and via their electronic form, asked for a quote; but after 4 days they have never replied. Perhaps like you mentioned it "maybe" primarily a local pickup source; if one has one nearby. The nearest web place I went too; their facility is a state away. Meredith On Tue, May 27, 2008 at 11:40 AM, Gary Lindgren wrote: > Meredith, > > You should also check out > http://www.metalsupermarkets.com/MSC-storefinder.aspx I ordered the steel > plates for the magnets and dimensions were very good. Very good prices too. > They also have aluminum. I'm lucky in that I have a store just a few miles > away and can pickup a day later. But they have locations around the world. > Check it out. > > Gary > > > > > > > > > Hi Gary,

I went to the site and via their electronic form, asked for a quote; but after 4 days they have never replied.  Perhaps like you mentioned
it "maybe" primarily a local pickup source; if one has one nearby.  The nearest web place I went too; their facility
is a state away.

Meredith

On Tue, May 27, 2008 at 11:40 AM, Gary Lindgren <gel@.................> wrote:

Meredith,

You should also check out http://www.metalsupermarkets.com/MSC-storefinder.aspx I ordered the steel plates for the magnets and dimensions were very good. Very good prices too. They also have aluminum. I'm lucky in that I have a store just a few miles away and can pickup a day later. But they have locations around the world. Check it out.

Gary 

 

 

 

 


Subject: Precision made; but cheapest magnet holding assembly From: "meredith lamb" paleoartifact@......... Date: Fri, 30 May 2008 14:09:50 -0600 Hi all, Actually; I think the cheapest metal magnet holding assembly, particularly for most of us without the tools to make metal plates; is to just buy a pair of machinist "1-2-3" (1" x 2" x 3") blocks from like, Discount machine on E-Bay. They cost ~$7 for a pair, plus the usual ~$10 > shipping cost. Thats 2 blocks for the one price. The more you buy in one quanity buy session; the cheaper the total shipping of course. Just add the bolts/nuts and/or spacer/standoffs for whatever you have that would work for that metal size AND whatever size magnets can fit it also. They are 1" thick x 2" height x 3" length in dimension. They have 23 holes in them; five tapped holes and 18 untapped holes. One can easily use 1/4" bolts in the untapped corner holes. They are precision ground hardened tool steel. The thickness will likely absorb most if not all magnetic effect from the mounted magnets as sensed on the opposite side/s....after all its 1" thick. As thick as they are, and with using a solid standoff/spacer, you probably won't need but 2 of such, instead of 4 bolts/nuts. If you need more magnet space (for your seismometer masterpiece/s); one can add more of the same side by side (~4 x 6, or 6 x 4") with long enough bolts/nuts to go through the pair side by side. The thickness itself makes for a extremely rigid and square overall frame and one can easily bolt it down (throught the 1" pre-drilled steel) into your seismometer base plate vertically or horizontally. On Ebay search, just enter "123 block", and you'll see them. Their is a variety of sellers over time, but Discount Machine seems the cheapest at the moment. They are probably all Tawain or China made; but the quality is much more than good enough for this purpose. Meredith Lamb Hi all,

Actually; I think the cheapest metal magnet holding assembly, particularly for most of us without the tools
to make metal plates; is to just buy a pair of machinist "1-2-3" (1" x 2" x 3") blocks from like,
Discount machine on E-Bay.  They cost ~$7 for a pair, plus the usual ~$10 > shipping cost.  Thats 2
blocks for the one price.  The more you buy in one quanity buy session; the cheaper the total shipping
of course.  Just add the bolts/nuts and/or spacer/standoffs for whatever you have that would work for
that metal size AND whatever size magnets can fit it also.

They are 1" thick x 2" height x 3" length in dimension.  They have 23 holes in them; five tapped holes and 18 untapped
holes.  One can easily use 1/4" bolts in the untapped corner holes.  They are precision ground hardened tool steel.
The thickness will likely absorb most if not all magnetic effect from the mounted magnets as sensed on the opposite
side/s....after all its 1" thick.

As thick as they are, and with using a solid standoff/spacer, you probably won't need but 2 of such, instead
of 4 bolts/nuts.

If you need more magnet space (for your seismometer masterpiece/s); one can add more of the same
side by side (~4 x 6, or 6 x 4") with long enough bolts/nuts to go through the pair side by side.

The thickness itself makes for a extremely rigid and square overall frame and one can easily bolt it down
(throught the 1" pre-drilled steel) into your seismometer base plate vertically or horizontally.

On Ebay search, just enter "123 block", and you'll see them.  Their is a variety of sellers over time, but
Discount Machine seems the cheapest at the moment.

They are probably all Tawain or China made; but the quality is much more than good enough for this
purpose.

Meredith Lamb


Subject: RE: 1018 steel for neo magnet damp & pickup coil web price variation From: "Gary Lindgren" gel@................. Date: Fri, 30 May 2008 13:32:36 -0700 Meredith, Sorry you did not get a quote reply. But you may want to check your spam folder. The quote may have dropped in there. That happened to one of my quote requests. My experience has been that a quote is answered in 15 minutes during the workday. On Tuesday I goofed on one of parts for the Lehman and sent in a quote request at 11:00AM, 15 minutes later I received a quote and liked the price and responded with OK and asked when I can pickup. Five minutes later, they said anytime to pickup. Two hours later I had the parts in hand. I would guess Metal Supermarkets is a franchise operation and each owner is his own man and how he operates. I would follow-up and make sure you get a reason for no-response. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Friday, May 30, 2008 12:15 PM To: psn-l@.............. Subject: Re: 1018 steel for neo magnet damp & pickup coil web price variation Hi Gary, I went to the site and via their electronic form, asked for a quote; but after 4 days they have never replied. Perhaps like you mentioned it "maybe" primarily a local pickup source; if one has one nearby. The nearest web place I went too; their facility is a state away. Meredith On Tue, May 27, 2008 at 11:40 AM, Gary Lindgren wrote: Meredith, You should also check out http://www.metalsupermarkets.com/MSC-storefinder.aspx I ordered the steel plates for the magnets and dimensions were very good. Very good prices too. They also have aluminum. I'm lucky in that I have a store just a few miles away and can pickup a day later. But they have locations around the world. Check it out. Gary

Meredith,

Sorry you did not get a quote reply. But you may want to = check your spam folder. The quote may have dropped in there. That happened to = one of my quote requests. My experience has been that a quote is answered in 15 = minutes during the workday. On Tuesday I goofed on one of parts for the Lehman = and sent in a quote request at 11:00AM, 15 minutes later I received a quote and = liked the price and responded with OK and asked when I can pickup. Five = minutes later, they said anytime to pickup. Two hours later I had the parts in hand. I = would guess Metal Supermarkets is a franchise operation and each owner is his = own man and how he operates. I would follow-up and make sure you get a reason = for no-response.

Gary

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Friday, May 30, 2008 12:15 PM
To: psn-l@..............
Subject: Re: 1018 steel for neo magnet damp & pickup coil web = price variation

 

Hi Gary,

I went to the site and via their electronic form, asked for a quote; but = after 4 days they have never replied.  Perhaps like you mentioned
it "maybe" primarily a local pickup source; if one has one nearby.  The nearest web place I went too; their facility
is a state away.

Meredith

 

Subject: RE: Precision made; but cheapest magnet holding assembly From: "Gary Lindgren" gel@................. Date: Fri, 30 May 2008 13:54:50 -0700 Meredith, Your thought that maybe the 1-2-3 blocks are made in China reminded me that a few weeks ago I was looking for a coil winder on eBay and found one that looked good. Only $35 and it comes from China. The shipping is costly at $60, but 3 days later I had it in my hand. Oh that globalization thing!!! Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Friday, May 30, 2008 1:10 PM To: psn-l@.............. Subject: Precision made; but cheapest magnet holding assembly Hi all, Actually; I think the cheapest metal magnet holding assembly, particularly for most of us without the tools to make metal plates; is to just buy a pair of machinist "1-2-3" (1" x 2" x 3") blocks from like, Discount machine on E-Bay. They cost ~$7 for a pair, plus the usual ~$10 > shipping cost. Thats 2 blocks for the one price. The more you buy in one quanity buy session; the cheaper the total shipping of course. Just add the bolts/nuts and/or spacer/standoffs for whatever you have that would work for that metal size AND whatever size magnets can fit it also. They are 1" thick x 2" height x 3" length in dimension. They have 23 holes in them; five tapped holes and 18 untapped holes. One can easily use 1/4" bolts in the untapped corner holes. They are precision ground hardened tool steel. The thickness will likely absorb most if not all magnetic effect from the mounted magnets as sensed on the opposite side/s....after all its 1" thick. As thick as they are, and with using a solid standoff/spacer, you probably won't need but 2 of such, instead of 4 bolts/nuts. If you need more magnet space (for your seismometer masterpiece/s); one can add more of the same side by side (~4 x 6, or 6 x 4") with long enough bolts/nuts to go through the pair side by side. The thickness itself makes for a extremely rigid and square overall frame and one can easily bolt it down (throught the 1" pre-drilled steel) into your seismometer base plate vertically or horizontally. On Ebay search, just enter "123 block", and you'll see them. Their is a variety of sellers over time, but Discount Machine seems the cheapest at the moment. They are probably all Tawain or China made; but the quality is much more than good enough for this purpose. Meredith Lamb

Meredith,

Your thought that maybe the 1-2-3 blocks are made in = China reminded me that a few weeks ago I was looking for a coil winder on eBay = and found one that looked good. Only $35 and it comes from China. The = shipping is costly at $60, but 3 days later I had it in my hand. Oh that = globalization thing!!!

Gary

 

 

 

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Friday, May 30, 2008 1:10 PM
To: psn-l@..............
Subject: Precision made; but cheapest magnet holding = assembly

 

Hi all,

Actually; I think the cheapest metal magnet holding assembly, = particularly for most of us without the tools
to make metal plates; is to just buy a pair of machinist = "1-2-3" (1" x 2" x 3") blocks from like,
Discount machine on E-Bay.  They cost ~$7 for a pair, plus the = usual ~$10 > shipping cost.  Thats 2
blocks for the one price.  The more you buy in one quanity buy = session; the cheaper the total shipping
of course.  Just add the bolts/nuts and/or spacer/standoffs for = whatever you have that would work for
that metal size AND whatever size magnets can fit it also.

They are 1" thick x 2" height x 3" length in = dimension.  They have 23 holes in them; five tapped holes and 18 untapped
holes.  One can easily use 1/4" bolts in the untapped corner holes.  They are precision ground hardened tool steel.
The thickness will likely absorb most if not all magnetic effect from = the mounted magnets as sensed on the opposite
side/s....after all its 1" thick.

As thick as they are, and with using a solid standoff/spacer, you = probably won't need but 2 of such, instead
of 4 bolts/nuts.

If you need more magnet space (for your seismometer masterpiece/s); one = can add more of the same
side by side (~4 x 6, or 6 x 4") with long enough bolts/nuts to go = through the pair side by side.

The thickness itself makes for a extremely rigid and square overall = frame and one can easily bolt it down
(throught the 1" pre-drilled steel) into your seismometer base = plate vertically or horizontally.

On Ebay search, just enter "123 block", and you'll see = them.  Their is a variety of sellers over time, but
Discount Machine seems the cheapest at the moment.

They are probably all Tawain or China made; but the quality is much more = than good enough for this
purpose.

Meredith Lamb

Subject: RE: 1018 steel for neo magnet damp & pickup coil web price variation From: "Gary Lindgren" gel@................. Date: Fri, 30 May 2008 14:18:09 -0700 Meredith, Send your RFQ to bill@................. Bill is my Metal Supermarkets contact at the Redwood City CA shop. They make local deliveries with their truck and ship via UPS or common carrier. You still have a couple hours for a quote today. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Friday, May 30, 2008 12:15 PM To: psn-l@.............. Subject: Re: 1018 steel for neo magnet damp & pickup coil web price variation Hi Gary, I went to the site and via their electronic form, asked for a quote; but after 4 days they have never replied. Perhaps like you mentioned it "maybe" primarily a local pickup source; if one has one nearby. The nearest web place I went too; their facility is a state away. Meredith On Tue, May 27, 2008 at 11:40 AM, Gary Lindgren wrote: Meredith, You should also check out http://www.metalsupermarkets.com/MSC-storefinder.aspx I ordered the steel plates for the magnets and dimensions were very good. Very good prices too. They also have aluminum. I'm lucky in that I have a store just a few miles away and can pickup a day later. But they have locations around the world. Check it out. Gary

Meredith,

Send your RFQ to bill@................. Bill = is my Metal Supermarkets contact at the Redwood City CA shop. They make local = deliveries with their truck and ship via UPS or common carrier. You still have a = couple hours for a quote today.

Gary

 

 

 

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Friday, May 30, 2008 12:15 PM
To: psn-l@..............
Subject: Re: 1018 steel for neo magnet damp & pickup coil web = price variation

 

Hi Gary,

I went to the site and via their electronic form, asked for a quote; but = after 4 days they have never replied.  Perhaps like you mentioned
it "maybe" primarily a local pickup source; if one has one = nearby.  The nearest web place I went too; their facility
is a state away.

Meredith

 

Subject: Update on the earthquake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 30 May 2008 21:59:24 +0000 Hi all Here are some data that I have collected since yesterday earthquake. This is mostly traces along side maps from IMO that I have saved for keeping. http://www.jonfr.com/myndir/v/geology/sisz2008/ Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My sticking Lehman? From: ChrisAtUpw@....... Date: Fri, 30 May 2008 18:53:30 EDT In a message dated 2008/05/30, tchannel1@............ writes: > The second problem: At 20 seconds, I was missing all but large > earthquakes, those were coming through just fine. Chris suggest the arm might be > sticking. I could see nothing which resembled sticking. Hi Ted, 1) what top bearing / flexure are you using? 2) what bottom bearing / flexure are you using? 3) have you checked both the coil and the damping magnets for whiskers? They tend to grow with time and can cause the beam to stick. I use one of the pen lasers to check that the gaps are clear. > I don't know if this was the cause and effect, but I fixed it: > > First this is not the best Lehman I have ever built. Its okay, and with > little effort I got the 20 seconds, but I am not sure I could get 22. However > at 20 something was sticking. > I think at 20 it was so near infinity, it was almost flat. At infinity it > would never move to center, the arm would just stay where you placed it. At 20 > seconds it would move to center, if the event was large enough to overcome > the inertia, but smaller earthquakes would not do this. This is typical of a problem with the suspension system. I don't know what you expected to 'see', but you have just given a good description of what is observed. I suspect that you will not have fixed the problem by shortening the period, just reduced it a bit. The stiction, from whatever cause, will still be there. > I reduce the period to 15 seconds, and it is working great. I record 6.2M > Iceland, and 4.1M California. I could, now increase the period to 16,17,18 > etc and retest. I will see how it performs at 15 for a while. Regards, Chris Chapman In a me= ssage dated 2008/05/30, tchannel1@............ writes:

The second problem:  At 20= seconds, I was missing all but large earthquakes, those were coming through= just fine. Chris suggest the arm might be sticking.  I could see nothi= ng which resembled sticking.


Hi Ted,

       1) what top bearing / flexure are you u= sing?
       2) what bottom bearing / flexure are yo= u using?
       3) have you checked both the coil and t= he damping magnets for whiskers? They tend to grow with time and can cause t= he beam to stick. I use one of the pen lasers to check that the gaps are cle= ar.


I don't know if this was the c= ause and effect, but I fixed it:

First this is not the best Lehman I have ever built.  Its okay, and wi= th little effort I got the 20 seconds, but I am not sure I could get 22.&nbs= p; However at 20 something was sticking. 
I think at 20 it was so near infinity, it was almost flat. At infinity it w= ould never move to center, the arm would just stay where you placed it. At 2= 0 seconds it would move to center, if the event was large enough to overcome= the inertia, but smaller earthquakes would not do this.


       This is typical of a problem with the=20= suspension system. I don't know what you expected to 'see', but you have jus= t given a good description of what is observed. I suspect that you will not=20= have fixed the problem by shortening the period, just reduced it a bit. The=20= stiction, from whatever cause, will still be there.

I reduce the period to 15 seco= nds, and it is working great.  I record 6.2M Iceland, and 4.1M Californ= ia.   I could, now increase the period to 16,17,18 etc and retest.=    I will see how it performs at 15 for a while.


       Regards,

       Chris Chapman
Subject: Re: Precision made; but cheapest magnet holding assembly From: ChrisAtUpw@....... Date: Sat, 31 May 2008 00:02:20 EDT In a message dated 2008/05/30, paleoartifact@......... writes: > Actually; I think the cheapest metal magnet holding assembly, particularly > for most of us without the tools to make metal plates; is to just buy a pair > of machinist "1-2-3" (1" x 2" x 3") blocks from like, Discount machine on > E-Bay. Hi Meredith, These are hardened steel blocks. They will have a significantly lower permeability than mild steel. I first tried using annealed high carbon steel - called gauge plate - you can buy it in a wide range of sizes, but I reverted to mild steel. We can get hold of the 2" x 1/4" mild steel strip through outlets serving the building trade - it is used for reinforcing / joining wood beams and also for load bearing lintels. Hinges for farm gates are bent from this. Regards, Chris In a me= ssage dated 2008/05/30, paleoartifact@......... writes:

Actually; I think the cheapest=20= metal magnet holding assembly, particularly for most of us without the tools= to make metal plates; is to just buy a pair of machinist "1-2-3" (1" x 2" x= 3") blocks from like, Discount machine on E-Bay.


Hi Meredith,

       These are hardened steel blocks. They w= ill have a significantly lower permeability than mild steel. I first tried u= sing annealed high carbon steel - called gauge plate - you can buy it in a w= ide range of sizes, but I reverted to mild steel.

       We can get hold of the 2" x 1/4" mild s= teel strip through outlets serving the building trade - it is used for reinf= orcing / joining wood beams and also for load bearing lintels. Hinges for fa= rm gates are bent from this.

       Regards,

       Chris
Subject: Re: My sticking Lehman? From: tchannel1@............ Date: Fri, 30 May 2008 17:07:26 -0600 Thanks, Chris, ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Friday, May 30, 2008 4:53 PM Subject: Re: My sticking Lehman? In a message dated 2008/05/30, tchannel1@............ writes: The second problem: At 20 seconds, I was missing all but large = earthquakes, those were coming through just fine. Chris suggest the arm = might be sticking. I could see nothing which resembled sticking. Hi Ted, 1) what top bearing / flexure are you using? (The top hinge = is a SS wire, don't know the dia. but very thin.) 2) what bottom bearing / flexure are you using? (The bottom = is a ball bearing on sidebyside drill bit shanks.)(this I think could be = my weakest point, this arrangement may not be good enough) (I may = rework this) 3) have you checked both the coil and the damping magnets for = whiskers? They tend to grow with time and can cause the beam to stick. I = use one of the pen lasers to check that the gaps are clear. Not sure = what whiskers are............but it is a new machine. I don't know if this was the cause and effect, but I fixed it: First this is not the best Lehman I have ever built. Its okay, and = with little effort I got the 20 seconds, but I am not sure I could get = 22. However at 20 something was sticking. =20 I think at 20 it was so near infinity, it was almost flat. At = infinity it would never move to center, the arm would just stay where = you placed it. At 20 seconds it would move to center, if the event was = large enough to overcome the inertia, but smaller earthquakes would not = do this. This is typical of a problem with the suspension system. I = don't know what you expected to 'see', but you have just given a good = description of what is observed. I suspect that you will not have fixed = the problem by shortening the period, just reduced it a bit. The = stiction, from whatever cause, will still be there. I reduce the period to 15 seconds, and it is working great. I = record 6.2M Iceland, and 4.1M California. I could, now increase the = period to 16,17,18 etc and retest. I will see how it performs at 15 = for a while. Regards, Chris Chapman
Thanks, Chris,
----- Original Message -----
From:=20
ChrisAtUpw@.......
Sent: Friday, May 30, 2008 4:53 = PM
Subject: Re: My sticking = Lehman?

In a=20 message dated 2008/05/30, tchannel1@............=20 writes:

The second problem:  At 20 seconds, I was missing = all but=20 large earthquakes, those were coming through just fine. Chris = suggest the=20 arm might be sticking.  I could see nothing which resembled=20 sticking.


Hi=20 Ted,

       1) what top bearing / = flexure=20 are you using?    (The top hinge is a SS wire, don't = know the=20 dia.  but very = thin.)
       2)=20 what bottom bearing / flexure are you using?   (The bottom = is a ball=20 bearing on sidebyside drill bit shanks.)(this I think could be my = weakest=20 point, this arrangement may not be good enough)  (I may rework=20 this)
       3) have you checked both = the=20 coil and the damping magnets for whiskers? They tend to grow with time = and can=20 cause the beam to stick. I use one of the pen lasers to check that the = gaps=20 are clear.   Not sure what whiskers are............but it is = a new=20 machine.


I don't know if this was the cause and effect, but I = fixed=20 it:

First this is not the best Lehman I have ever = built. =20 Its okay, and with little effort I got the 20 seconds, but I am not = sure I=20 could get 22.  However at 20 something was sticking.  =
I think at 20 it = was so near=20 infinity, it was almost flat. At infinity it would never move to = center, the=20 arm would just stay where you placed it. At 20 seconds it would move = to=20 center, if the event was large enough to overcome the inertia, but = smaller=20 earthquakes would not do this.

       This is=20 typical of a problem with the suspension system. I don't know what you = expected to 'see', but you have just given a good description of what = is=20 observed. I suspect that you will not have fixed the problem by = shortening the=20 period, just reduced it a bit. The stiction, from whatever cause, will = still=20 be there.

I reduce the period to 15 seconds, and it is working=20 great.  I record 6.2M Iceland, and 4.1M California.   = I=20 could, now increase the period to 16,17,18 etc and = retest.   I=20 will see how it performs at 15 for a while.

      =20 Regards,

       Chris = Chapman
=20
Subject: Re: My sticking Lehman? From: ChrisAtUpw@....... Date: Sat, 31 May 2008 14:12:17 EDT In a message dated 2008/05/31, tchannel1@............ writes: Hi Ted, > 1) what top bearing / flexure are you using? (The top hinge is a > SS wire, don't know the dia. but very thin.) That should be OK, so long as the wire is hard drawn and 'very springy'. Annealed wire needs to be pulled / drawn to harden it. I usually use nickel plated music wire. It is cheap, readily available and it is quite rust resistant. > 2) what bottom bearing / flexure are you using? (The bottom is a > ball bearing on sidebyside drill bit shanks.)(this I think could be my weakest > point, this arrangement may not be good enough) (I may rework this) Sorry, I remember now. Ordinary drill shanks are unlikely to last long, due to friction corrosion. I use a SS ball on a SS scalpel blade glued to the end of an Al alloy arm with acrylic glue. I can set this for 30 seconds without any problem. I suspect that a loaded ball rolling on two cylinders may have a small amount of rolling friction. It will tend to try to push the drills apart. You can also used the crossed shanks of two tungsten carbide drills, used commercially and for drilling glass circuit board. > 3) have you checked both the coil and the damping magnets for > whiskers? They tend to grow with time and can cause the beam to stick. I use one of > the pen lasers to check that the gaps are clear. Not sure what whiskers > are............but it is a new machine. Shine a light into the magnet gaps and view from right angles or the far side, preferably with a magnifying glass. Whiskers are literally that - tiny hair like strings of magnetic particles sticking up ~at right angles to the edges / surfaces of the magnets. They can be quite difficult to see, but they grow with time from dust in the air. A laser pen will show them up clearly. I use Gaffer Tape / Duct Tape to remove them. It has a rubber adhesive on a loose woven backing strip which is particularly good at removing grit, dust and swarf. You press it on firmly all over the magnet surfaces / edges and then peel it off. From bitter experience, if you HAVEN'T cleaned your magnets this way, they are VERY LIKELY to have whiskers. I always clean the magnets during assembly and check them again after mounting them in place. Do CHECK !! Regards, Chris Chapman In a me= ssage dated 2008/05/31, tchannel1@............ writes:

Hi Ted,

     &= nbsp; 1) what top bearing / flexure are you using?    (The to= p hinge is a SS wire, don't know the dia.  but very thin.)

       That should be OK, so long as the wire= is hard drawn and 'very springy'. Annealed wire needs to be pulled / drawn=20= to harden it. I usually use nickel plated music wire. It is cheap, readily a= vailable and it is quite rust resistant.

     &= nbsp; 2) what bottom bearing / flexure are you using?   (The botto= m is a ball bearing on sidebyside drill bit shanks.)(this I think could be m= y weakest point, this arrangement may not be good enough)  (I may rewor= k this)


       Sorry, I remember now. Ordinary drill=20= shanks are unlikely to last long, due to friction corrosion. I use a SS ball= on a SS scalpel blade glued to the end of an Al alloy arm with acrylic glue= .. I can set this for 30 seconds without any problem. I suspect that a loaded= ball rolling on two cylinders may have a small amount of rolling friction.=20= It will tend to try to push the drills apart.

       You can also used the crossed shanks of= two tungsten carbide drills, used commercially and for drilling glass circu= it board.


     &= nbsp; 3) have you checked both the coil and the damping magnets for whiskers= ? They tend to grow with time and can cause the beam to stick. I use one of=20= the pen lasers to check that the gaps are clear.   Not sure what w= hiskers are............but it is a new machine.


       Shine a light into the magnet gaps and=20= view from right angles or the far side, preferably with a magnifying glass.=20= Whiskers are literally that - tiny hair like strings of magnetic particles s= ticking up ~at right angles to the edges / surfaces of the magnets. They can= be quite difficult to see, but they grow with time from dust in the air. A=20= laser pen will show them up clearly.

       I use Gaffer Tape / Duct Tape to remove= them. It has a rubber adhesive on a loose woven backing strip which is part= icularly good at removing grit, dust and swarf. You press it on firmly all o= ver the magnet surfaces / edges and then peel it off.

       From bitter experience, if you HAVEN'T=20= cleaned your magnets this way, they are VERY LIKELY to have whiskers. I alwa= ys clean the magnets during assembly and check them again after mounting the= m in place. Do CHECK !!

       Regards,

       Chris Chapman
Subject: Re: Precision made; but cheapest magnet holding assembly From: "meredith lamb" paleoartifact@......... Date: Sat, 31 May 2008 12:35:17 -0600 Hi Chris, I quite readily agree with you; that they are a very lower grade steel for the much higher desirable permeability aspect. Those that can; will indeed get better iron/steel. Personally, I've got all the even much better iron/steel, and I don't need any improvements in such material for myself. They are a "beginner" recommendation I think that would work more immediately in their "first step" more simpler seismometer projects. I'll try to express myself better in the future. In the basic sense of a usual "typical very small or 3rd world budget" (read it as a high failure rate for most individuals in their often brief seismology hobby interest) approach; they are relatively impossible to beat economically price wise, immediate much wider range of mechanically functionally and still get useful results in coil pickup and dampening needs. I would guess; they are probably size limited to their usefulness to seismometers where the vertical or horizontal mass is light weight like around 1 pound; but even here the very choice of the neodymium magnet dimension size, and their very choice of the grade of the magnet used will likely have a dramatic impact on the results observed. There is alot of other problems in seismometry construction; but hopefully this could reduce one piece. I have the highest regard for your extensive professional knowledge and opinions Chris; which I think most people are very grateful and appreciative for. Take care, Meredith Lamb On Fri, May 30, 2008 at 10:02 PM, wrote: > In a message dated 2008/05/30, paleoartifact@......... writes: > > Actually; I think the cheapest metal magnet holding assembly, particularly > for most of us without the tools to make metal plates; is to just buy a pair > of machinist "1-2-3" (1" x 2" x 3") blocks from like, Discount machine on > E-Bay. > > > > Hi Meredith, > > These are hardened steel blocks. They will have a significantly > lower permeability than mild steel. I first tried using annealed high carbon > steel - called gauge plate - you can buy it in a wide range of sizes, but I > reverted to mild steel. > > We can get hold of the 2" x 1/4" mild steel strip through outlets > serving the building trade - it is used for reinforcing / joining wood beams > and also for load bearing lintels. Hinges for farm gates are bent from this. > > > Regards, > > Chris Hi Chris,

I quite readily agree with you; that they are a very lower grade steel for the much higher desirable permeability aspect.  Those that can; will indeed get better iron/steel.
Personally, I've got all the even much better iron/steel, and I don't need any improvements in such material for myself.  They are a "beginner" recommendation I think
that would work more immediately in their "first step" more simpler seismometer projects.  I'll try to express myself better in the future.

In the basic sense of a usual "typical very small or 3rd world budget" (read it as a high failure rate for most individuals in their often brief seismology hobby interest)
approach; they are relatively impossible to beat economically price wise, immediate much wider range of mechanically functionally and still get useful results
in coil pickup and dampening needs.  I would guess; they are probably size limited to their usefulness to seismometers where the vertical or horizontal mass is
light weight like around 1 pound; but even here the very choice of the neodymium magnet dimension size, and their very choice of the grade of the magnet used
will likely have a dramatic impact on the results observed.  There is alot of other problems in seismometry construction; but hopefully this could reduce one piece.

I have the highest regard for your extensive professional knowledge and opinions Chris; which I think most people are very grateful and appreciative for.

Take care, Meredith Lamb

 

 

On Fri, May 30, 2008 at 10:02 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/05/30, paleoartifact@......... writes:

Actually; I think the cheapest metal magnet holding assembly, particularly for most of us without the tools to make metal plates; is to just buy a pair of machinist "1-2-3" (1" x 2" x 3") blocks from like, Discount machine on E-Bay.


Hi Meredith,

       These are hardened steel blocks. They will have a significantly lower permeability than mild steel. I first tried using annealed high carbon steel - called gauge plate - you can buy it in a wide range of sizes, but I reverted to mild steel.

       We can get hold of the 2" x 1/4" mild steel strip through outlets serving the building trade - it is used for reinforcing / joining wood beams and also for load bearing lintels. Hinges for farm gates are bent from this.

       Regards,

       Chris

Subject: Re: Pivot balls; carbide and corundum reminder From: ChrisAtUpw@....... Date: Sat, 7 Jun 2008 16:02:21 EDT In a message dated 07/06/2008, gel@................. writes: Small Parts Inc. stocks carbide, synthetic ruby (red) and sapphire (clear) balls that could probably replace (and very likely enhance the pivot) of your steel ball bearings in your seismometer pivots. The corundum sizes range from 1/64" up to 1/8" @ $3.45 up to $4.00 each. You can buy in quanity somewhat cheaper. The sphericity (roundness) listed is 0.000025". _http://www.smallparts.com/products/descriptions/brb.cfm_ (http://www.smallparts.com/products/descriptions/brb.cfm) _http://www.smallparts.com/products/descriptions/BSP.cfm_ (http://www.smallparts.com/products/descriptions/BSP.cfm) The tungsten carbide balls range from 1/16" up to 1/2" @ $3.25 up to $16.80 each. They have metric sizes also. The sphericity listed is 0.0006"...quite abit less round than the corundum. Hi Meredith, Hardness is no the only criterion. You also need high shear and compressive strengths to prevent chipping around the contact point. 1/8" OD ball is a bit small in my opinion for a ~2 kg axial load, common on Lehmans. I would be happier with 3/8" ~ 1/2" OD. The surface needs to be highly polished. I doubt if a sphericity of 0.0006" is at all limiting. You also need hard polished flats for the bearing to roll on. What is available, please? With a 22" arm, I get a period >30 seconds quite easily with a 1/2" SS bearing ball and a SS flat cut from a scalpel blade glued to the end of the Al arm. Regards, Chris Chapman
In a message dated 07/06/2008, gel@................. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3D"Times New Roman" color=3D#= 000000=20 size=3D3>Small Parts Inc. stocks carbide, synthetic ruby (red) and sapphir= e=20 (clear) balls that could probably replace (and very likely enhance the piv= ot)=20 of your steel ball bearings in your seismometer pivots. 

The=20 corundum sizes range from 1/64" up to 1/8" @ $3.45 up to $4.00 each. = You=20 can buy in
quanity somewhat cheaper.  The sphericity (roundness)=20 listed is 0.000025".

http://www.smallparts.com/products/descriptions/brb.cfm
http://www.smallparts.com/products/descriptions/BSP.cfm

The=20 tungsten carbide balls range from 1/16" up to 1/2" @ $3.25 up to $16.80=20 each.  They
have metric sizes also.  The sphericity listed is= =20 0.0006"...quite abit less round than the corundum.
=
Hi Meredith,
 
    Hardness is no the only criterion. You also=20 need high shear and compressive strengths to prevent chipping around th= e=20 contact point. 1/8" OD ball is a bit small in my opinion for a ~2 kg axial l= oad,=20 common on Lehmans. I would be happier with 3/8" ~ 1/2" OD. The surface needs= to=20 be highly polished. I doubt if a sphericity of 0.0006" is at all limiting.
 
    You also need hard polished flats for the beari= ng=20 to roll on. What is available, please?
 
    With a 22" arm, I get a period >30 seconds q= uite=20 easily with a 1/2" SS bearing ball and a SS flat cut from a scalpel blade gl= ued=20 to the end of the Al arm.
 
    Regards,
 
    Chris Chapman
 
Subject: RE: Pivot balls; carbide and corundum reminder From: "Gary Lindgren" gel@................. Date: Sat, 7 Jun 2008 14:44:03 -0700 Meredith, Here is another reference for ceramic ball bearings. http://www.parktool.com/repair/readcalvinscorner.asp?id=170 The VXB bearings are grade 5, that is much more round than the Small Parts bearings. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Saturday, June 07, 2008 10:04 AM To: psn-l@.............. Subject: Pivot balls; carbide and corundum reminder Hi all, Small Parts Inc. stocks carbide, synthetic ruby (red) and sapphire (clear) balls that could probably replace (and very likely enhance the pivot) of your steel ball bearings in your seismometer pivots. The corundum sizes range from 1/64" up to 1/8" @ $3.45 up to $4.00 each. You can buy in quanity somewhat cheaper. The sphericity (roundness) listed is 0.000025". http://www.smallparts.com/products/descriptions/brb.cfm http://www.smallparts.com/products/descriptions/BSP.cfm The tungsten carbide balls range from 1/16" up to 1/2" @ $3.25 up to $16.80 each. They have metric sizes also. The sphericity listed is 0.0006"...quite abit less round than the corundum. http://www.smallparts.com/products/descriptions/btc.CFM The "big bite" of it all is their shipping/handling costs ~ $14.00 (USA) irregardless of the small weight. Their FedEx "2 day" shipping could be up to 4-5 days. Ground shipping ~ 7 to 10 or more days. Take care, Meredith

Meredith,

Here is another reference for ceramic ball bearings. ht= tp://www.parktool.com/repair/readcalvinscorner.asp?id=3D170  The VXB bearings are grade 5, that is much more round than the Small = Parts bearings.

Gary

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Saturday, June 07, 2008 10:04 AM
To: psn-l@..............
Subject: Pivot balls; carbide and corundum = reminder

 

Hi all,

Small Parts Inc. stocks carbide, synthetic ruby (red) and sapphire = (clear) balls that could probably
replace (and very likely enhance the pivot) of your steel ball bearings = in your seismometer pivots. 

The corundum sizes range from 1/64" up to 1/8" @ $3.45 up to = $4.00 each.  You can buy in
quanity somewhat cheaper.  The sphericity (roundness) listed is 0.000025".

http://www.smallparts.com/products/descriptions/brb.cfm=
http://www.smallparts.com/products/descriptions/BSP.cfm=

The tungsten carbide balls range from 1/16" up to 1/2" @ $3.25 = up to $16.80 each.  They
have metric sizes also.  The sphericity listed is = 0.0006"...quite abit less round than the corundum.

http://www.smallparts.com/products/descriptions/btc.CFM=

The "big bite" of it all is their shipping/handling costs ~ = $14.00 (USA) irregardless of the small weight.
Their FedEx "2 day" shipping could be up to 4-5 days.  = Ground shipping ~ 7 to 10 or more days.

Take care, Meredith
 


Subject: Adjusting Lehman Resonant Period From: "Gary Lindgren" gel@................. Date: Sat, 7 Jun 2008 15:53:27 -0700 I'm the process of adjusting the resonant period of my first Lehman seismometer. Are there other parameters besides the angle that I should be aware in achieving a long period. How about the position of the mass, should I move the mass towards the end of the pendulum. This assumes I have a good mounting method for the support wire and a low friction bearing. Thank you, Gary Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 650-326-0655 www.blue-eagle-technologies.com cymonsplace.blogspot.com

I’m the process of adjusting the resonant = period of my first Lehman seismometer. Are there other parameters besides the angle = that I should be aware in achieving a long period. How about the position of = the mass, should I move the mass towards the end of the pendulum. This assumes I = have a good mounting method for the support wire and a low friction = bearing.

Thank you,

Gary

 

 

 

 

 

 

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

 

650-326-0655<= /span>

 

www.blue-eagle-technologies.com

cymonsplace.blogspot.com 

 

 

Subject: RE: Concrete Block framework for horizontal sensor. From: "Paul Cianciolo" Paulc@........ Date: Sat, 7 Jun 2008 18:57:59 -0400 Hello Chris, Thank you for the information. I would not use aggregate, just a sand mix if build it from scratch. Maybe the whole idea is more trouble than it is worth. I am using the AL plates right now as you suggested. Maybe I should just leave the frame construction alone and concentrate getting the sensor back up and running. I didn't realize that concrete was so porous. Epoxy is not my glue of choice for lots of my different projects now. I have actually had it shatter and have bit shard of it embed in my skin. Thanks again for the advice. PauLC -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of ChrisAtUpw@....... Sent: Friday, June 06, 2008 4:39 PM To: psn-l@.............. Subject: Re: Concrete Block framework for horizontal sensor. In a message dated 06/06/2008, Paulc@........ writes: I wonder if anyone has had any experience using standard concrete blocks to form the "L" framework for a horizontal sensor. Hi Paul, Ordinary concrete with stone aggregate in it can be quite noisy as the temperature changes. The expansion coefficients of the cement and the stones are different. For seismic use, a 50:50 mix of sand and cement is recommended - definitely no aggregate! >> For the pivots I would be using crossed rods top and bottom. I would cement in place the mounts for these and make the top adjustable for levelling.This amounts to taking my horizontal sensor which constructed on an AL channel frame, and moving it over to the concrete frame. I have the space to do this. You will need to cover the concrete and keep it wet for at least a fortnight to cure. Then allow it to dry out slowly and coat it with a sealing paint - concrete can absorb quite a lot of water as the humidity changes. Damp concrete can be very corrosive to metals. I am doubtful about trying to cement the mounts in place. They are usually secured with bolts. Concrete takes compressive forces OK, but it is not strong in tension and it does not adhere well to metals. Adhesives are generally used. The aluminum frame is currently apart and was being readied for welding. Why weld the Al U channel frame at all? I use 1/8" thick triangular Al plates and 4 stainless steel bolts to secure the corners. This is simple to do and works well. Welding Al can be OK, but you have to know your alloys - not all of them weld well and quite a bit of skill is required. Welded joints also have a lot of stress frozen in, which can cause problems if it is not relieved. Welded metal is usually quite soft. You stress relieve the joints at 180 C for maybe an hour. Any comments or suggestions.? You can also stick Al frame components together with two part acrylic adhesives. Don't try to use Epoxy. Al sticks better if it is heated first to drive off the water absorbed on the surface. Regards, Chris Chapman
Hello=20 Chris,
 
Thank you = for the=20 information.  I would not use aggregate, just a sand mix if build = it from=20 scratch.
Maybe the = whole idea is=20 more trouble than it is worth.
I am using = the AL plates=20 right now as you suggested.  Maybe I should just leave the frame=20 construction alone and concentrate getting the sensor back up and=20 running.
 
I didn't = realize that=20 concrete was so porous.  Epoxy is not my glue of choice for lots of = my=20 different projects now.
I have = actually had it=20 shatter and have bit shard of it embed in my skin.  =
 
Thanks again = for the=20 advice.
 
PauLC
 
-----Original Message-----
From:=20 psn-l-request@.............. = [mailto:psn-l-request@...............On Behalf=20 Of ChrisAtUpw@.......
Sent: Friday, June 06, 2008 4:39=20 PM
To: psn-l@..............
Subject: Re: Concrete = Block=20 framework for horizontal sensor.

In a message dated 06/06/2008, Paulc@........ writes:
I wonder if anyone has had any = experience using standard concrete blocks to form the "L" = framework for=20 a horizontal sensor.
Hi Paul,
 
    Ordinary concrete with stone aggregate in = it can=20 be quite noisy as the temperature changes. The expansion coefficients = of the=20 cement and the stones are different. For seismic use, a 50:50 mix of = sand and=20 cement is recommended - definitely no aggregate!
 
>>    For the = pivots I=20 would be using crossed rods top and bottom.  I would cement in = place the=20 mounts for these and make the top adjustable for = levelling.This amounts to taking my horizontal sensor = which=20 constructed on an AL channel frame, and moving it over to the concrete = frame.  I have the space to do this.
 
    You will=20 need to cover the concrete and keep it wet for at least a fortnight to = cure.=20 Then allow it to dry out slowly and coat it with a sealing paint = -=20 concrete can absorb quite a lot of water as the humidity changes. Damp = concrete can be very corrosive to metals.
    I am=20 doubtful about trying to cement the mounts in place. They are usually = secured=20 with bolts. Concrete takes compressive forces OK, but it is not strong = in=20 tension and it does not adhere well to metals. Adhesives are generally = used.
The aluminum frame is = currently apart=20 and was being readied for welding.
    Why weld the Al U channel frame at all? I = use=20 1/8" thick triangular Al plates and 4 stainless steel bolts to secure = the=20 corners. This is simple to do and works well.
    Welding Al can be OK, but you have to = know your=20 alloys - not all of them weld well and quite a bit of skill is = required.=20 Welded joints also have a lot of stress frozen in, which can cause = problems if=20 it is not relieved. Welded metal is usually quite soft. You = stress=20 relieve the joints at 180 C for maybe an hour.
Any comments or=20 suggestions.?
    You can also stick Al frame components = together=20 with two part acrylic adhesives. Don't try to use Epoxy. Al sticks = better if=20 it is heated first to drive off the water absorbed on the = surface.
 
    Regards,
 
    Chris Chapman
 
 
Subject: Re: Adjusting Lehman Resonant Period From: ChrisAtUpw@....... Date: Sat, 7 Jun 2008 19:50:23 EDT =20 In a message dated 07/06/2008, gel@................. writes: I=E2=80=99m the process of adjusting the resonant period of my first Lehman= =20 seismometer. Are there other parameters besides the angle that I should be=20= aware in=20 achieving a long period. How about the position of the mass, should I move=20= the=20 mass towards the end of the pendulum. This assumes I have a good mounting=20 method for the support wire and a low friction bearing. Hi Gary, =20 You can use C of G mass to pivot lengths between about 1and 3 ft. The=20 longer lengths are easier to set up and to adjust. With short lengths you a= re=20 very sensitive to ground tilt variations. The increase in period with lengt= h=20 is low above 3 ft and the arm becomes difficult to make rigid and the=20 temperature + air movements (noise) more difficult to control / reduce. If=20= you wanted=20 a vertical pendulum with a 4 second period, you would need a 12 ft long=20 arm... I use a V support wire made from SS fishing trace onto a crossbar near=20 the mass to ensure that the mass + arm do not rotate about it's axis.=20 Otherwise you need to have the top wire support a few inches above the arm=20= and the=20 damping plate level with the C of G of the mass. If you don't do this, the=20= arm=20 will oscillate in rotation when a quake comes along. This motion is NOT=20 damped and it can give you a false output signal as the coil rocks in the m= agnet=20 field. Check the background trace with a FFT for any peaks of a few Hz. Lehmans are extremely sensitive to air current movements / drafts. You=20 need a thermally insulated box with all the joint lines airtight / sealed.=20= You=20 can buy clear mylar film for photocopying transparancies. Use this to make=20 two layer windows with an air gap in between. The mounting bolts and nuts need to be of the same metal. I use a wavy=20 washer + an extra nut on top of the baseplate to ensure that the three=20 levelling screws are always held in tension and do not move as the temperat= ure=20 changes.=20 =20 Regards, =20 Chris Chapman =20 =20
In a message dated 07/06/2008, gel@................. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>

I=E2=80=99m the process of adjusting the resonant per= iod of my=20 first Lehman seismometer. Are there other parameters besides the angle tha= t I=20 should be aware in achieving a long period. How about the position of the=20 mass, should I move the mass towards the end of the pendulum. This assumes= I=20 have a good mounting method for the support wire and a low friction=20 bearing.

Hi Gary,
 
    You can use C of G mass to pivot lengths betwee= n=20 about 1and 3 ft. The longer lengths are easier to set up and to adjust. With= =20 short lengths you are very sensitive to ground tilt variations. The=20 increase in period with length is low above 3 ft and the arm becomes difficu= lt=20 to make rigid and the temperature + air movements (noise) more difficult to=20 control / reduce. If you wanted a vertical pendulum with a 4 second period,=20= you=20 would need a 12 ft long arm...
    I use a V support wire made from SS fishing tra= ce=20 onto a crossbar near the mass to ensure that the mass + arm do not rotate ab= out=20 it's axis. Otherwise you need to have the top wire support a few inches abov= e=20 the arm and the damping plate level with the C of G of the mass. If you= =20 don't do this, the arm will oscillate in rotation when a quake comes along.=20= This=20 motion is NOT damped and it can give you a false output signal as the coil r= ocks=20 in the magnet field. Check the background trace with a FFT for any peaks of=20= a=20 few Hz.
    Lehmans are extremely sensitive to air current=20 movements / drafts. You need a thermally insulated box with all the joint li= nes=20 airtight / sealed. You can buy clear mylar film for photocopying transparanc= ies.=20 Use this to make two layer windows with an air gap in between.
    The mounting bolts and nuts need to be of the s= ame=20 metal. I use a wavy washer + an extra nut on top of the baseplate to ensure=20= that=20 the three levelling screws are always held in tension and do not move a= s=20 the temperature changes.
 
    Regards,
 
    Chris Chapman
    
Subject: Pivot balls From: David Sarraf david.sarraf@............ Date: Sat, 07 Jun 2008 21:37:08 -0400 McMaster-carr sells tungsten carbide balls ranging from 1/32" dia. to 1" dia. The 1/8" diameter balls cost $10.32 for a pack of five. Swiss Jewel company (Philadelphia, PA http://www.swissjewel.com/). sells all sorts of forms in glass, ruby, and alumina. It has been many years since I used them so I can't give current prices. They do sell to industrial customers, and it may work best as a group purchase. Dave Sarraf __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Pivot balls From: JAMES RIDOUT jamesridout@.............. Date: Sun, 8 Jun 2008 09:30:14 +0100 (BST) The followin link is a picture of the top mount on my newly constructed mini lehman, it is a 5/16" dia st/st ball bearing against a (used) tungsten carbide lathe tool insert. The ball sits in a steel washer soldered to two wire crimp connectors, with carbon fibre support wires for the boom. The bottom mount (at the end of the boom) is the same arrangement, and seems to work very well!. James http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=7080079
The followin link is a picture of the top mount on my newly constructed mini lehman, it is a 5/16" dia st/st ball bearing against a (used) tungsten carbide lathe tool insert. The ball sits in a steel washer soldered to two wire crimp connectors, with carbon fibre support wires for the boom. The bottom mount (at the end of the boom) is the same arrangement, and seems to work very well!.
           James
 
Subject: Re: Pivot balls From: ChrisAtUpw@....... Date: Sun, 8 Jun 2008 05:53:56 EDT In a message dated 08/06/2008, jamesridout@.............. writes: The followin link is a picture of the top mount on my newly constructed mini lehman, it is a 5/16" dia st/st ball bearing against a (used) tungsten carbide lathe tool insert. The ball sits in a steel washer soldered to two wire crimp connectors, with carbon fibre support wires for the boom. The bottom mount (at the end of the boom) is the same arrangement, and seems to work very well!. James _http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=7080079_ (http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=7080079) Hi James, Very nice! If you ever need remake the bearing, I suggest that you put the ball on the frame and the counterplate on the arm! If you do it this way, the axis of rotation stays constant through the centre-line of the balls and this is determined by the frame settings, so you can easily dismount the arm make any alterations etc, remount it and it will still be ~ in balance. This just makes the operational setup just a bit easier. Also, if you do get a large quake and the bearing moves slightly, it will stay in adjustment. With your arrangement, you will need to set up the cross balance ~ from scratch each time you replace the ball on the flat. For the mounting the support wires, I use nylon coated SS fishing trace ~30 to 60 lbs. I make loops at the ends and use the crimp tubes supplied to clamp the loops. This seems to work very well. I hope that it all works well! Regards, Chris Chapman
In a message dated 08/06/2008, jamesridout@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
The followin link is a picture of the top mount on my newly construct= ed=20 mini lehman, it is a 5/16" dia st/st ball bearing against a (used) tungste= n=20 carbide lathe tool insert. The ball sits in a steel washer soldered to two= =20 wire crimp connectors, with carbon fibre support wires for the boom. The=20 bottom mount (at the end of the boom) is the same arrangement, and seems t= o=20 work very well!.
           James
 
http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=3D70800= 79
Hi James,
 
    Very nice!
    If you ever need remake the bearing, I suggest=20= that=20 you put the ball on the frame and the counterplate on the arm!
    If you do it this way, the axis of rotation sta= ys=20 constant through the centre-line of the balls and this is determined by the=20 frame settings, so you can easily dismount the arm make any alterations etc,= =20 remount it and it will still be ~ in balance. This just makes=20 the operational setup just a bit easier. Also, if you do get a large qu= ake=20 and the bearing moves slightly, it will stay in adjustment.
    With your arrangement, you will need to set up=20= the=20 cross balance ~ from scratch each time you replace the ball on the=20 flat. 
    For the mounting the support wires, I use nylon= =20 coated SS fishing trace ~30 to 60 lbs. I make loops at the ends and use the=20 crimp tubes supplied to clamp the loops. This seems to work=20 very well.
    I hope that it all works well!
 
    Regards,
 
    Chris Chapman
Subject: Re: Pivot balls From: Pete Rowe ptrowe@......... Date: Sun, 8 Jun 2008 10:13:56 -0700 (PDT) Hi James I'm interested in the turbine shown in your pictures. Since it isn't seismic related, reply directly to me at: pete.rowe (AT) rowelabs.com thanks, Pete --- On Sun, 6/8/08, JAMES RIDOUT wrote: > From: JAMES RIDOUT > Subject: Pivot balls > To: PSN-L@.............. > Date: Sunday, June 8, 2008, 1:30 AM > The followin link is a picture of the top mount on my newly > constructed mini lehman, it is a 5/16" dia st/st ball > bearing against a (used) tungsten carbide lathe tool > insert. The ball sits in a steel washer soldered to two > wire crimp connectors, with carbon fibre support wires for > the boom. The bottom mount (at the end of the boom) is the > same arrangement, and seems to work very well!. > James > > > http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=7080079 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: A coil or dampening plate "drop down" assembly From: "meredith lamb" paleoartifact@......... Date: Sun, 8 Jun 2008 12:27:47 -0600 Hi all, Below is a web page reference to a possible useful coil drop down (from the boom) approach you might consider to use with your possible 4 neodymium magnets and plates setup. It could be considered "risky" for the coil but thats dependent on your visual alignment skill. The same approach can be used with any dampening plate. http://seismometer.googlepages.com/coildropdown Take care, Meredith Lamb Hi all,

Below is a web page reference to a possible useful coil drop down (from the boom) approach
you might consider to use with your possible 4 neodymium magnets and plates setup.  It could
be considered "risky" for the coil but thats dependent on your visual alignment skill.  The same approach
can be used with any dampening plate.

http://seismometer.googlepages.com/coildropdown

Take care, Meredith Lamb


Subject: My First Lehman From: "Gary Lindgren" gel@................. Date: Sun, 8 Jun 2008 18:31:43 -0700 I have some pictures for the first Lehman. At this point I=92m just = getting familiar with it and learning how to set it up. I have 2 sets of = crossbars, one set is 1/8=94 SS dowel pins and the other is 1/8=94 hardened steel = dowel pins. So far I think I like the hardened steel better. The upper = mounting uses the idea from Ted, he suggested using a =BC-20 acorn nut. This = worked perfect, I drilled a .020=94 hole in the center to receive the .017=94 = dia. music wire. A nice snug fit. Then I use a =BC=94 dia. Si3N4 ball = bearing. The ball bearing grade is 5, so it is very smooth and very hard, much harder than steel. So far I have been able to achieve just under 30 sec. = resonant period. I=92ll be using the Chapman magnet system for both the sensor = and damping. The Lehman is shown here http://gelindgren.googlepages.com/lehman_6_8_08.jpg The bearing = detail: http://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg The upper mounting: = http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg and lower mounting: http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg =20 =20 Suggestions are welcome, Gary =20 =20 =20 =20 =20 Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 =20 650-326-0655 =20 = www.blue-eagle-technologies.com cymonsplace.blogspot.com=20 =20 =20

I have some pictures for the first Lehman. At this = point I’m just getting familiar with it and learning how to set it up. I have 2 = sets of crossbars, one set is 1/8” SS dowel pins and the other is = 1/8” hardened steel dowel pins. So far I think I like the hardened steel = better. The upper mounting uses the idea from Ted, he suggested using a =BC-20 acorn = nut. This worked perfect, I drilled a .020” hole in the center to = receive the ..017” dia. music wire. A nice snug fit. Then I use a =BC” = dia. Si3N4 ball bearing. The ball bearing grade is 5, so it is very smooth and very = hard, much harder than steel. So far I have been able to achieve just under 30 = sec. resonant period. I’ll be using the Chapman magnet system = for both the sensor and damping. The Lehman is shown here http://gelin= dgren.googlepages.com/lehman_6_8_08.jpg =A0=A0=A0The bearing detail: =A0http= ://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg =A0The upper mounting: = http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg =A0and lower mounting: = http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg =A0

 

Suggestions are welcome,

Gary

 

 

 

 

 

Gary Lindgren

585 Lincoln Ave

Palo Alto CA 94301

 

650-326-0655<= /span>

 

www.blue-eagle-technologies.com

cymonsplace.blogspot.com 

 

 

Subject: Re: My First Lehman From: "meredith lamb" paleoartifact@......... Date: Sun, 8 Jun 2008 22:36:34 -0600 Hi Gary, I'am overall impressed! Many thanks for the pictures! I enlarged your photo of the pivot with the free Picasa2 from Google. Its = a interesting new (too me) method of being able to center the ball bearing over the width of the mast. With the ball bearing centered inbetween two of the four pins; you're getting two contacts on the ball bearing....which is a "crosse= d rod" pivot essentially...which is a very good low friction type of pivot; but they can wander one way or the other down their "guide channel" over time. I would think with the mass entending beyond the front leveling setscrew...the overall platform stability could be balance conpromised by stress somewhat. You would likely be forced to use the Chapman magnet system off the aluminum base plate.....or.......pull the mass in; shorten the upper pivot wire attachment, install the magnet assemblys; and likely settle for a lesser long period. Then again....one might add on (or replace the base) out with more aluminum, and the leveling setscrew further out also. Take care, Meredith Lamb On Sun, Jun 8, 2008 at 7:31 PM, Gary Lindgren wrote= : > I have some pictures for the first Lehman. At this point I'm just gettin= g > familiar with it and learning how to set it up. I have 2 sets of crossbar= s, > one set is 1/8" SS dowel pins and the other is 1/8" hardened steel dowel > pins. So far I think I like the hardened steel better. The upper mounting > uses the idea from Ted, he suggested using a =BC-20 acorn nut. This worke= d > perfect, I drilled a .020" hole in the center to receive the .017" dia. > music wire. A nice snug fit. Then I use a =BC" dia. Si3N4 ball bearing. T= he > ball bearing grade is 5, so it is very smooth and very hard, much harder > than steel. So far I have been able to achieve just under 30 sec. resonan= t > period. I'll be using the *Chapman* magnet system for both the sensor and > damping. The Lehman is shown here > http://gelindgren.googlepages.com/lehman_6_8_08.jpg The bearing detail= : > http://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg The upper > mounting: http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg= and lower mounting: > http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg > > > > Suggestions are welcome, > > Gary > > > > > > > > > > > > *Gary Lindgren*** > > *585 Lincoln Ave*** > > *Palo Alto CA 94301*** > > > > 650-326-0655 > > > > www.blue-eagle-technologies.com > > cymonsplace.blogspot.com > > > > > Hi Gary,

I'am overall impressed!  Many thanks for the pictu= res!

I enlarged your photo of the pivot with the free Picasa2 from G= oogle.  Its a interesting new (too me) method of being able
to cent= er the ball bearing over the width of the mast.  With the ball bearing= centered inbetween two of the four
pins; you're getting two contacts on the ball bearing....which is a &qu= ot;crossed rod" pivot essentially...which is a very good
low fricti= on type of pivot; but they can wander one way or the other down their "= ;guide channel" over time. 

I would think with the mass entending beyond the front leveling setscre= w...the overall platform stability could be balance
conpromised by stres= s somewhat.   You would likely be forced to use the Chapman magnet sys= tem off the aluminum base
plate.....or.......pull the mass in; shorten the upper pivot wire attachmen= t, install the magnet assemblys; and likely settle
for a lesser long per= iod.  Then again....one might add on (or replace the base) out with mo= re aluminum, and the leveling
setscrew further out also.

Take care, Meredith Lamb

On Sun, Jun 8, 2008 at 7:31 PM, Gary Lindgren <gel@.................> wrote:
<= blockquote class=3D"gmail_quote" style=3D"border-left: 1px solid rgb(204, 2= 04, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">

I have some pictures for the first Lehman. At this point I'm just getting familiar with it and learning how to set it up. I have 2 sets = of crossbars, one set is 1/8" SS dowel pins and the other is 1/8" hardened steel dowel pins. So far I think I like the hardened steel better.= The upper mounting uses the idea from Ted, he suggested using a =BC-20 acorn nu= t. This worked perfect, I drilled a .020" hole in the center to receive the ..017" dia. music wire. A nice snug fit. Then I use a =BC" dia. Si3N4 ball bearing. The ball bearing grade is 5, so it is very smooth and very ha= rd, much harder than steel. So far I have been able to achieve just under 30 se= c. resonant period. I'll be using the Chapman magnet system for both the sensor and damping. The Lehman is shown here http://gelindgren.g= ooglepages.com/lehman_6_8_08.jpg    The bearing detail:  http://gelindgre= n.googlepages.com/lehman_bearing_6_8_08.jpg  The upper mounting: http://gelindgren.googlepages.= com/lehman_upper_mount_6_8_08.jpg  and lower mounting: http://gelindgren.googlepages.= com/lehman_lower_mount_6_8_08.jpg  

 

Suggestions are welcome,

Gary

 

 

 

 

 

Gary Lindg= ren

585 Lincol= n Ave

Palo Alto = CA 94301

 

650-326-0655

 

www.blue-eagle-t= echnologies.com

cymonsplace.blogspo= t.com 

 

 


Subject: Re: My First Lehman From: ChrisAtUpw@....... Date: Mon, 9 Jun 2008 07:26:59 EDT In a message dated 2008/06/09, gel@................. writes: > I have some pictures for the first Lehman. At this point I=E2=80=99m just=20= getting=20 > familiar with it and learning how to set it up. I have 2 sets of crossbars= ,=20 > one set is 1/8=E2=80=9D SS dowel pins and the other is 1/8=E2=80=9D harden= ed steel dowel pins.=20 >=20 Hi Gary, Ordinary steel will corrode in the damp air during rolling contact.=20 They are OK for trying out, but they won't last long. Are the SS dowel pins=20 hardened, ground and polished? Can you get them in something like type 415=20 martensitic SS? Incidentally, you can buy martesitic SS rod quite easily, bu= t you=20 would have to harden it. So far I think I like the hardened steel better. The upper mounting uses the= =20 idea=20 > from Ted, he suggested using a =C2=BC-20 acorn nut. This worked perfect, I= =20 > drilled a .020=E2=80=9D hole in the center to receive the .017=E2=80=9D di= a. music wire. A nice=20 > snug fit.=20 If this works, fine! I use thinner nickel plated music wire, 8 to 12=20 thou OD. I fit an L bracket at the top of the column with a horizontal hole=20= in=20 it. I fit a bolt with a hole bored through the centre and clamp the wire=20 between flat washers. This seems to work OK. Then I use a =C2=BC=E2=80=9D dia. Si3N4 ball bearing. The ball bearin= g grade is 5,=20 so it is very=20 > smooth and very hard, much harder than steel. So far I have been able to=20 > achieve just under 30 sec.resonant period. I=E2=80=99ll be using the Chapm= an magnet=20 > system for both the sensor and damping. The Lehman is shown here=20 > http://gelindgren.googlepages.com/lehman_6_8_08.jpg The bearing detail:= =20 > http://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg The upper mou= nting:=20 > http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg and lower= mounting:=20 > http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg =20 If you are getting 30 seconds, that is great.=20 Regards, Chris Chapman =20 In a me= ssage dated 2008/06/09, gel@................. writes:

I have some pictures for the fi= rst Lehman. At this point I=E2=80=99m just getting familiar with it and lear= ning how to set it up. I have 2 sets of crossbars, one set is 1/8=E2=80=9D S= S dowel pins and the other is 1/8=E2=80=9D hardened steel dowel pins.

Hi Gary,

       Ordinary steel will corrode in the damp= air during rolling contact. They are OK for trying out, but they won't last= long. Are the SS dowel pins hardened, ground and polished? Can you get them= in something like type 415 martensitic SS? Incidentally, you can buy martes= itic SS rod quite easily, but you would have to harden it.

So far I think I like the hardened steel better. The upper mounting uses the= idea

from Ted, he suggested using a= =C2=BC-20 acorn nut. This worked perfect, I drilled a .020=E2=80=9D hole in= the center to receive the .017=E2=80=9D dia. music wire. A nice snug fit. <= /FONT>=


       If this works, fine! I use thinner nic= kel plated music wire, 8 to 12 thou OD. I fit an L bracket at the top of the= column with a horizontal hole in it. I fit a bolt with a hole bored through= the centre and clamp the wire between flat washers. This seems to work OK.<= BR>
       Then I use a =C2=BC=E2=80=9D dia. Si3N4= ball bearing. The ball bearing grade is 5, so it is very

smooth and very hard, much har= der than steel. So far I have been able to achieve just under 30 sec.resonan= t period. I=E2=80=99ll be using the Chapman magnet system for both th= e sensor and damping. The Lehman is shown here http://gelindgren.googlepages.com/lehman_= 6_8_08.jpg    The bearing detail:  http://gelindgren.goo= glepages.com/lehman_bearing_6_8_08.jpg  The upper mounting: http://= gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg  and lower= mounting: http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg 


       If you are getting 30 seconds, that is=20= great.

       Regards,

       Chris Chapman
Subject: Re: My First Lehman From: tchannel1@............ Date: Mon, 9 Jun 2008 06:25:03 -0600 Gary, These look great.........I am sure this sensor is well under = way.........To you have you coil yet? Ted ----- Original Message -----=20 From: Gary Lindgren=20 To: PSN List=20 Sent: Sunday, June 08, 2008 7:31 PM Subject: My First Lehman I have some pictures for the first Lehman. At this point I'm just = getting familiar with it and learning how to set it up. I have 2 sets of = crossbars, one set is 1/8" SS dowel pins and the other is 1/8" hardened = steel dowel pins. So far I think I like the hardened steel better. The = upper mounting uses the idea from Ted, he suggested using a =BC-20 acorn = nut. This worked perfect, I drilled a .020" hole in the center to = receive the .017" dia. music wire. A nice snug fit. Then I use a =BC" = dia. Si3N4 ball bearing. The ball bearing grade is 5, so it is very = smooth and very hard, much harder than steel. So far I have been able to = achieve just under 30 sec. resonant period. I'll be using the Chapman = magnet system for both the sensor and damping. The Lehman is shown here = http://gelindgren.googlepages.com/lehman_6_8_08.jpg The bearing = detail: http://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg = The upper mounting: = http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg and = lower mounting: = http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg =20 =20 Suggestions are welcome, Gary =20 =20 =20 =20 =20 Gary Lindgren 585 Lincoln Ave Palo Alto CA 94301 =20 650-326-0655 =20 www.blue-eagle-technologies.com cymonsplace.blogspot.com=20 =20 =20
Gary, These look great.........I am = sure this=20 sensor is well under way.........To you have you coil yet?
Ted
----- Original Message -----
From:=20
Gary=20 Lindgren
Sent: Sunday, June 08, 2008 = 7:31 PM
Subject: My First Lehman

I have some pictures for the first Lehman. At = this point=20 I=92m just getting familiar with it and learning how to set it up. I = have 2 sets=20 of crossbars, one set is 1/8=94 SS dowel pins and the other is 1/8=94 = hardened=20 steel dowel pins. So far I think I like the hardened steel better. The = upper=20 mounting uses the idea from Ted, he suggested using a =BC-20 acorn = nut. This=20 worked perfect, I drilled a .020=94 hole in the center to receive the = ..017=94 dia.=20 music wire. A nice snug fit. Then I use a =BC=94 dia. Si3N4 ball = bearing. The ball=20 bearing grade is 5, so it is very smooth and very hard, much harder = than=20 steel. So far I have been able to achieve just under 30 sec. resonant = period.=20 I=92ll be using the Chapman magnet system for both the sensor = and=20 damping. The Lehman is shown here http://gelin= dgren.googlepages.com/lehman_6_8_08.jpg=20    The bearing detail:  http= ://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg=20  The upper mounting: = http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg=20  and lower mounting: = http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg=20  

 

Suggestions are welcome,

Gary

 

 

 

 

 

Gary=20 Lindgren

585=20 Lincoln Ave

Palo=20 Alto CA 94301

 

650-326-0655

 

www.blue-eagle-technologies.com

cymonsplace.blogspot.com 

 

 

Subject: RE: My First Lehman From: "Gary Lindgren" gel@................. Date: Mon, 9 Jun 2008 17:24:30 -0700 H Chris, I don=E2=80=99t think we need to worry too much about the steel = corroding here in California. The air is very dry even in the basement = where the seismometer will be located. I purchased the SS pins from = Small Parts. They seem pretty smooth, but by my finger nail test says = they are not as hard as the steel dowel pins. Now 415 matensitic SS, I = have not come across this one. I=E2=80=99ll have to look into that. = Could that be an EU term? The .017 music wire is nickel plated. Thank you for the comments, they are most useful. Gary =20 From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of ChrisAtUpw@....... Sent: Monday, June 09, 2008 4:27 AM To: psn-l@.............. Subject: Re: My First Lehman =20 In a message dated 2008/06/09, gel@................. writes: I have some pictures for the first Lehman. At this point I=E2=80=99m = just getting familiar with it and learning how to set it up. I have 2 = sets of crossbars, one set is 1/8=E2=80=9D SS dowel pins and the other = is 1/8=E2=80=9D hardened steel dowel pins.=20 Hi Gary, Ordinary steel will corrode in the damp air during rolling = contact. They are OK for trying out, but they won't last long. Are the = SS dowel pins hardened, ground and polished? Can you get them in = something like type 415 martensitic SS? Incidentally, you can buy = martesitic SS rod quite easily, but you would have to harden it. So far I think I like the hardened steel better. The upper mounting uses = the idea=20 from Ted, he suggested using a =C2=BC-20 acorn nut. This worked perfect, = I drilled a .020=E2=80=9D hole in the center to receive the = ..017=E2=80=9D dia. music wire. A nice snug fit.=20 If this works, fine! I use thinner nickel plated music wire, 8 to = 12 thou OD. I fit an L bracket at the top of the column with a = horizontal hole in it. I fit a bolt with a hole bored through the centre = and clamp the wire between flat washers. This seems to work OK. Then I use a =C2=BC=E2=80=9D dia. Si3N4 ball bearing. The ball = bearing grade is 5, so it is very=20 smooth and very hard, much harder than steel. So far I have been able to = achieve just under 30 sec.resonant period. I=E2=80=99ll be using the = Chapman magnet system for both the sensor and damping. The Lehman is = shown here http://gelindgren.googlepages.com/lehman_6_8_08.jpg The = bearing detail: = http://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg The upper = mounting: = http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg and = lower mounting: = http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg =20 If you are getting 30 seconds, that is great.=20 Regards, Chris Chapman=20

H Chris,

I don=E2=80=99t think we need to worry too much about the = steel corroding here in California. The air is very dry even in the basement = where the seismometer will be located. I purchased the SS pins from Small = Parts. They seem pretty smooth, but by my finger nail test says they are not as hard = as the steel dowel pins. Now 415 matensitic SS, I have not come across this = one. I=E2=80=99ll have to look into that. Could that be an EU term? The .017 music wire is = nickel plated.

Thank you for the comments, they are most = useful.

Gary

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of ChrisAtUpw@.......
Sent: Monday, June 09, 2008 4:27 AM
To: psn-l@..............
Subject: Re: My First Lehman

 

In a message dated 2008/06/09, gel@................. writes:


I have some pictures for the first Lehman. At this point I=E2=80=99m just = getting familiar with it and learning how to set it up. I have 2 sets of = crossbars, one set is 1/8=E2=80=9D SS dowel pins and the other is 1/8=E2=80=9D hardened = steel dowel pins.



Hi Gary,

       Ordinary steel will corrode in the = damp air during rolling contact. They are OK for trying out, but they won't = last long. Are the SS dowel pins hardened, ground and polished? Can you get = them in something like type 415 martensitic SS? Incidentally, you can buy = martesitic SS rod quite easily, but you would have to harden it.

So far I think I like the hardened steel better. The upper mounting uses = the idea

from Ted, he suggested using a =C2=BC-20 = acorn nut. This worked perfect, I drilled a .020=E2=80=9D hole in the center to = receive the .017=E2=80=9D dia. music wire. A nice snug fit.



       If this works, fine! I use thinner = nickel plated music wire, 8 to 12 thou OD. I fit an L bracket at the top of the = column with a horizontal hole in it. I fit a bolt with a hole bored through the = centre and clamp the wire between flat washers. This seems to work OK.

       Then I use a =C2=BC=E2=80=9D dia. = Si3N4 ball bearing. The ball bearing grade is 5, so it is very

smooth and very hard, much harder than = steel. So far I have been able to achieve just under 30 sec.resonant period. = I=E2=80=99ll be using the Chapman magnet system for both the sensor and damping. = The Lehman is shown here http://gelin= dgren.googlepages.com/lehman_6_8_08.jpg    The bearing detail:  http= ://gelindgren.googlepages.com/lehman_bearing_6_8_08.jpg  The upper mounting: = http://gelindgren.googlepages.com/lehman_upper_mount_6_8_08.jpg = and lower mounting: = http://gelindgren.googlepages.com/lehman_lower_mount_6_8_08.jpg =



       If you are getting 30 seconds, that = is great.

       Regards,

       Chris Chapman

Subject: Tungsten Pins From: JAMES RIDOUT jamesridout@.............. Date: Tue, 10 Jun 2008 06:40:51 +0100 (BST) Hi All, If anyones Interested, I can get a good supply of 3mm & 6mm Broken milling cutter shanks. They are about 40mm long ,and made of Tungnsten Carbide. James
Hi All,
           If anyones  Interested, I can get a good supply of 3mm & 6mm Broken milling cutter shanks. They are about 40mm long ,and made of Tungnsten Carbide.
                                                  James
Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Tue, 10 Jun 2008 09:19:55 EDT In a message dated 2008/06/10, jamesridout@.............. writes: > If anyones Interested, I can get a good supply of 3mm & 6mm Broken milling > cutter shanks. They are about 40mm long ,and made of Tungnsten Carbide. Hi James, That could be very helpful. They could both be used in seisometers. Do the cutters hve a screw thread on one end and the cutter on the other, or do they use a smooth shank, please? Regards, Chris Chapman In a me= ssage dated 2008/06/10, jamesridout@.............. writes:

If anyones  Interested, I=20= can get a good supply of 3mm & 6mm Broken milling cutter shanks. They ar= e about 40mm long ,and made of Tungnsten Carbide.


Hi James,

       That could be very helpful. They could=20= both be used in seisometers.

       Do the cutters hve a screw thread on on= e end and the cutter on the other, or do they use a smooth shank, please?
       Regards,

       Chris Chapman
Subject: Re: Tungsten Pins From: tchannel1@............ Date: Tue, 10 Jun 2008 07:36:43 -0600 Hi James, I too would be very interested in getting some of these. = Please, when you have time email me with details. Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Tuesday, June 10, 2008 7:19 AM Subject: Re: Tungsten Pins In a message dated 2008/06/10, jamesridout@.............. writes: If anyones Interested, I can get a good supply of 3mm & 6mm Broken = milling cutter shanks. They are about 40mm long ,and made of Tungnsten = Carbide. Hi James, That could be very helpful. They could both be used in = seisometers.=20 Do the cutters hve a screw thread on one end and the cutter on = the other, or do they use a smooth shank, please? Regards, Chris Chapman
Hi James, I too would be very = interested in getting=20 some of these.  Please, when you have time email me with=20 details.
 
 
Ted
----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Tuesday, June 10, 2008 = 7:19=20 AM
Subject: Re: Tungsten = Pins

In a=20 message dated 2008/06/10, jamesridout@..............= =20 writes:

If anyones  Interested, I can get a good supply of = 3mm=20 & 6mm Broken milling cutter shanks. They are about 40mm long = ,and made=20 of Tungnsten Carbide.

Hi=20 James,

       That could be very = helpful.=20 They could both be used in seisometers.=20

       Do the cutters hve a = screw thread=20 on one end and the cutter on the other, or do they use a smooth shank, = please?

      =20 Regards,

       Chris = Chapman
=20
Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Tue, 10 Jun 2008 11:19:34 -0600 Chris is right to emphasize using carbide...or any of the harder and/or smoother surface materials...they are all better for seismo pivot material than run of the mill steel and iron rods. The pivot itself is the "heart" of your seismo enertia mass response working reasonably well or (too often) poorly....you HAVE TOO eliminate as much friction as possible....or, in the end be very disappointed and perhaps wondering why your masterpiece doesn't respond as well as others do. Ebay has carbide rods/blanks and of course one could probably purchase such from a variety of other web sellers. These are simply rounded rods/blanks that some machine shops use to diamond wheel grind one end into a cutting edge they want. Use search and enter "carbide rod"; for viewing. "machprodinc" specifically has a size that would probably be VERY convenient to initially use, its 1/8" diameter X 1.5" length, and the outside diameter surface appears to be quite finely ground...but there is none anywhere I know of that are ground and diamond POLISHED. The auction is for 50 of them and starts at $19.50. Its a "C4" grade which is 8% cobalt and 92% tungsten carbide. Theres ALWAYS something better around of course; but it very easily beats using any common steel rod/s for its hardness (avoiding surface indentations), smoother ground surface use consistency and simply its use longevity. The seller started with a box of 1000 of them recently and will likely have these auctions for quite some time to come. One could obviously likely buy the same or better elsewhere for the exact number of rods they actually want. Be aware that sellers falsely claiming their carbide is polished...it likely isn't...they don't know the difference between having something ground (a vague silver gray shiny appearance) and something diamond grit ~ polished (a more mirror like reflection). Also most carbide isn't even ground, its shape molded....it usually looks blackish, but can be other colors....you sure don't want that rough a surface. Grinding is simply a grit size scratching action...and finer diamond based grits (polishing) yield a much smoother and visually they can yield a ~ mirror reflection finish. If....you want to go further and actually do ~ polishing, I note that Titan Tool Supply, Inc. has a variety of diamond grits on small size foil and sheets. http://www.titantoolsupply.com/catalog.asp?prodid=506100 This diamond grit material will likely cost alot more than the carbide rod/s. Theres probably many others around with cheaper or better material. Take care, Meredith Chris is right to emphasize using carbide...or any of the harder and/or smoother surface materials...they are all better for seismo pivot
material than run of the mill steel and iron rods.  The pivot itself is the "heart" of your seismo enertia mass response working
reasonably well or (too often) poorly....you HAVE TOO eliminate as much friction as possible....or, in the end be very disappointed
and perhaps wondering why your masterpiece doesn't respond as well as others do. 

Ebay has carbide rods/blanks and of course one could probably purchase such from a variety of other web sellers.
These are simply rounded rods/blanks that some machine shops use to diamond wheel grind one end into a cutting edge they want.

Use search and enter "carbide rod"; for viewing.   "machprodinc" specifically has a size that would probably be
VERY convenient to initially use, its 1/8" diameter X 1.5" length, and the outside diameter surface appears to be quite finely ground...but
there is none anywhere I know of that are ground and diamond POLISHED.  The auction is for 50 of them and starts at $19.50.
Its a "C4" grade which is 8% cobalt and 92% tungsten carbide.  Theres ALWAYS something better around of course;
but it very easily beats using any common steel rod/s for its hardness (avoiding surface indentations), smoother ground surface use
consistency and simply its use longevity.  The seller started with a box of 1000 of them recently and will likely have these auctions
for quite some time to come.

One could obviously likely buy the same or better elsewhere for the exact number of rods they actually want.

Be aware that sellers falsely claiming their carbide is polished...it likely isn't...they don't know the difference between
having something ground (a vague silver gray shiny appearance) and something diamond grit ~ polished (a more mirror like reflection).
Also most carbide isn't even ground, its shape molded....it usually looks blackish, but can be other colors....you sure don't want
that rough a surface.  Grinding is simply a grit size scratching action...and finer diamond based grits (polishing) yield a much smoother
and visually they can yield a ~ mirror reflection finish.

If....you want to go further and actually do ~ polishing, I note that Titan Tool Supply, Inc. has a variety of diamond
grits on small size foil and sheets.  http://www.titantoolsupply.com/catalog.asp?prodid=506100
This diamond grit material will likely cost alot more than the carbide rod/s.  Theres probably many others around with cheaper
or better material.

Take care, Meredith


Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Tue, 10 Jun 2008 15:27:25 EDT In a message dated 2008/06/10, paleoartifact@......... writes: > If you want to go further and actually do ~ polishing, I note that Titan > Tool Supply, Inc. has a variety of diamond grits on small size foil and sheets. > http://www.titantoolsupply.com/catalog.asp?prodid=506100 > This diamond grit material will likely cost alot more than the carbide > rod/s. Theres probably many others around with cheaper or better material. Hi Meredith, Strangely enough diamond paste is not very expensive. I pay $10 for a syringe. You use a medium grade, not a fine grade. Titan products seem to be overpriced. You can use a copper tube to polish a Tungsten Carbide rod, OK. This takes quite a while by hand, but using a slow drill to hold the rod is quite practicable. Alternatively, wrap a strip of Cu sheet in a U around a suitable drill shank. Regards, Chris In a me= ssage dated 2008/06/10, paleoartifact@......... writes:

If you want to go further and a= ctually do ~ polishing, I note that Titan Tool Supply, Inc. has a variety of= diamond grits on small size foil and sheets.  http://www.titantoolsupply.co= m/catalog.asp?prodid=3D506100
This diamond grit material will likely cost alot more than the carbide rod/s= ..  Theres probably many others around with cheaper or better material.<= /BLOCKQUOTE>

Hi Meredith,

       Strangely enough diamond paste is not v= ery expensive. I pay $10 for a syringe. You use a medium grade, not a fine g= rade. Titan products seem to be overpriced.
       You can use a copper tube to polish a T= ungsten Carbide rod, OK. This takes quite a while by hand, but using a slow=20= drill to hold the rod is quite practicable. Alternatively, wrap a strip of C= u sheet in a U around a suitable drill shank.

       Regards,

       Chris
Subject: winquake and seismograms From: "Thomas Dick" dickthomas01@............. Date: Tue, 10 Jun 2008 15:55:49 -0500 Is there any way to download earthquake files from (let's say) Wilber and manipulate them with Winquake? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: winquake and seismograms From: Bob Hancock carpediem1@......... Date: Tue, 10 Jun 2008 14:32:42 -0700 Its quite easy. When you download the files make sure you request them in SAC Binary format. If you plan on making datasets, you will need the actual receiver sensitivity along with latitude and longitude of the station. SAC files do not come in all the same length. They are off by a few seconds. You will first need to crop the files through WinQuake. I usually request 5 minutes of data before the P wave and whatever I need after. After cropping the files to the same length and starting time, I then add the sensor data, followed by the event data. I then save the data in PSN4 format, after which you can load the three files into a dataset and analyze it as necessary through WinQuake. If you are working with a nearby station, this is a good way to check your sensitivity. Good Luck Bob Hancock On 6/10/08 1:55 PM, "Thomas Dick" wrote: > Is there any way to download earthquake files from (let's say) Wilber and > manipulate them with Winquake? > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Tue, 10 Jun 2008 15:55:00 -0600 Hi Chris, Your techniques is a total unknown to me. How do you do your method/s? I can use my imagination but...it could be quite wrong of course. It "sounds" like a horizontal tumbler action of sorts. I presume; the copper rod (one closed end) is rotated by the outside chuck slow drill , with the carbide and diamond paste tumble therein? I presume the "U" copper is stationary and the slow steel (?) drill rod simply rotates the carbide rod laid atop it; while the diamond paste "slurry" works? Why just the medium grit? What is the medium grit? Would a drill press holding a portion of the carbide and a suitable cloth/pad with the diamond paste thereon work abit faster for the "selective" portion of the carbide rod used? It seems like it is kind of a "art". Take care, Meredith On Tue, Jun 10, 2008 at 1:27 PM, wrote: > In a message dated 2008/06/10, paleoartifact@......... writes: > > If you want to go further and actually do ~ polishing, I note that Titan > Tool Supply, Inc. has a variety of diamond grits on small size foil and > sheets. http://www.titantoolsupply.com/catalog.asp?prodid=506100 > This diamond grit material will likely cost alot more than the carbide > rod/s. Theres probably many others around with cheaper or better material. > > > > Hi Meredith, > > Strangely enough diamond paste is not very expensive. I pay $10 for > a syringe. You use a medium grade, not a fine grade. Titan products seem to > be overpriced. > You can use a copper tube to polish a Tungsten Carbide rod, OK. This > takes quite a while by hand, but using a slow drill to hold the rod is quite > practicable. Alternatively, wrap a strip of Cu sheet in a U around a > suitable drill shank. > > Regards, > > Chris Hi Chris,

Your techniques is a total unknown to me.  How do you do your method/s?  I can use my
imagination but...it could be quite wrong of course.  It "sounds" like a horizontal tumbler
action of sorts. 

I presume; the copper rod (one closed end) is rotated by the outside chuck slow drill , with the carbide and diamond paste
tumble therein?

I presume the "U" copper is stationary and the slow steel (?) drill rod simply rotates the carbide rod laid
atop it; while the diamond paste "slurry" works?

Why just the medium grit?  What is the medium grit?

Would a drill press holding a portion of the carbide and a suitable cloth/pad with the diamond paste thereon work abit faster
for the "selective" portion of the carbide rod used?

It seems like it is kind of a "art".

Take care, Meredith

On Tue, Jun 10, 2008 at 1:27 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/06/10, paleoartifact@......... writes:

If you want to go further and actually do ~ polishing, I note that Titan Tool Supply, Inc. has a variety of diamond grits on small size foil and sheets.  http://www.titantoolsupply.com/catalog.asp?prodid=506100
This diamond grit material will likely cost alot more than the carbide rod/s.  Theres probably many others around with cheaper or better material.


Hi Meredith,

       Strangely enough diamond paste is not very expensive. I pay $10 for a syringe. You use a medium grade, not a fine grade. Titan products seem to be overpriced.
       You can use a copper tube to polish a Tungsten Carbide rod, OK. This takes quite a while by hand, but using a slow drill to hold the rod is quite practicable. Alternatively, wrap a strip of Cu sheet in a U around a suitable drill shank.

       Regards,

       Chris

Subject: Re: Tungsten Pins From: "Dale Hardy" photon1@........... Date: Wed, 11 Jun 2008 09:10:20 +1000
 
<there is none anywhere I know of that are ground and diamond=20 POLISHED.  The auction is for 50 of them <
I use the shafts salvaged from capstan motors from VCR machines, = they=20 are Tungsten carbide approx 50mm long and 3mm diameter and = Very=20 highly polished ( mirror finish )
Check your local electronics repairer ( if they exist in your = area :)=20 dying breed nowdays)
Dale
Subject: RE: Tungsten Pins From: "Gary Lindgren" gel@................. Date: Tue, 10 Jun 2008 16:20:52 -0700 Meredith, This morning I ordered some round carbide blanks from http://www.centennialcarbide.com/ I don't know exactly what these will be like when I get them. But what can be done round items is to 'center-less grind' them. Machine shops can do this, so depending on what the surface finish is, this is a possibility. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Tuesday, June 10, 2008 2:55 PM To: psn-l@.............. Subject: Re: Tungsten Pins Hi Chris, Your techniques is a total unknown to me. How do you do your method/s? I can use my imagination but...it could be quite wrong of course. It "sounds" like a horizontal tumbler action of sorts. I presume; the copper rod (one closed end) is rotated by the outside chuck slow drill , with the carbide and diamond paste tumble therein? I presume the "U" copper is stationary and the slow steel (?) drill rod simply rotates the carbide rod laid atop it; while the diamond paste "slurry" works? Why just the medium grit? What is the medium grit? Would a drill press holding a portion of the carbide and a suitable cloth/pad with the diamond paste thereon work abit faster for the "selective" portion of the carbide rod used? It seems like it is kind of a "art". Take care, Meredith On Tue, Jun 10, 2008 at 1:27 PM, wrote: In a message dated 2008/06/10, paleoartifact@......... writes: If you want to go further and actually do ~ polishing, I note that Titan Tool Supply, Inc. has a variety of diamond grits on small size foil and sheets. http://www.titantoolsupply.com/catalog.asp?prodid=506100 This diamond grit material will likely cost alot more than the carbide rod/s. Theres probably many others around with cheaper or better material. Hi Meredith, Strangely enough diamond paste is not very expensive. I pay $10 for a syringe. You use a medium grade, not a fine grade. Titan products seem to be overpriced. You can use a copper tube to polish a Tungsten Carbide rod, OK. This takes quite a while by hand, but using a slow drill to hold the rod is quite practicable. Alternatively, wrap a strip of Cu sheet in a U around a suitable drill shank. Regards, Chris

Meredith,

This morning I ordered some round carbide blanks from http://www.centennialcarbide.c= om/  I don’t know exactly what these will be like when I get them. But = what can be done round items is to ‘center-less grind’ them. = Machine shops can do this, so depending on what the surface finish is, this is a = possibility.

Gary

 

 

 

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Tuesday, June 10, 2008 2:55 PM
To: psn-l@..............
Subject: Re: Tungsten Pins

 

Hi Chris,

Your techniques is a total unknown to me.  How do you do your method/s?  I can use my
imagination but...it could be quite wrong of course.  It "sounds" like a horizontal tumbler
action of sorts. 

I presume; the copper rod (one closed end) is rotated by the outside = chuck slow drill , with the carbide and diamond paste
tumble therein?

I presume the "U" copper is stationary and the slow steel (?) = drill rod simply rotates the carbide rod laid
atop it; while the diamond paste "slurry" works?

Why just the medium grit?  What is the medium grit?

Would a drill press holding a portion of the carbide and a suitable = cloth/pad with the diamond paste thereon work abit faster
for the "selective" portion of the carbide rod used?

It seems like it is kind of a "art".

Take care, Meredith

On Tue, Jun 10, 2008 at 1:27 PM, <ChrisAtUpw@.......> = wrote:

In a message dated 2008/06/10, paleoartifact@......... writes:


If you want to go further and actually do ~ polishing, I note that Titan = Tool Supply, Inc. has a variety of diamond grits on small size foil and sheets.  http://www.titantoolsupply.com/catalog.asp?prodid=3D506= 100
This diamond grit material will likely cost alot more than the carbide rod/s.  Theres probably many others around with cheaper or better material.

 

Hi Meredith,

       Strangely enough diamond paste is = not very expensive. I pay $10 for a syringe. You use a medium grade, not a fine = grade. Titan products seem to be overpriced.
       You can use a copper tube to polish = a Tungsten Carbide rod, OK. This takes quite a while by hand, but using a slow = drill to hold the rod is quite practicable. Alternatively, wrap a strip of Cu = sheet in a U around a suitable drill shank.

       Regards,

       Chris

 

Subject: Re: winquake and seismograms From: "Thomas Dick" dickthomas01@............. Date: Tue, 10 Jun 2008 18:25:17 -0500 Thanks Bob...I tried seed and miniseed but Winquake didn't like it. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Tue, 10 Jun 2008 18:15:08 -0600 Hi Gary, You're a man after my own heart economy wise....I see that the round 1/8" X 1.5" with the ultra-microfine finish is just 78 cents each!!! Amazing price and quite affordable! Of course shipping is a likely "pained" expense. I didn't look for any minimum order note; it looks like you have to order first and then find out. Neither do they say exactly what brand they are or the finer details; but a wild guess is they could be (Japan; very good quality) Mitsubishi C4's also, just like on E-Bay. Most of the time that size is used to grind down to make drills for circuit boards. They will work as-is, a heck of a lot better than plain iron/steel rods, and of course much longer. A finer "polish" at this time, is kind of a unknown procedure. I'd "run them", myself.....as is...as your "crossed rod" pivot is probably the best relatively frictionless pivot there is for a Lehman. Very well done!!! Take care, Meredith On Tue, Jun 10, 2008 at 5:20 PM, Gary Lindgren wrote: > Meredith, > > This morning I ordered some round carbide blanks from > http://www.centennialcarbide.com/ I don't know exactly what these will be > like when I get them. But what can be done round items is to 'center-less > grind' them. Machine shops can do this, so depending on what the surface > finish is, this is a possibility. > > Gary > > > > > Hi Gary,

You're a man after my own heart economy wise....I see that the round 1/8" X 1.5" with the ultra-microfine finish is just 78 cents each!!!
Amazing price and quite affordable!  Of course shipping is a likely "pained" expense.  I didn't look for any minimum order note; it looks
like you have to order first and then find out.  Neither do they say exactly what brand they are or the finer details; but a wild guess is
they could be (Japan; very good quality) Mitsubishi C4's also, just like on E-Bay.  Most of the time that size is used to grind down to
make drills for circuit boards.

They will work as-is, a heck of a lot better than plain iron/steel rods, and of course much longer.  A finer "polish" at this time, is
kind of a unknown procedure.  I'd "run them", myself.....as is...as your "crossed rod" pivot is probably the best relatively frictionless pivot there
is for a Lehman.

Very well done!!!

Take care, Meredith

On Tue, Jun 10, 2008 at 5:20 PM, Gary Lindgren <gel@.................> wrote:

Meredith,

This morning I ordered some round carbide blanks from http://www.centennialcarbide.com/  I don't know exactly what these will be like when I get them. But what can be done round items is to 'center-less grind' them. Machine shops can do this, so depending on what the surface finish is, this is a possibility.

Gary

 

 


Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Tue, 10 Jun 2008 18:30:24 -0600 Excellent Dale! Thanks so much for the salvage note! Hmmm....with summertime yard/garage sales; one might pick up some quite cheap! Of course their diameters could vary among the manufacturers, as well as the lengths too. I think I'd even go "dumpster diving" if I saw one therein; just to check out a machine.....ha. Take care, Meredith Lamb On Tue, Jun 10, 2008 at 5:10 PM, Dale Hardy wrote: > > > The auction is for 50 of them < > I use the shafts salvaged from capstan motors from VCR machines, they > are Tungsten carbide approx 50mm long and 3mm diameter and Very highly > polished ( mirror finish ) > Check your local electronics repairer ( if they exist in your area :) dying > breed nowdays) > Dale > > Excellent Dale!

Thanks so much for the salvage note!  Hmmm....with summertime yard/garage sales; one might pick up some quite cheap!
Of course their diameters could vary among the manufacturers, as well as the lengths too.  I think I'd even go "dumpster
diving" if I saw one therein; just to check out a machine.....ha.

Take care, Meredith Lamb

On Tue, Jun 10, 2008 at 5:10 PM, Dale Hardy <photon1@...........> wrote:
 
<there is none anywhere I know of that are ground and diamond POLISHED.  The auction is for 50 of them <
I use the shafts salvaged from capstan motors from VCR machines, they are Tungsten carbide approx 50mm long and 3mm diameter and Very highly polished ( mirror finish )
Check your local electronics repairer ( if they exist in your area :) dying breed nowdays)
Dale

Subject: Re: winquake and seismograms From: Bobhelenmcclure@....... Date: Tue, 10 Jun 2008 22:39:00 EDT Hi Thomas, If you use my "SAC_to_PSN.exe" program, you will get all available information, including the sensitivity, transferred to the WinQuake file format. To download this and other utilities, go to http://bobmcclure90.googlepages.com/winsac Regards, Bob ************** Vote for your city's best dining and nightlife. City's Best 2008. (http://citysbest.aol.com?ncid=aolacg00050000000102) Hi Thomas,

  If you use my "SAC_to_PSN.exe" program, you will get all available in= formation, including the sensitivity, transferred to the WinQuake file forma= t. To download this and other utilities, go to

http://bobmcclure90.googlepages.com/winsac

Regards,

Bob



**************
Vote for your city's best dining and= nightlife. City's Best 2008.
(http://citysbest.aol.com?ncid=3Daola= cg00050000000102) Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Tue, 10 Jun 2008 23:10:27 EDT In a message dated 2008/06/10, paleoartifact@......... writes: > Your techniques is a total unknown to me. How do you do your method/s? Hi Meredith, You use a copper TUBE which fits around the Tungsten Carbide rod. You put diamond paste on the rod and use the copper to polish it. The diamond chips bed into the copper surface by the pressure of the contact and they polish the hard rod. You can also make a U of copper sheet bent around a drill shank the same diameter as the rod and use diamomd paste to polish the rod. You can fit the rod in a slow drill / lathe chuck to provide the rotation. I add oil to the diamond paste to give a thick liquid. It is not difficult. Regards, Chris In a me= ssage dated 2008/06/10, paleoartifact@......... writes:

Your techniques is a total unkn= own to me.  How do you do your method/s?


Hi Meredith,

       You use a copper TUBE which fits around= the Tungsten Carbide rod. You put diamond paste on the rod and use the copp= er to polish it. The diamond chips bed into the copper surface by the pressu= re of the contact and they polish the hard rod. You can also make a U of cop= per sheet bent around a drill shank the same diameter as the rod and use dia= momd paste to polish the rod. You can fit the rod in a slow drill / lathe ch= uck to provide the rotation. I add oil to the diamond paste to give a thick=20= liquid. It is not difficult.

       Regards,

       Chris
Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Tue, 10 Jun 2008 22:17:29 -0600 Hi Chris and thanks! One more question. Can the copper tube ID be slightly larger than the carbide OD; or, is it not even that critical? Take care, Meredith Lamb On Tue, Jun 10, 2008 at 9:10 PM, wrote: > In a message dated 2008/06/10, paleoartifact@......... writes: > > Your techniques is a total unknown to me. How do you do your method/s? > > > > Hi Meredith, > > You use a copper TUBE which fits around the Tungsten Carbide rod. > You put diamond paste on the rod and use the copper to polish it. The > diamond chips bed into the copper surface by the pressure of the contact and > they polish the hard rod. You can also make a U of copper sheet bent around > a drill shank the same diameter as the rod and use diamomd paste to polish > the rod. You can fit the rod in a slow drill / lathe chuck to provide the > rotation. I add oil to the diamond paste to give a thick liquid. It is not > difficult. > > Regards, > > Chris
Hi Chris and thanks!
 
One more question.  Can the copper tube ID be slightly larger than the carbide OD; or, is it
not even that critical?
 
Take care, Meredith Lamb

On Tue, Jun 10, 2008 at 9:10 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/06/10, paleoartifact@......... writes:

Your techniques is a total unknown to me.  How do you do your method/s?


Hi Meredith,

       You use a copper TUBE which fits around the Tungsten Carbide rod. You put diamond paste on the rod and use the copper to polish it. The diamond chips bed into the copper surface by the pressure of the contact and they polish the hard rod. You can also make a U of copper sheet bent around a drill shank the same diameter as the rod and use diamomd paste to polish the rod. You can fit the rod in a slow drill / lathe chuck to provide the rotation. I add oil to the diamond paste to give a thick liquid. It is not difficult.

       Regards,

       Chris

Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Wed, 11 Jun 2008 00:56:09 EDT In a message dated 2008/06/11, paleoartifact@......... writes: > One more question. Can the copper tube ID be slightly larger than the > carbide OD; or, is it not even that critical? Hi Meredith, It is not too critical, easier if the Cu tube is not a close fit. I can buy syringes labelled Fine, Medium and Coarse. The coarse gives good results and you can then use another bit of Cu tube with the Medium to finish / polish it. Regards, Chris In a me= ssage dated 2008/06/11, paleoartifact@......... writes:

One more question.  Can th= e copper tube ID be slightly larger than the carbide OD; or, is it not even=20= that critical?


Hi Meredith,

       It is not too critical, easier if the C= u tube is not a close fit.

       I can buy syringes labelled Fine, Mediu= m and Coarse. The coarse gives good results and you can then use another bit= of Cu tube with the Medium to finish / polish  it.

       Regards,

       Chris
Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Wed, 11 Jun 2008 07:40:59 -0600 Hi Chris, Thanks Chris. Sounds like a item that should be in the seismometry "toolbox". Take care, Meredith On Tue, Jun 10, 2008 at 10:56 PM, wrote: > In a message dated 2008/06/11, paleoartifact@......... writes: > > One more question. Can the copper tube ID be slightly larger than the > carbide OD; or, is it not even that critical? > > > > Hi Meredith, > > It is not too critical, easier if the Cu tube is not a close fit. > > I can buy syringes labelled Fine, Medium and Coarse. The coarse > gives good results and you can then use another bit of Cu tube with the > Medium to finish / polish it. > > Regards, > > Chris Hi Chris,

Thanks Chris.  Sounds like a item that should be in the seismometry "toolbox".

Take care, Meredith

On Tue, Jun 10, 2008 at 10:56 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/06/11, paleoartifact@......... writes:

One more question.  Can the copper tube ID be slightly larger than the carbide OD; or, is it not even that critical?


Hi Meredith,

       It is not too critical, easier if the Cu tube is not a close fit.

       I can buy syringes labelled Fine, Medium and Coarse. The coarse gives good results and you can then use another bit of Cu tube with the Medium to finish / polish  it.

       Regards,

       Chris

Subject: Surface pivot finishes From: "meredith lamb" paleoartifact@......... Date: Wed, 11 Jun 2008 08:39:17 -0600 Hi all, The below is a reference to another of one of my unfinished "projects" web pages. It has to do with ball bearing assembly raceways which I've not yet "let go" from, and now a synthetic ruby ball as primarily a part of a untested potential pivot for a S-G, or hanging pendulum. The polished mirror surface finish reflections of the ruby ball is visible in the the last photo on the web page. Overall, the web page shows a variety of surface finishes, which is/was a topic recently on the PSN emails. The thumbnail images are capable of being enlarged acouple times with most browsers. http://seismometer.googlepages.com/ballbearingraceway Take care, Meredith Lamb Hi all,

The below is a reference to another of one of my unfinished "projects" web pages.  It has to
do with ball bearing assembly raceways which I've not yet "let go" from, and now a synthetic
ruby ball as primarily a part of a untested potential pivot for a S-G, or hanging pendulum.

The polished mirror surface finish reflections of the ruby ball is visible in the the last photo on
the web page.  Overall, the web page shows a variety of surface finishes, which is/was a
topic recently on the PSN emails.  The thumbnail images are capable of being enlarged acouple
times with most browsers.

http://seismometer.googlepages.com/ballbearingraceway

Take care, Meredith Lamb

 
Subject: Mini Lehman Damping From: JAMES RIDOUT jamesridout@.............. Date: Wed, 11 Jun 2008 18:15:24 +0100 (BST) Hi All, Does anyone have any usefull (easy) advice on setting up the damping on a Mini Lehman. I`ve read Loads of articles on this subject ,And as far as I can see The ideal amount is 0.7 - 0.8 and that means that if I walk up to the seismograph and the pen deflects 10mm ,then the pen should return 0.5mm in the opposite direction then back to zero. Is it me, or does this seem like too much. I feel i`m going to miss the more distant Quakes, on the other hand ,I dont want the machine swinging wildly after every bump. Im just after general advice. Any would be much appreciated!. Thanks In advance James
Hi All,
          Does anyone have any usefull (easy) advice on setting up the damping on a
Mini Lehman.  I`ve read Loads of articles on this subject ,And as far as I can see
The ideal amount is 0.7 - 0.8 and that means that if I walk up to the seismograph
and the pen deflects 10mm ,then the pen should return 0.5mm in the opposite direction
then back to zero. Is it me, or does this seem like too much. I feel i`m going to miss
the more distant Quakes, on the other hand ,I dont want the machine swinging wildly
after every bump. Im just after general advice. Any would be much appreciated!.
 
        Thanks In advance
                                 James 
Subject: Re: Mini Lehman Damping From: ChrisAtUpw@....... Date: Wed, 11 Jun 2008 14:24:07 EDT In a message dated 2008/06/11, jamesridout@.............. writes: > And as far as I can see The ideal amount is 0.7 - 0.8 and that means that > if I walk up to the seismograph and the pen deflects 10mm, then the pen should > return 0.5mm in the opposite direction then back to zero. Is it me, or does > this seem like too much. Hi James, I draw a thin black line on a sticky label and mount it vertical on the end of the mass. Over the top of this, separated by maybe 1/16", I mount a clear plastic ruler. I use a x2.5 mounted magnifying glass to view the ruler and the vertical line. I move the ruler so that the line is on a cm ruler mark. I use a rod or ruler as a lever resting on the baseplate to slowly move the mass 10 mm to one side. I remove the lever and watch what happens to the mass line. It should go past the rest postion by ~0.5 mm and then return to the rest postion. The magnifying glass makes this fairly easy to observe. Regards, Chris Chapman In a me= ssage dated 2008/06/11, jamesridout@.............. writes:

And as far as I can see The ide= al amount is 0.7 - 0.8 and that means that if I walk up to the seismograph a= nd the pen deflects 10mm, then the pen should return 0.5mm in the opposite d= irection then back to zero. Is it me, or does this seem like too much.

Hi James,

       I draw a thin black line on a sticky la= bel and mount it vertical on the end of the mass.
       Over the top of this, separated by mayb= e 1/16", I mount a clear plastic ruler.
       I use a x2.5 mounted magnifying glass t= o view the ruler and the vertical line.
       I move the ruler so that the line is on= a cm ruler mark.
       I use a rod or ruler as a lever resting= on the baseplate to slowly move the mass 10 mm to one side.
       I remove the lever and watch what happe= ns to the mass line.
       It should go past the rest postion by ~= 0.5 mm and then return to the rest postion.
       The magnifying glass makes this fairly=20= easy to observe.

       Regards,

       Chris Chapman
Subject: Re: Mini Lehman Damping From: John Lahr johnjan@........ Date: Wed, 11 Jun 2008 18:53:38 -0700 Hi James, Keep in mind that the damping/overshoot measurement is made directly on the mass, not by reading the pen motion. The pen motion is based on the velocity of the coil within a magnetic field and is further modified by your amplifier filters. Cheers, John At 11:24 AM 6/11/2008, you wrote: >In a message dated 2008/06/11, jamesridout@.............. writes: > >>And as far as I can see The ideal amount is 0.7 - 0.8 and that >>means that if I walk up to the seismograph and the pen deflects >>10mm, then the pen should return 0.5mm in the opposite direction >>then back to zero. Is it me, or does this seem like too much. > > >Hi James, > > I draw a thin black line on a sticky label and mount it > vertical on the end of the mass. > Over the top of this, separated by maybe 1/16", I mount a > clear plastic ruler. > I use a x2.5 mounted magnifying glass to view the ruler and > the vertical line. > I move the ruler so that the line is on a cm ruler mark. > I use a rod or ruler as a lever resting on the baseplate to > slowly move the mass 10 mm to one side. > I remove the lever and watch what happens to the mass line. > It should go past the rest postion by ~0.5 mm and then > return to the rest postion. > The magnifying glass makes this fairly easy to observe. > > Regards, > > Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mini Lehman Damping From: JAMES RIDOUT jamesridout@.............. Date: Thu, 12 Jun 2008 06:55:58 +0100 (BST) Hi, This is a link to a picture of my mini lehman, It is one I made from bits of scrap aluminium from work. It has a NeFe 3/4" x 1.5" magnet inside a coil of 6000 turns of 0.18mm enamelled copper wire, coupled directly to a chart recorder on the 50Mv setting NO amplification or filters ( is this wrong????). I pick up constant microseisisms all the time at about 5 secs period. The unit I have managed to tune to 15 seconds, and still be quite stable. James http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=7080078
Hi,
This is a link to a picture of my mini lehman, It is one I made from bits of scrap aluminium
      from work. It has a NeFe 3/4" x 1.5" magnet inside a coil of 6000 turns of 0.18mm
enamelled copper wire, coupled directly to a chart recorder on the 50Mv setting NO amplification or filters ( is this wrong????). I pick up constant microseisisms all the time
 at about 5 secs period. The unit I have managed to tune to 15 seconds, and still be
quite stable.
                       James
Subject: Re: Mini Lehman Damping From: ChrisAtUpw@....... Date: Thu, 12 Jun 2008 09:39:21 EDT In a message dated 2008/06/12, jamesridout@.............. writes: > This is a link to a picture of my mini lehman, It is one I made from bits=20 > of scrap aluminium from work. It has a NeFe 3/4" x 1.5" magnet inside a co= il=20 > of 6000 turns of 0.18mm enamelled copper wire, coupled directly to a chart= =20 > recorder on the 50Mv setting NO amplification or filters ( is this wrong??= ??). I=20 > pick up constant microseisisms all the time at about 5 secs period. The=20 > unit I have managed to tune to 15 seconds, and still be quite stable. Hi James, Thanks for the photo. Good on the period! I run at between 20 to 30 seconds, since most of=20 the Love and Rayleigh waves come in at ~20 seconds period. The viscosity of oil changes by x10 every 20 C Degrees, so oil=20 damping, apart from being messy and non linear is only good after it has bee= n set up=20 for a +/-2 C Deg operating range =3D unsatisfactory in my book! The=20 professionals dropped it in the 1940s. Then some idiot put a design on PSN i= n the early=20 1980s and they have been coping it ever since. It is difficult to set up and= it=20 gives poor + variable results. Magnet + plate damping is dead easy now that NdFeB magnets are readil= y=20 available and it is independant of temperature. The =A3315 SEP seismometer which plugs straight into a PC is shown at= =20 http://www.bgs.ac.uk/education/school_seismology/seismometer.html You get the AmaSeis recording and display program free and the=20 amplifier, filters and ADC converter are included. The computer processing=20= allows=20 you to filter the traces and remove microseisms on screen. Magnetic damping was used on the first Lehman. More information is=20 available at http://jclahr.com/science/psn/chapman/index.html A good amplifier is shown at=20 http://jclahr.com/science/psn/cochrane/index.html You need to restrict the max frequency to about 5 Hz to remove the=20 large amounts of environmental noise above about 10 Hz. http://www.sara.pg.it/sara_en.html in Italy also sell amateur seismi= c=20 equipment. Their list does not cover all the products that they supply. Maur= o=20 Mariotti is very helpful. Let me know if you need any help or advice. Best Wishes, Chris Chapman =20 In a me= ssage dated 2008/06/12, jamesridout@.............. writes:

This is a link to a picture of=20= my mini lehman, It is one I made from bits of scrap aluminium from work. It=20= has a NeFe 3/4" x 1.5" magnet inside a coil of 6000 turns of 0.18mm enamelle= d copper wire, coupled directly to a chart recorder on the 50Mv setti= ng NO amplification or filters ( is this wrong????). I pick up constant micr= oseisisms all the time  at about 5 secs period. The unit I have managed= to tune to 15 seconds, and still be quite stable.


Hi James,

       Thanks for the photo.
       Good on the period! I run at between 20= to 30 seconds, since most of the Love and Rayleigh waves come in at ~20 sec= onds period.
       The viscosity of oil changes by x10 eve= ry 20 C Degrees, so oil damping, apart from being messy and non linear is on= ly good after it has been set up for a +/-2 C Deg operating range =3D unsati= sfactory in my book! The professionals dropped it in the 1940s. Then some id= iot put a design on PSN in the early 1980s and they have been coping it ever= since. It is difficult to set up and it gives poor + variable results.
       Magnet + plate damping is dead easy now= that NdFeB magnets are readily available and it is independant of temperatu= re.
       The =A3315 SEP seismometer which plugs=20= straight into a PC is shown at http://www.bgs.ac.uk/education/school_seismol= ogy/seismometer.html
       You get the AmaSeis recording and displ= ay program free and the amplifier, filters  and ADC converter are inclu= ded. The computer processing allows you to filter the traces and remove micr= oseisms on screen.
       Magnetic damping was used on the first=20= Lehman. More information is available at http://jclahr.com/science/psn/chapm= an/index.html
       A good amplifier is shown at http://jcl= ahr.com/science/psn/cochrane/index.html
       You need to restrict the max frequency=20= to about 5 Hz to remove the large amounts of environmental noise above about= 10 Hz.
        http://www.sara.pg.it/sara_en.htm= l in Italy also sell amateur seismic equipment. Their list does not cover al= l the products that they supply. Mauro Mariotti is very helpful.

       Let me know if you need any help or adv= ice.

       Best Wishes,

       Chris Chapman
Subject: Hekla station online From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 12 Jun 2008 16:31:43 +0000 Hi all My sensor that is close to Hekla is now online and working. If there is an eruption in Hekla it is going to show on that sensor, as it just ~10 km from the center of the volcano. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Thu, 12 Jun 2008 19:25:52 EDT In a message dated 2008/06/11, paleoartifact@......... writes: Hi Meredith, It may be worthwhile looking for scribers with tungsten carbide points. These are round rods which can be bought seperately. Regards, Chris Chapman In a me= ssage dated 2008/06/11, paleoartifact@......... writes:

Hi Meredith,

       It may be worthwhile looking for scribe= rs with tungsten carbide points. These are round rods which can be bought se= perately.

       Regards,

       Chris Chapman
Subject: Re: Tungsten Pins From: Mark Robinson mark.robinson@............... Date: Fri, 13 Jun 2008 19:33:05 +1200 ChrisAtUpw@....... wrote: > It may be worthwhile looking for scribers with tungsten carbide > points. These are round rods which can be bought seperately. Are TIG welding electrodes any good ? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Fri, 13 Jun 2008 11:06:46 EDT In a message dated 2008/06/13, mark.robinson@............... writes: > ChrisAtUpw@....... wrote: > > It may be worthwhile looking for scribers with tungsten carbide > > points. These are round rods which can be bought seperately. > > Are TIG welding electrodes any good ? Hi Mark, No good at all. They are ~pure tungsten metal, not tungsten carbide. Regards, Chris Chapman In a me= ssage dated 2008/06/13, mark.robinson@............... writes:

ChrisAtUpw@....... wrote:
>        It may be worthwhile looking=20= for scribers with tungsten carbide
> points. These are round rods which can be bought seperately.

Are TIG welding electrodes any good ?


Hi Mark,

       No good at all. They are ~pure tungsten= metal, not tungsten carbide.

       Regards,

       Chris Chapman
Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Fri, 13 Jun 2008 10:37:21 -0600 Hi Chris and all, Its getting far wider; as too the variety of merchandise that is made from carbide now; from jewelry to fishing sinkers and "beyond". For "one" (USA ?) basic carbide's grade chart guide; as too what they mean, go by industry code and the basic carbide grade: http://www.basiccarbide.com/gchart.htm Hmmm, those ebay Mitsubishi carbide rods sold by "machprodinc" are a C4; (or BC-3) which according to the chart above have the BEST wear resistance of all the grades. It has no cutting "shock" resistance, but we don't care about that for seismo pivot bearings. They have a "ultra-fine grain" therein, but nothing refers to the ground "finish" itself. The photo rods "look" to be fine ground to me, but...I suppose it really depends on the eye of the beholder. It would then "seem" like these rods would easily endure or outlast the (whatever) ball bearings used on a seismo pivot. As far as "polish" on carbide, some sites sell 1-3 foot "polished" carbide...whatever that really is; which could range from some grinding to a partial polish to whatever. I haven't noted any web site, with any smaller length reasonable mirror finish rods that sells them. Dale Hardys suggested VCR VHS capstan, rod salvage still looks inviting. Mitsubishi has their own in-house grade, and they call them grade MF10. The C4 grade is a USA specific grade. All this means is one needs some reference to their countries grades and some other countries grade direct comparison specifics. http://blank.mitsubishicarbide.com/mmc/en/product/material/index.htm Centennial Carbide wrote in a reply email that their carbide is a "class2/10 carbide with a 10% cobalt binder", and is chinese made....with no China company name mentioned. Which of course (?) leaves it all as undefined as to wear resistance....but it would seem to be less than Mitsubishi mentioned above....but far better than any typical variety of steel rods. Again; their ultra-micrograin rods are just a grain size, not the finish itself. I "think" they buy from Pacificarbide. Inc., which is a California USA agent for a China company...but its a guess. On the other hand alot of chinese products have improved their quality over time. http://www.centennialcarbide.com Take care, Meredith Hi Chris and all,

Its getting far wider; as too the variety of merchandise that is made from carbide now; from jewelry to fishing sinkers and "beyond".

For "one" (USA ?) basic carbide's grade chart guide; as too what they mean, go by industry code and the basic carbide grade:

http://www.basiccarbide.com/gchart.htm

Hmmm, those ebay Mitsubishi carbide rods sold by "machprodinc" are a C4; (or BC-3) which according to the chart
above have the BEST wear resistance of all the grades.  It has no cutting "shock" resistance, but we don't care
about that for seismo pivot bearings.  They have a "ultra-fine grain" therein, but nothing refers to the ground "finish" itself.
The photo rods "look" to be fine ground to me, but...I suppose it really depends on the eye of the beholder.  It would then "seem"
like these rods would easily endure or outlast the (whatever) ball bearings used on a seismo pivot. 

As far as "polish" on carbide, some sites sell 1-3 foot "polished" carbide...whatever that really is; which could range from
some grinding to a partial polish to whatever.  I haven't noted any web site, with any smaller length reasonable mirror finish
rods that sells them.  Dale Hardys suggested VCR VHS capstan, rod salvage still looks inviting. 
 
Mitsubishi has their own in-house grade, and they call them grade MF10.   The C4 grade is a USA specific grade.
All this means is one needs some reference to their countries grades and some other countries grade direct
comparison specifics.

http://blank.mitsubishicarbide.com/mmc/en/product/material/index.htm

Centennial Carbide wrote in a reply email that their carbide is a "class2/10 carbide with a 10% cobalt binder", and
is chinese made....with no China company name mentioned.  Which of course (?) leaves it all as undefined as to wear
resistance....but it would seem to be less than Mitsubishi mentioned above....but far better than any typical variety of steel
rods.   Again; their ultra-micrograin rods are just a grain size, not the finish itself.  I "think" they buy from Pacificarbide. Inc.,
which is a California USA agent for a China company...but its a guess.  On the other hand alot of chinese products
have improved their quality over time.

http://www.centennialcarbide.com

Take care, Meredith







 


Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Fri, 13 Jun 2008 12:33:10 -0600 Hi all, Of course the VHS cassettes themselves contain a capstan ultra fine finish stainless steel small rod. There is probably multi-billions of these close to obsolete cassettes. For a simple trial "economy" dual rod and single ball pivot they might be interesting to just salvage and try out; and then eventually "graduate" to carbide rods. See: http//seismometer.googlepages.com/vhsrod Take care, Meredith On Tue, Jun 10, 2008 at 5:10 PM, Dale Hardy wrote: > > > The auction is for 50 of them < > I use the shafts salvaged from capstan motors from VCR machines, they > are Tungsten carbide approx 50mm long and 3mm diameter and Very highly > polished ( mirror finish ) > Check your local electronics repairer ( if they exist in your area :) dying > breed nowdays) > Dale > > Hi all,

Of course the VHS cassettes themselves contain a capstan ultra fine finish stainless steel small rod.  There is probably multi-billions
of these close to obsolete cassettes.  For a simple trial "economy" dual rod and single ball pivot they might be interesting to just salvage
and try out; and then eventually "graduate" to carbide rods.  See:

http//seismometer.googlepages.com/vhsrod

Take care, Meredith

On Tue, Jun 10, 2008 at 5:10 PM, Dale Hardy <photon1@...........> wrote:
 
<there is none anywhere I know of that are ground and diamond POLISHED.  The auction is for 50 of them <
I use the shafts salvaged from capstan motors from VCR machines, they are Tungsten carbide approx 50mm long and 3mm diameter and Very highly polished ( mirror finish )
Check your local electronics repairer ( if they exist in your area :) dying breed nowdays)
Dale

Subject: Re: A coil or dampening plate "drop down" assembly From: ChrisAtUpw@....... Date: Fri, 13 Jun 2008 17:01:08 EDT In a message dated 2008/06/08, paleoartifact@......... writes: > Below is a web page reference to a possible useful coil drop down (from the > boom) approach you might consider to use with your possible 4 neodymium > magnets and plates setup. It could be considered "risky" for the coil but thats > dependent on your visual alignment skill. Hi Meredith, I would be inclined to make the fitting the same width as the coil and then stick mylar film over both. This should work. It is about 2 thou thick and it can be bought as 'copy film' for Laser Printers. Maybe use a U loop to enclose the coil? You can make adhesives stick to the polythene coil former if you use a small blue flame to just melt the surfaces for a second where you want the glue to stick. This is how they get printing ink to stick on polythene containers.- the flame replaces the C-H3 bonds in the surface with COOH. When I use these sort of coils, I use a countersunk nylon bolt to fix them to a strip of glass circuit board. It adds 0.063" to the thickness. The former is 0.445" wide, including the two 0.040" cheeks, so the coil is about 0.365" wide. You need to allow about 0.04" clearance to the magnets, maybe a bit less per side, making a minimum of 0.525". Adding 0.063" is not going to make a huge difference. Regards, Chris In a me= ssage dated 2008/06/08, paleoartifact@......... writes:

Below is a web page reference t= o a possible useful coil drop down (from the boom) approach you might consid= er to use with your possible 4 neodymium magnets and plates setup.  It=20= could be considered "risky" for the coil but thats dependent on your visual=20= alignment skill.


Hi Meredith,

       I would be inclined to make the fitting= the same width as the coil and then stick mylar film over both. This should= work. It is about 2 thou thick and it can be bought as 'copy film' for Lase= r Printers. Maybe use a U loop to enclose the coil?

       You can make adhesives stick to the pol= ythene coil former if you use a small blue flame to just melt the surfaces f= or a second where you want the glue to stick. This is how they get printing=20= ink to stick on polythene containers.- the flame replaces the C-H3 bonds in=20= the surface with COOH.

       When I use these sort of coils, I use a= countersunk nylon bolt to fix them to a strip of glass circuit board. It ad= ds 0.063" to the thickness. The former is 0.445" wide, including the two 0.0= 40" cheeks, so the coil is about 0.365" wide. You need to allow about 0.04"=20= clearance to the magnets, maybe a bit less per side, making a minimum of 0.5= 25". Adding 0.063" is not going to make a huge difference.

       Regards,
      
       Chris
Subject: Re: Tungsten Pins From: Charles Patton charles.r.patton@........ Date: Fri, 13 Jun 2008 16:40:58 -0700 Another place to get carbide rods is: http://www.goldmine-elec-products.com They have individual carbide drill and router bits at $0.99 apiece. They also pretty much always have a grab bag of bits. I just checked and item no. G13259 is a bag of 8 or so bits for $2 -- a great deal. I've bought these over the years from Goldmine to use in my Dremel tool. They're a great bargain. When the Dremel HS steel burrs and router are used on steel, they dull instantly, whereas the carbide bits keep on taking away metal. They're the only bits I use. I tend to break them faster than I wear them out. With regards to seismo pivots, the shanks are a consistent 1/8" size for everything and the router bit were mirror polished in the last batch I bought maybe six months ago so you might not even have to polish them. So far as I can figure they're very good, micro-grain carbide bits that come out of the circuit board industry. Anyway, just another thought. Regards, Charles Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mini Lehman Damping From: "Connie & Jim Lehman" lehmancj@........... Date: Fri, 13 Jun 2008 20:12:06 -0400 James--a very interesting design-working into a chart recorder = directly. This reminds me of the early days of working with the = system--before building an amplifier with two 741 op amps. With liquid = damping--it is easy to be overdamped. Go magnetic damping as = suggested--you will be able to "tune" easily for optimum performance. = As for filtering--there is alot of ideas out there--I only filtered the = mechanical frequencies, and AC--40 to 60 cycles with a passive = filter---let the microseisms come through--their changes were = entertaining between events!! Keep up the good work, Jim Lehman ----- Original Message -----=20 From: JAMES RIDOUT=20 To: PSN-L@................. Sent: Thursday, June 12, 2008 1:55 AM Subject: Re: Mini Lehman Damping Hi,=20 This is a link to a picture of my mini lehman, It is one I made from = bits of scrap aluminium=20 from work. It has a NeFe 3/4" x 1.5" magnet inside a coil of = 6000 turns of 0.18mm=20 enamelled copper wire, coupled directly to a chart recorder on the = 50Mv setting NO amplification or filters ( is this wrong????). I pick up = constant microseisisms all the time at about 5 secs period. The unit I have managed to tune to 15 = seconds, and still be quite stable. James = http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=3D7080078 =20
  James--a very = interesting=20 design-working into a chart recorder directly.  This reminds me of = the=20 early days of working with the system--before building an amplifier with = two 741=20 op amps.  With liquid damping--it is easy to be overdamped.  = Go=20 magnetic damping as suggested--you will be able to "tune" easily for = optimum=20 performance.  As for filtering--there is alot of ideas out there--I = only=20 filtered the mechanical frequencies, and AC--40 to 60 cycles with a = passive=20 filter---let the microseisms come through--their changes were = entertaining=20 between events!!
   Keep up the good=20 work,   Jim Lehman
----- Original Message -----
From:=20 JAMES RIDOUT
Sent: Thursday, June 12, 2008 = 1:55=20 AM
Subject: Re: Mini Lehman = Damping

Hi,
This is a link to a picture of my mini lehman, It is one I made = from bits=20 of scrap aluminium
      from work. It has a NeFe 3/4" x = 1.5"=20 magnet inside a coil of 6000 turns of 0.18mm
enamelled copper wire, coupled directly to a chart = recorder on the=20 50Mv setting NO amplification or filters ( is this wrong????). I pick = up=20 constant microseisisms all the time
 at about 5 secs period. The unit I have managed to tune to = 15=20 seconds, and still be
quite stable.
=
           &n= bsp;          =20 James
http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=3D7= 080078

 =20
Subject: Re: Mini Lehman Damping From: "meredith lamb" paleoartifact@......... Date: Fri, 13 Jun 2008 19:54:49 -0600 Hi all, Magnetic dampening on iron can be quite more adjustable than the coil pickup assembly. One can put on additional neodymium magnets and in whatever (limited) quanity, varible rating, to make it work with your seismo. The "key" or strongest dampening area is simply the joints (edges) between the mounted magnets as it is here where the "magnetic arching crossover" field is the strongest, and hence the eddy current. Another way of putting it is that its not the center/broad area of the individual magnets where the very strongest eddy current is induced in your aluminum/copper; its the area immediately near the (crossover) joints thereof. I put up another brief web page for this subject, see: http://seismometer.googlepages.com/magnetdampening Take care, Meredith Lamb On Fri, Jun 13, 2008 at 6:12 PM, Connie & Jim Lehman wrote: > * James--a very interesting design-working into a chart recorder > directly. This reminds me of the early days of working with the > system--before building an amplifier with two 741 op amps. With liquid > damping--it is easy to be overdamped. Go magnetic damping as suggested--you > will be able to "tune" easily for optimum performance. As for > filtering--there is alot of ideas out there--I only filtered the mechanical > frequencies, and AC--40 to 60 cycles with a passive filter---let the > microseisms come through--their changes were entertaining between events!! > * > * Keep up the good work, Jim Lehman* > > ----- Original Message ----- > *From:* JAMES RIDOUT > *To:* PSN-L@.............. > *Sent:* Thursday, June 12, 2008 1:55 AM > *Subject:* Re: Mini Lehman Damping > > Hi, > This is a link to a picture of my mini lehman, It is one I made from bits > of scrap aluminium > from work. It has a NeFe 3/4" x 1.5" magnet inside a coil of 6000 > turns of 0.18mm > enamelled copper wire, coupled *directly* to a chart recorder on the 50Mv > setting NO amplification or filters ( is this wrong????). I pick up constant > microseisisms all the time > at about 5 secs period. The unit I have managed to tune to 15 seconds, and > still be > quite stable. > James > http://www.freewebs.com/jridout/apps/photos/photo.jsp?photoID=7080078 > > > > Hi all,

Magnetic dampening on iron can be quite more adjustable than the coil pickup assembly.  One can put on additional neodymium
magnets and in whatever (limited) quanity, varible rating, to make it work with your seismo.  The "key" or strongest dampening area is simply
the joints (edges) between the mounted magnets as it is here where the "magnetic arching crossover" field is the strongest, and hence the eddy
current.  Another way of putting it is that its not the center/broad area of the individual magnets where the very strongest eddy current is induced in
your aluminum/copper; its the area immediately near the (crossover) joints thereof. 

I put up another brief web page for this subject, see:

http://seismometer.googlepages.com/magnetdampening

Take care, Meredith Lamb

On Fri, Jun 13, 2008 at 6:12 PM, Connie & Jim Lehman <lehmancj@...........> wrote:
  James--a very interesting design-working into a chart recorder directly.  This reminds me of the early days of working with the system--before building an amplifier with two 741 op amps.  With liquid damping--it is easy to be overdamped.  Go magnetic damping as suggested--you will be able to "tune" easily for optimum performance.  As for filtering--there is alot of ideas out there--I only filtered the mechanical frequencies, and AC--40 to 60 cycles with a passive filter---let the microseisms come through--their changes were entertaining between events!!
   Keep up the good work,   Jim Lehman
----- Original Message -----
From: JAMES RIDOUT
Sent: Thursday, June 12, 2008 1:55 AM
Subject: Re: Mini Lehman Damping

Hi,
This is a link to a picture of my mini lehman, It is one I made from bits of scrap aluminium
      from work. It has a NeFe 3/4" x 1.5" magnet inside a coil of 6000 turns of 0.18mm
enamelled copper wire, coupled directly to a chart recorder on the 50Mv setting NO amplification or filters ( is this wrong????). I pick up constant microseisisms all the time
 at about 5 secs period. The unit I have managed to tune to 15 seconds, and still be
quite stable.
                       James

Subject: Re: A coil or dampening plate "drop down" assembly From: "meredith lamb" paleoartifact@......... Date: Fri, 13 Jun 2008 20:03:29 -0600 Hi Chris, You have a quite interesting variety of means of attachments! Take care, Meredith Lamb On Fri, Jun 13, 2008 at 3:01 PM, wrote: > In a message dated 2008/06/08, paleoartifact@......... writes: > > Below is a web page reference to a possible useful coil drop down (from the > boom) approach you might consider to use with your possible 4 neodymium > magnets and plates setup. It could be considered "risky" for the coil but > thats dependent on your visual alignment skill. > > > > Hi Meredith, > > I would be inclined to make the fitting the same width as the coil > and then stick mylar film over both. This should work. It is about 2 thou > thick and it can be bought as 'copy film' for Laser Printers. Maybe use a U > loop to enclose the coil? > > You can make adhesives stick to the polythene coil former if you use > a small blue flame to just melt the surfaces for a second where you want the > glue to stick. This is how they get printing ink to stick on polythene > containers.- the flame replaces the C-H3 bonds in the surface with COOH. > > When I use these sort of coils, I use a countersunk nylon bolt to > fix them to a strip of glass circuit board. It adds 0.063" to the thickness. > The former is 0.445" wide, including the two 0.040" cheeks, so the coil is > about 0.365" wide. You need to allow about 0.04" clearance to the magnets, > maybe a bit less per side, making a minimum of 0.525". Adding 0.063" is not > going to make a huge difference. > > Regards, > > Chris > Hi Chris,

You have a quite interesting variety of means of attachments!

Take care, Meredith Lamb

On Fri, Jun 13, 2008 at 3:01 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/06/08, paleoartifact@......... writes:

Below is a web page reference to a possible useful coil drop down (from the boom) approach you might consider to use with your possible 4 neodymium magnets and plates setup.  It could be considered "risky" for the coil but thats dependent on your visual alignment skill.


Hi Meredith,

       I would be inclined to make the fitting the same width as the coil and then stick mylar film over both. This should work. It is about 2 thou thick and it can be bought as 'copy film' for Laser Printers. Maybe use a U loop to enclose the coil?

       You can make adhesives stick to the polythene coil former if you use a small blue flame to just melt the surfaces for a second where you want the glue to stick. This is how they get printing ink to stick on polythene containers.- the flame replaces the C-H3 bonds in the surface with COOH.

       When I use these sort of coils, I use a countersunk nylon bolt to fix them to a strip of glass circuit board. It adds 0.063" to the thickness. The former is 0.445" wide, including the two 0.040" cheeks, so the coil is about 0.365" wide. You need to allow about 0.04" clearance to the magnets, maybe a bit less per side, making a minimum of 0.525". Adding 0.063" is not going to make a huge difference.

       Regards,
      
       Chris

Subject: Re: Mini Lehman Damping From: ChrisAtUpw@....... Date: Fri, 13 Jun 2008 23:14:40 EDT In a message dated 2008/06/14, paleoartifact@......... writes: > The "key" or strongest dampening area is simply the joints (edges) between > the mounted magnets as it is here where the "magnetic arching crossover" > field is the strongest, and hence the eddy current. Another way of putting it is > that its not the center/broad area of the individual magnets where the very > strongest eddy current is induced in your aluminum/copper; its the area > immediately near the (crossover) joints thereof. > > I put up another brief web page for this subject, see: > > http://seismometer.googlepages.com/magnetdampening Hi Meredith, If you put your magnets on the backing plate in even numbers, you get a slightly higher internal field, but also a much reduced stray field from the backing plates. An odd number of magnets has to return the field of one magnet between the backing plates around the edges of the magnets, or through the mounting bolts, rather than directly between the closer magnet surfaces, when they are mounted in pairs. It is the length of the N/S edge junctions which provides most of the damping. If you use rectangular magnets, mount the longest edges next to one another. The greatest damping is when the plate moves perpendicular to this direction. The damping plate should overlap the magnets by about half this length to get the greatest effect. I prefer to use a Copper damping plate. Aluminum is slightly paramagnetic and you can get appreciable forces on the damping plate if it's edge moves close to the edges of the magnets. This can cause the system to be slightly unstable in operation and make the arm 'skate off' to the stops beyond a moderate deflection. Regards, Chris Chapman In a me= ssage dated 2008/06/14, paleoartifact@......... writes:

The "key" or strongest dampenin= g area is simply the joints (edges) between the mounted magnets as it is her= e where the "magnetic arching crossover" field is the strongest, and hence t= he eddy current.  Another way of putting it is that its not the center/= broad area of the individual magnets where the very strongest eddy current i= s induced in your aluminum/copper; its the area immediately near the (crosso= ver) joints thereof. 

I put up another brief web page for this subject, see:

http://seismo= meter.googlepages.com/magnetdampening


Hi Meredith,

       If you put your magnets on the backing=20= plate in even numbers, you get a slightly higher internal field, but also a=20= much reduced stray field from the backing plates.

       An odd number of magnets has to return=20= the field of one magnet between the backing plates around the edges of the m= agnets, or through the mounting bolts, rather than directly between the clos= er magnet surfaces, when they are mounted in pairs.

       It is the length of the N/S edge juncti= ons which provides most of the damping. If you use rectangular magnets, moun= t the longest edges next to one another. The greatest damping is when the pl= ate moves perpendicular to this direction. The damping plate should overlap=20= the magnets by about half this length to get the greatest effect.

       I prefer to use a Copper damping plate.= Aluminum is slightly paramagnetic and you can get appreciable forces on the= damping plate if it's edge moves close to the edges of the magnets. This ca= n cause the system to be slightly unstable in operation and make the arm 'sk= ate off' to the stops beyond a moderate deflection.

       Regards,

       Chris Chapman
Subject: How to download SAC binary files from IRIS From: Bobhelenmcclure@....... Date: Sat, 14 Jun 2008 16:59:38 EDT There are times when you might want to compare your event files with that=20 from a nearby network seismic station. You can do this by using the Wilbur I= I=20 facility at the IRIS web site. Here are the instructions for downloading data from a network station as=20 given to me by Bob Hancock when I first started using Wilber II. This proced= ure=20 is still good. Follow it strictly. Of course, select only the station(s) you= =20 want. (You have to unchecked the ones you don't want!) The best way to find=20= a=20 particular event is to select "List All Events". The only thing I do not lik= e=20 about Wilber II is that they don't give you a chance to review your request=20 before they go to work on it, so you have to select events, stations, and fi= le=20 type SAC BINARY very carefully. 1. Access IRIS http://dmc.iris.washington.edu/ 2. Select Earthquakes http://dmc.iris.washington.edu/quakes/quakes.htm 3. Select Wilber II =20 http://dmc.iris.washington.edu/cgi-bin/wilberII_page1.pl 4. Select List all events (upper right side) 5 Scroll down to event and click on it 6. Click on the network for the station you want, then click on Proceed at=20 bottom of page 7. Unselect the stations you do not want =E2=80=93 Make sure the desired st= ation is=20 selected. 8. On left side of page select BHE, BHN, and BHZ 9. Check SAC BINARY Individual Files on lower left !!!!! 10. Bottom middle =E2=80=93 check time before and after P Wave. However, si= nce you=20 are requesting the SPYDER File, it will only be 60 minutes long. You have to= =20 wait 60 to 90 days for the FARM file to get more than 60 minutes. 11. Bottom right =E2=80=93 Enter a user name, and a request name (event name= and date=20 are good to use). Enter your name and email address, and don=E2=80=99t forge= t to=20 check to be notified when the file is ready. You don't always get an email,=20= so=20 keep looking at the progress screen. It takes about 5 minutes at most to get= the=20 files. You can download them to your computer. The URL for your data will b= e:=20 ftp://ftp.iris.washington.edu/pub/userdata/[user name]/[request name]. Please use my utility SAC_to_PSN for conversion. You will have to modify=20 the PSN file to "Sensor Type=3DVelocity" and enter the correct magnitude. Al= so,=20 select "Sensor Units" for "Y-Scale Display Mode". Find my utility at=20 http://bobmcclure90.googlepages.com/winsac WinQuake can load SAC files, and also do the conversion, but you will not=20 get the sensor sensitivity number. My utility also transfers magnitude, but=20= it=20 is never given on the network files. Sensor Type is also never defined on SA= C=20 files. If you use WinQuake to load and view SAC files, never try to crop or=20 downsample them. Save them as PSN files, and thereafter use the PSN files fo= r=20 further processing.=20 Cheers, Bob ************** Vote for your city's best dining and nightlife. City's Best=20 2008. (http://citysbest.aol.com?ncid=3Daolacg00050000000102)   There are times when you mig= ht want to compare your event files with that from a nearby network seismic=20= station. You can do this by using the Wilbur II facility at the IRIS web sit= e.

  Here are the instructions for downloading data from a network station= as given to me by Bob Hancock when I first started using Wilber II. This pr= ocedure is still good. Follow it strictly. Of course, select only the statio= n(s) you want. (You have to unchecked the ones you don't want!) The best way= to find a particular event is to select "List All Events". The only thing I= do not like about Wilber II is that they don't give you a chance to review=20= your request before they go to work on it, so you have to select events, sta= tions, and file type SAC BINARY very carefully.

1.  Access IRIS         &n= bsp;    http://dmc.iris.washington.edu/
2.  Select Earthquakes   http://dmc.iris.washington.edu/quake= s/quakes.htm
3.  Select Wilber II         ht= tp://dmc.iris.washington.edu/cgi-bin/wilberII_page1.pl
4.  Select List all events (upper right side)
5   Scroll down to event and click on it
6.  Click on the network for the station you want, then click on Procee= d at bottom of page
7.  Unselect the stations you do not want =E2=80=93 Make sure the desir= ed station is selected.
8.  On left side of page select BHE, BHN, and BHZ
9.  Check SAC BINARY Individual Files on lower left !!!!!
10. Bottom middle =E2=80=93 check time before and after P Wave.  Howeve= r, since you are requesting the SPYDER File, it will only be 60 minutes long= .. You have to wait 60 to 90 days for the FARM file to get more than 60 minut= es.
11. Bottom right =E2=80=93 Enter a user name, and a request name (event name= and date are good to use). Enter your name and email address, and don=E2= =80=99t forget to check to be notified when the file is ready. You don't alw= ays get an email, so keep looking at the progress screen. It takes about 5 m= inutes at most to get the files.  You can download them to your compute= r. The URL for your data will be: ftp://ftp.iris.washington.edu/pub/userdata= /[user name]/[request name].

  Please use my utility SAC_to_PSN for conversion. You will have to mod= ify the PSN file to "Sensor Type=3DVelocity" and enter the correct magnitude= .. Also, select "Sensor Units" for "Y-Scale Display Mode". Find my utility at=

http://bobmcclure90.googlepages.com/winsac

  WinQuake can load SAC files, and also do the conversion, but you will= not get the sensor sensitivity number. My utility also transfers magnitude,= but it is never given on the network files. Sensor Type is also never defin= ed on SAC files. If you use WinQuake to load and view SAC files, never try t= o crop or downsample them. Save them as PSN files, and thereafter use the PS= N files for further processing.

Cheers,

Bob




**************
Vote for your city's best dining and ni= ghtlife. City's Best 2008.
(http://citysbest.aol.com?ncid=3Daolacg0= 0050000000102) Subject: Re: How to download SAC binary files from IRIS From: Dave Nelson davenn@............... Date: Sun, 15 Jun 2008 10:51:54 +1000 Hi Bob, I tried to follow you instructings and didnt get far :( where do I select earthquakes, are you are inferring there is a list that I can select from ?? there isnt a list on quakes on that page am I clicking on one of those purple tabs at the top ? Home About IRIS Data Software instrumentation publications maybe the data one ? then to where ? can you pleae fill in some of the gaps in the instructions :)) cheers Dave N Sydney __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: How to download SAC binary files from IRIS From: Bob Hancock carpediem1@......... Date: Sat, 14 Jun 2008 18:06:37 -0700 Dave - Try this link. It takes you straight to Wilber II. http://www.iris.edu/dms/wilber.htm Bob Hancock On 6/14/08 5:51 PM, "Dave Nelson" wrote: > > Hi Bob, > I tried to follow you instructings and didnt get far :( > > where do I select earthquakes, are you are inferring there is a list that > I can > select from ?? there isnt a list on quakes on that page > > am I clicking on one of those purple tabs at the top ? > Home About IRIS Data Software instrumentation publications > > maybe the data one ? then to where ? > > can you pleae fill in some of the gaps in the instructions :)) > > cheers > Dave N > Sydney > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: How to download SAC binary files from IRIS From: Dave Nelson davenn@............... Date: Sun, 15 Jun 2008 11:51:03 +1000 Bob, ahhhh YES success first files downloaded dang have needed to do that for so long, got a lot of work ahead of me catching up with past several years of big events hahaha :) thanks so much Dave N At 06:06 PM 6/14/2008 -0700, you wrote: >Dave - >Try this link. It takes you straight to Wilber II. > http://www.iris.edu/dms/wilber.htm > >Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Sat, 14 Jun 2008 21:19:38 -0600 Hi Charles, Thanks for the info....in many ways the Electronic Goldmine; along with all their potentially useful electronic items; seems to be potentially one of the best; if not the only possible source of such mirror finishes. They do have a $10.00 minimum; not counting the freight charge. I checked the other 3-4 major electronic surplus's on the web...none have carbide drills/router bits that I noted. The useful router shank bits appear to be roughly ~1.25"; which is more than enough length. The cutting ends can usually be easily knocked off in a vise. They also appear to have acouple small di-sectible and relatively cheap 120AC relays...from which one "might" try to salvage the coil for a seismo. Alot of these relays are tough to retrieve the coil intact; without damage. Hmmm, the guy that owes/runs it used to be in Denver and was running a surplus many years back; but his name escapes me now. I know because he told me he was moving to Arizona before he left. Real nice guy. Of course it could be someone else running it now. Take care, Meredith On Fri, Jun 13, 2008 at 5:40 PM, Charles Patton wrote: > Another place to get carbide rods is: > http://www.goldmine-elec-products.com > They have individual carbide drill and router bits at $0.99 apiece. They > also pretty much always have a grab bag of bits. I just checked and item > no. G13259 is a bag of 8 or so bits for $2 -- a great deal. I've bought > these over the years from Goldmine to use in my Dremel tool. They're a great > bargain. When the Dremel HS steel burrs and router are used on steel, they > dull instantly, whereas the carbide bits keep on taking away metal. They're > the only bits I use. I tend to break them faster than I wear them out. > With regards to seismo pivots, the shanks are a consistent 1/8" size for > everything and the router bit were mirror polished in the last batch I > bought maybe six months ago so you might not even have to polish them. So > far as I can figure they're very good, micro-grain carbide bits that come > out of the circuit board industry. > > Anyway, just another thought. > Regards, > Charles Patton > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > Hi Charles,

Thanks for the info....in many ways the Electronic Goldmine; along with all their potentially
useful electronic items; seems to be potentially one of the best; if not the only possible source of such mirror
finishes.  They do have a $10.00 minimum; not counting the freight charge.

I checked the other 3-4 major electronic surplus's on the web...none have carbide drills/router bits that I noted.

The useful router shank bits appear to be roughly ~1.25"; which is more than enough length.  The cutting ends can
usually be easily knocked off in a vise.

They also appear to have acouple small di-sectible and relatively cheap 120AC relays...from which one "might" try to
salvage the coil for a seismo.  Alot of these relays are tough to retrieve the coil intact; without damage.

Hmmm, the guy that owes/runs it used to be in Denver and was running a surplus many years back; but his name escapes
me now.  I know because he told me he was moving to Arizona before he left.  Real nice guy.  Of course it could be
someone else running it now.

Take care, Meredith

On Fri, Jun 13, 2008 at 5:40 PM, Charles Patton <charles.r.patton@........> wrote:
Another place to get carbide rods is:
http://www.goldmine-elec-products.com
They have individual carbide drill and router bits at $0.99 apiece. They also pretty much always have a grab bag of bits.  I just checked and item no. G13259 is a bag of 8 or so bits for $2 -- a great deal. I've bought these over the years from Goldmine to use in my Dremel tool. They're a great bargain.  When the Dremel HS steel burrs and router are used on steel, they dull instantly, whereas the carbide bits keep on taking away metal.  They're the only bits I use.  I tend to break them faster than I wear them out.  With regards to seismo pivots, the shanks are a consistent 1/8" size for everything and the router bit were mirror polished in the last batch I bought maybe six months ago  so you might not even have to polish them.  So far as I can figure they're very good, micro-grain carbide bits that come out of the circuit board industry.

Anyway, just another thought.
Regards,
Charles Patton

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.

Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Sat, 14 Jun 2008 23:43:24 EDT In a message dated 2008/06/15, paleoartifact@......... writes: > I checked the other 3-4 major electronic surplus's on the web...none have > carbide drills/router bits that I noted. Hi Meredith, Smallparts stock carbide drills. Digikey also stock 1/8" shank drills, but they are more expensive. Regards, Chris In a me= ssage dated 2008/06/15, paleoartifact@......... writes:

I checked the other 3-4 major e= lectronic surplus's on the web...none have carbide drills/router bits that I= noted.


Hi Meredith,

       Smallparts stock carbide drills.
       Digikey also stock 1/8" shank drills, b= ut they are more expensive.

       Regards,

       Chris
Subject: adding event data to Winquake From: Dave Nelson davenn@............... Date: Sun, 15 Jun 2008 14:19:29 +1000 Hi gang, now that Bob has shown me how to d/l SAC event data to bring into Winquake. Is there a way to add the data for a given event without having to manually type it in over and over again for each station I download an event from ie. the date, time, mag, depth, lat long, etc data oce upon a time I vaguely remember maybe on the old PSN3 format once you added that data for the first station file then it would auto add it for every other file that you opened up that had the corresponding date and time its been so so long since I have done any of this. thamks Dave N __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Scientist water can evaluation From: "meredith lamb" paleoartifact@......... Date: Sat, 14 Jun 2008 23:34:13 -0600 I suppose every seismometry lab and kitchen, should have one of these......see: http://seismometer.googlepages.com/scientistwater (Just follow the directions on the photo can label....simple instructions...you too can figure it out I think...maybe....perhaps...sort of...) Think it was made around the 1950's....wonder if its edible now...or stale? Probably a good old weight loss diet perhaps... The "contents" are probably purer than todays ... The weld lining might have some lead in the weld....bad for the brains.... Save it for afew thousand years, for at mo spheric evaluation? Made in California.....is that really good? I don't think it would make a good seismometer mass...the can is ferromagnetic. Theres NO pull tab on top....what do we do now? Can it you say? Can the can? Do we need a professional or learned evaluation? Take care, (Whats his name) I suppose every seismometry lab and kitchen, should have one of these......see:

http://seismometer.googlepages.com/scientistwater

(Just follow the directions on the photo can label....simple instructions...you too can
figure it out I think...maybe....perhaps...sort of...)

Think it was made around the 1950's....wonder if its edible now...or stale?

Probably a good old weight loss diet perhaps...

The "contents" are probably purer than todays ...

The weld lining might have some lead in the weld....bad for the brains....

Save it for afew thousand years, for at mo spheric evaluation?

Made in California.....is that really good?

I don't think it would make a good seismometer mass...the can is ferromagnetic.

Theres NO pull tab on top....what do we do now?

Can it you say?  Can the can?

Do we need a professional or learned evaluation?


Take care,  (Whats his name)




Subject: Re: Scientist water can evaluation From: ChrisAtUpw@....... Date: Sun, 15 Jun 2008 11:04:24 EDT In a message dated 2008/06/15, paleoartifact@......... writes: > I suppose every seismometry lab and kitchen, should have one of > these......see: > http://seismometer.googlepages.com/scientistwater > (Just follow the directions on the photo can label....simple > instructions...you too can figure it out I think...maybe) Hi There, What is the chance of setting up a lot of canning factories in Iowa, Oklahoma, Texas, Wisconsin, Minnesota, Ohio and Missouri? Maybe just encourage the bottling plants to store it for future use? Got a drought in your garden? Buy your Storm Water here! Turn a catastrophy into an opportunuity? Chris In a me= ssage dated 2008/06/15, paleoartifact@......... writes:

I suppose every seismometry lab= and kitchen, should have one of these......see:
http://seismom= eter.googlepages.com/scientistwater
(Just follow the directions on the photo can label....simple instructions...= you too can figure it out I think...maybe)


Hi There,
      
       What is the chance of setting up a lot=20= of canning factories in Iowa, Oklahoma, Texas, Wisconsin, Minnesota, Ohio an= d Missouri? Maybe just encourage the bottling plants to store it for future=20= use?
       Got a drought in your garden? Buy your=20= Storm Water here!
       Turn a catastrophy into an opportunuity= ?

       Chris     &nbs= p;




Subject: Re: Scientist water can evaluation From: "Thomas Dick" dickthomas01@............. Date: Sun, 15 Jun 2008 11:58:34 -0500 Good idea Chris --- Indiana got it first, we will get more tonight, = rivers just cresting, farmers will be hard pressed to get any crops in = after this What is the chance of setting up a lot of canning factories in = Iowa, Oklahoma, Texas, Wisconsin, Minnesota, Ohio and Missouri? Maybe = just encourage the bottling plants to store it for future use?=20 Got a drought in your garden? Buy your Storm Water here! Turn a catastrophy into an opportunuity?
Good idea Chris --- Indiana got it = first, we will=20 get more tonight, rivers just cresting, farmers will be hard pressed to = get any=20 crops in after this

       What is the = chance of=20 setting up a lot of canning factories in Iowa, Oklahoma, Texas, = Wisconsin,=20 Minnesota, Ohio and Missouri? Maybe just encourage the bottling plants = to=20 store it for future use?
       Got = a=20 drought in your garden? Buy your Storm Water=20 here!
       Turn a catastrophy into = an=20 opportunuity?
Subject: Re: Scientist water can evaluation From: "meredith lamb" paleoartifact@......... Date: Sun, 15 Jun 2008 11:28:47 -0600 YO! Eh....Chris...probably not very good, especially if the state > governments gets involved; it would probably lose out after a very long and > protracted political battle even with heavy taxes at stake. Canned drinking alcohol products would be probably much more popular among the masses; which is already heavily taxed. Shipping would bump it up 2-3x in price of course. I wonder if corn floats? Eh...I think you would need something that involves personal greed and tax unreported treasure finds to enhance the "product". Eh...how about this "treasure lifter" product web page?: http://seismometer.googlepages.com/treasure Cheers, Meredith > > > Hi There, > > What is the chance of setting up a lot of canning factories in Iowa, > Oklahoma, Texas, Wisconsin, Minnesota, Ohio and Missouri? Maybe just > encourage the bottling plants to store it for future use? > Got a drought in your garden? Buy your Storm Water here! > Turn a catastrophy into an opportunuity? > > Chris > > > > >

YO!   Eh....Chris...probably not very good, especially if the state governments gets involved; it would probably lose out after a very long and protracted political battle
even with heavy taxes at stake.  Canned drinking alcohol products would be probably much more popular among the masses; which is already heavily taxed.  Shipping
would bump it up 2-3x in price of course.  I wonder if corn floats?

Eh...I think you would need something that involves personal greed and tax unreported treasure finds to enhance the "product".  Eh...how about this "treasure lifter" product
web page?:

http://seismometer.googlepages.com/treasure

Cheers,

Meredith
 


Hi There,
      
       What is the chance of setting up a lot of canning factories in Iowa, Oklahoma, Texas, Wisconsin, Minnesota, Ohio and Missouri? Maybe just encourage the bottling plants to store it for future use?
       Got a drought in your garden? Buy your Storm Water here!
       Turn a catastrophy into an opportunuity?

       Chris      





Subject: Re: Scientist water can evaluation From: tchannel1@............ Date: Sun, 15 Jun 2008 15:26:24 -0600 Let us not completely ignore the environmental repercussions of this = proposal. This obviously will, could, or might affect the balance of = ground water, surface water, and the great Snake River aquifer here in = Idaho. I have been in Idaho 34 years and all but two of those years the = Governor has declared a "Drought." Nobody seems to consider that this = area is a desert. Assuming the dehydrated water in the can contains at least some water, = taking this limited natural resource from this area could have profound = effects on an already fragile ecosystem. Taking the water from the mountain to the north is out of the question = because of the adverse effects on the slopes of road construction and = runoff into the creeks and watershed, hence on the fish and wildlife. = But being open minded about it, an environmental feasibility study could = be done. Taking the water from the Boise River is out of the question because of = the Wetland Habitat restrictions and, again ,the erosion factors along = the riverbanks. Many years ago the college kids would prospect for = gold in the rivers and streams, but the silt would muddied the water, = depressed the fish, so that is no longer allowed. Taking the water from the desert to the south of Boise I think would be = perfectly permitable, but there are numerous Native American petrographs = throughout the desert land, which has made it necessary to make great = regions of the desert off limits. We also have the "Bureau Snail," = which is unique to the area and is on the Endangered Species list, but a = feasibility study could be done. This vast area of land runs from Boise for hundreds of miles south, all = desert but a town now and then, like Reno and Winnemucca, Nevada. Keep = in mind you could not use ground water, because of the strain already on = the Snake River aquifer. Surface water would be okay if you could = locate some, once you attained the necessary environmental impact study, = and various State and Federal permits. After thinking out loud about this, I suggest it most likely can't be = done in Idaho because of our limited natural resources and our limited = renewable natural resources, like water. I don't think Idaho could offer to manufacture the cans. We used to = have lots of lead mines, but they are all gone. So even the lead for = soldering the can seams would not be feasible. If the label is made = from wood pulp, we would have to pass up the manufacturing of those, as = we no longer operate wood mills in Idaho. We have billions and = billions of trees, but because of restrictions they can't be harvested, = thinned, or put to good use, hence the pulp mills have closed. But, "where there is a will, there is a way." This Canned Water could = be marketed. I suggest we import the necessary "seed waters" from = Canada, in the same manner as we do for natural gas and oil products, or = from Venezuela, or the Middle East. I did some careful calculations and = cost analyses. We could process, can, and market the dehydrated water = for about $4.15 per gallon for regular dehydrated, and $4.85 for the = premium. This has nothing to do with earthquakes, so my apologies for taking up = space. Ted ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Saturday, June 14, 2008 11:34 PM Subject: Scientist water can evaluation I suppose every seismometry lab and kitchen, should have one of = these......see: http://seismometer.googlepages.com/scientistwater (Just follow the directions on the photo can label....simple = instructions...you too can figure it out I think...maybe....perhaps...sort of...) Think it was made around the 1950's....wonder if its edible now...or = stale? Probably a good old weight loss diet perhaps... The "contents" are probably purer than todays ... The weld lining might have some lead in the weld....bad for the = brains.... Save it for afew thousand years, for at mo spheric evaluation? Made in California.....is that really good? I don't think it would make a good seismometer mass...the can is = ferromagnetic. Theres NO pull tab on top....what do we do now? Can it you say? Can the can? Do we need a professional or learned evaluation? Take care, (Whats his name)
Let us not completely ignore the = environmental=20 repercussions of this proposal.   This obviously will, could, = or might=20 affect the balance of ground water, surface water, and the great Snake=20 River aquifer here in Idaho.  I have been in Idaho 34 years = and all=20 but two of those years the Governor has declared a "Drought."  = Nobody seems=20 to consider that this area is a desert.
Assuming the dehydrated water in the = can contains=20 at least some water, taking this limited natural resource from this area = could=20 have profound effects on an already fragile ecosystem.
 
Taking the water from the mountain to = the north is=20 out of the question because of the adverse effects on the slopes of road = construction and runoff into the creeks and watershed, hence on the = fish=20 and wildlife.  But being open = minded about=20 it, an environmental feasibility study could be done.
 
Taking the water from the Boise River = is out of the=20 question because of the Wetland Habitat restrictions and, again ,the = erosion=20 factors along the riverbanks.   Many years ago the college = kids would=20 prospect for gold in the rivers and streams, but the silt would muddied = the=20 water, depressed the fish, so that is no longer allowed.
 
Taking the water from the desert to the = south of=20 Boise I think would be perfectly permitable, but there are numerous = Native=20 American petrographs throughout the desert land, which has made it = necessary to=20 make great regions of the desert off limits.   We also = have the=20 "Bureau Snail," which is unique to the area and is on the Endangered = Species=20 list, but a feasibility study could be done.
 
This vast area of land runs from Boise = for hundreds=20 of miles south, all desert but a town now and then, like Reno and=20 Winnemucca, Nevada.  Keep in = mind you could=20 not use ground water, because of the strain already on the Snake River=20 aquifer.   Surface water would be okay if you could = locate some,=20 once you attained the necessary environmental impact study, and various = State=20 and Federal permits.
 
After thinking out loud about this, I = suggest it=20 most likely can't be done in Idaho because of our limited natural = resources and=20 our limited renewable natural resources, like water.
I don't think Idaho could offer to = manufacture the=20 cans.  We used to have lots of lead mines, but they are all = gone.  So=20 even the lead for soldering the can seams would not be feasible.  = If the=20 label is made from wood pulp, we would have to pass up the = manufacturing of=20 those, as we no longer operate wood mills in Idaho.   We have = billions=20 and billions of trees, but because of restrictions they can't be = harvested,=20 thinned, or put to good use, hence the pulp mills have = closed.
 
But, "where there is a will, there is a = way." =20 This Canned Water could be marketed.   I suggest we import the = necessary "seed waters" from Canada, in the same manner as we do for = natural gas=20 and oil products, or from Venezuela, or the Middle East.  I = did some=20 careful calculations and cost analyses.  We could process, can, and = market=20 the dehydrated water for about $4.15 per gallon for regular dehydrated, = and=20 $4.85 for the premium.
 
This has nothing to do with = earthquakes, so my=20 apologies for taking up space.
 
Ted
----- Original Message -----
From:=20 meredith lamb
Sent: Saturday, June 14, 2008 = 11:34=20 PM
Subject: Scientist water can=20 evaluation

I suppose every seismometry lab and kitchen, should = have one of=20 these......see:

http://seismom= eter.googlepages.com/scientistwater

(Just=20 follow the directions on the photo can label....simple = instructions...you too=20 can
figure it out I think...maybe....perhaps...sort = of...)

Think it=20 was made around the 1950's....wonder if its edible now...or=20 stale?

Probably a good old weight loss diet = perhaps...

The=20 "contents" are probably purer than todays ...

The weld lining = might=20 have some lead in the weld....bad for the brains....

Save it = for afew=20 thousand years, for at mo spheric evaluation?

Made in = California.....is=20 that really good?

I don't think it would make a good = seismometer=20 mass...the can is ferromagnetic.

Theres NO pull tab on = top....what do=20 we do now?

Can it you say?  Can the can?

Do we need = a=20 professional or learned evaluation?


Take care,  (Whats = his=20 name)




Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Sun, 15 Jun 2008 20:34:38 -0600 Hi Charles and all, Electronic Goldmine also has some INTRIGUING "unknown metal" bb's (ball bearings), of .190 & .250" diameters. #G15310 .190" diameter, 20 for $1. #G15311 .250" diameter, 15 for $1. Their description called them a unknown metal. If....their photographs are a accurate and undoctored representation; at least too me, they "look" alot like ~ polished carbide; mostly black with the photo flash small round reflection of light on the centered surface. I ordered some of the .250" variety..we'll find out eventually. The typical common silver gray chrome steel (majority) and the stainless steel varieties wouldn't normally look mostly black in a photo; but all things are possible. Anyway...it is better to get both the polished carbide drill/router shanks and (?) ball bearing at one place alot cheaper. Take care, Meredith On Fri, Jun 13, 2008 at 5:40 PM, Charles Patton wrote: > Another place to get carbide rods is: > http://www.goldmine-elec-products.com > They have individual carbide drill and router bits at $0.99 apiece. They > also pretty much always have a grab bag of bits. I just checked and item > no. G13259 is a bag of 8 or so bits for $2 -- a great deal. I've bought > these over the years from Goldmine to use in my Dremel tool. They're a great > bargain. When the Dremel HS steel burrs and router are used on steel, they > dull instantly, whereas the carbide bits keep on taking away metal. They're > the only bits I use. I tend to break them faster than I wear them out. > With regards to seismo pivots, the shanks are a consistent 1/8" size for > everything and the router bit were mirror polished in the last batch I > bought maybe six months ago so you might not even have to polish them. So > far as I can figure they're very good, micro-grain carbide bits that come > out of the circuit board industry. > > Anyway, just another thought. > Regards, > Charles Patton > > Hi Charles and all,

Electronic Goldmine also has some INTRIGUING "unknown metal" bb's (ball bearings), of .190 & .250" diameters.  #G15310 .190" diameter, 20 for $1.
#G15311 .250" diameter, 15 for $1.  Their description called them a unknown metal.  If....their photographs are a accurate and undoctored representation; at least
too me, they "look" alot like ~ polished carbide; mostly black with the photo flash small round reflection of light on the centered surface.  I ordered some of the .250"
variety..we'll find out eventually.  The typical common silver gray chrome steel (majority) and the stainless steel varieties wouldn't normally look mostly black in a photo;
but all things are possible.  Anyway...it is better to get both the polished carbide drill/router shanks and (?) ball bearing at one place alot cheaper.

Take care, Meredith

On Fri, Jun 13, 2008 at 5:40 PM, Charles Patton <charles.r.patton@........> wrote:
Another place to get carbide rods is:
http://www.goldmine-elec-products.com
They have individual carbide drill and router bits at $0.99 apiece. They also pretty much always have a grab bag of bits.  I just checked and item no. G13259 is a bag of 8 or so bits for $2 -- a great deal. I've bought these over the years from Goldmine to use in my Dremel tool. They're a great bargain.  When the Dremel HS steel burrs and router are used on steel, they dull instantly, whereas the carbide bits keep on taking away metal.  They're the only bits I use.  I tend to break them faster than I wear them out.  With regards to seismo pivots, the shanks are a consistent 1/8" size for everything and the router bit were mirror polished in the last batch I bought maybe six months ago  so you might not even have to polish them.  So far as I can figure they're very good, micro-grain carbide bits that come out of the circuit board industry.

Anyway, just another thought.
Regards,
Charles Patton


Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Sun, 15 Jun 2008 23:48:27 EDT In a message dated 2008/06/16, paleoartifact@......... writes: > Electronic Goldmine also has some INTRIGUING "unknown metal" bb's (ball > bearings), of .190 & .250" diameters. Hi Meredith, I suggest that you determine the density? Regards, Chris In a me= ssage dated 2008/06/16, paleoartifact@......... writes:

Electronic Goldmine also has so= me INTRIGUING "unknown metal" bb's (ball bearings), of .190 & .250" diam= eters.


Hi Meredith,

       I suggest that you determine the densit= y?

       Regards,

       Chris
Subject: RE: Tungsten Pins From: "Gary Lindgren" gel@................. Date: Mon, 16 Jun 2008 14:44:34 -0700 Hi Merdith, I just received my Tungsten Carbide 1/8" rods from Centennial Carbide. The surface finish is excellent and needs no further polishing. Not quite a mirror finish but very close. I got 10 rods and total cost was $17.30 including shipping. I would stay away from materials with 'unknown' description. How do you repeat a result. There plenty of sources at good prices for both rods and balls. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Sunday, June 15, 2008 7:35 PM To: psn-l@.............. Subject: Re: Tungsten Pins Hi Charles and all, Electronic Goldmine also has some INTRIGUING "unknown metal" bb's (ball bearings), of .190 & .250" diameters. #G15310 .190" diameter, 20 for $1. #G15311 .250" diameter, 15 for $1. Their description called them a unknown metal. If....their photographs are a accurate and undoctored representation; at least too me, they "look" alot like ~ polished carbide; mostly black with the photo flash small round reflection of light on the centered surface. I ordered some of the .250" variety..we'll find out eventually. The typical common silver gray chrome steel (majority) and the stainless steel varieties wouldn't normally look mostly black in a photo; but all things are possible. Anyway...it is better to get both the polished carbide drill/router shanks and (?) ball bearing at one place alot cheaper. Take care, Meredith On Fri, Jun 13, 2008 at 5:40 PM, Charles Patton wrote: Another place to get carbide rods is: http://www.goldmine-elec-products.com They have individual carbide drill and router bits at $0.99 apiece. They also pretty much always have a grab bag of bits. I just checked and item no. G13259 is a bag of 8 or so bits for $2 -- a great deal. I've bought these over the years from Goldmine to use in my Dremel tool. They're a great bargain. When the Dremel HS steel burrs and router are used on steel, they dull instantly, whereas the carbide bits keep on taking away metal. They're the only bits I use. I tend to break them faster than I wear them out. With regards to seismo pivots, the shanks are a consistent 1/8" size for everything and the router bit were mirror polished in the last batch I bought maybe six months ago so you might not even have to polish them. So far as I can figure they're very good, micro-grain carbide bits that come out of the circuit board industry. Anyway, just another thought. Regards, Charles Patton

Hi Merdith,

I just received my Tungsten Carbide 1/8” rods from Centennial Carbide. The surface finish is excellent and needs no further polishing. Not quite a mirror finish but very close. I got 10 rods and = total cost was $17.30 including shipping. I would stay away from materials with = ‘unknown’  description. How do you repeat a result. There plenty of sources = at good prices  for both rods and balls.

Gary   

 

 

 

 

 

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Sunday, June 15, 2008 7:35 PM
To: psn-l@..............
Subject: Re: Tungsten Pins

 

Hi Charles and = all,

Electronic Goldmine also has some INTRIGUING "unknown metal" = bb's (ball bearings), of .190 & .250" diameters.  #G15310 = ..190" diameter, 20 for $1.
#G15311 .250" diameter, 15 for $1.  Their description called = them a unknown metal.  If....their photographs are a accurate and = undoctored representation; at least
too me, they "look" alot like ~ polished carbide; mostly black = with the photo flash small round reflection of light on the centered = surface.  I ordered some of the .250"
variety..we'll find out eventually.  The typical common silver gray = chrome steel (majority) and the stainless steel varieties wouldn't normally = look mostly black in a photo;
but all things are possible.  Anyway...it is better to get both the polished carbide drill/router shanks and (?) ball bearing at one place = alot cheaper.

Take care, Meredith

On Fri, Jun 13, 2008 at 5:40 PM, Charles Patton = <charles.r.patton@........> wrote:

Another place to get carbide rods is:
http://www.goldmine-elec-products.com
They have individual carbide drill and router bits at $0.99 apiece. They = also pretty much always have a grab bag of bits.  I just checked and = item no. G13259 is a bag of 8 or so bits for $2 -- a great deal. I've bought = these over the years from Goldmine to use in my Dremel tool. They're a great = bargain.  When the Dremel HS steel burrs and router are used on steel, they = dull instantly, whereas the carbide bits keep on taking away metal. =  They're the only bits I use.  I tend to break them faster than I wear them = out.  With regards to seismo pivots, the shanks are a consistent = 1/8" size for everything and the router bit were mirror polished in the last batch = I bought maybe six months ago  so you might not even have to polish = them.  So far as I can figure they're very good, micro-grain carbide bits = that come out of the circuit board industry.

Anyway, just another thought.
Regards,
Charles Patton

 

 

Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Mon, 16 Jun 2008 17:14:56 -0600 Hi Chris, Unless they are a "exotic composition" ball; they probably won't take much more than a look to tell what they are of course. Take care, Meredith On Sun, Jun 15, 2008 at 9:48 PM, wrote: > In a message dated 2008/06/16, paleoartifact@......... writes: > > Electronic Goldmine also has some INTRIGUING "unknown metal" bb's (ball > bearings), of .190 & .250" diameters. > > > > Hi Meredith, > > I suggest that you determine the density? > > Regards, > > Chris Hi Chris,

Unless they are a "exotic composition" ball; they probably won't take much more than a look to tell what they are of course.

Take care, Meredith

On Sun, Jun 15, 2008 at 9:48 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/06/16, paleoartifact@......... writes:

Electronic Goldmine also has some INTRIGUING "unknown metal" bb's (ball bearings), of .190 & .250" diameters.


Hi Meredith,

       I suggest that you determine the density?

       Regards,

       Chris

Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Mon, 16 Jun 2008 17:59:45 -0600 Hi Gary, Very good on the rods! Your Centennial Carbide source will likely long outlast the surplus outlet supply route. In many ways....this "surface" aspect is hard to define to where its equitable scale is communicated across the broad spectrum....via some sort of everyday items that most people have; which they can use for comparison. Regardless; the smoother the rolling rods/ball pivot surfaces; the better the overall seismometer mass enertia results. Real bad intrigued curiosity = $1 = 15 ball surplus "lottery" = gamble. Take care, Meredith On Mon, Jun 16, 2008 at 3:44 PM, Gary Lindgren wrote: > Hi Merdith, > > I just received my Tungsten Carbide 1/8" rods from Centennial Carbide. The > surface finish is excellent and needs no further polishing. Not quite a > mirror finish but very close. I got 10 rods and total cost was $17.30 > including shipping. I would stay away from materials with 'unknown' > description. How do you repeat a result. There plenty of sources at good > prices for both rods and balls. > > Gary > > > > > > > > > > > > > Hi Gary,

Very good on the rods!   Your Centennial Carbide source will likely long outlast the surplus outlet supply route.

In many ways....this "surface" aspect is hard to define to where its equitable scale is communicated across the broad
spectrum....via some sort of everyday items that most people have; which they can use for comparison.  Regardless; the
smoother the rolling rods/ball pivot surfaces; the better the overall seismometer mass enertia results. 

Real bad intrigued curiosity = $1  = 15 ball surplus "lottery" = gamble.

Take care,  Meredith 

On Mon, Jun 16, 2008 at 3:44 PM, Gary Lindgren <gel@.................> wrote:

Hi Merdith,

I just received my Tungsten Carbide 1/8" rods from Centennial Carbide. The surface finish is excellent and needs no further polishing. Not quite a mirror finish but very close. I got 10 rods and total cost was $17.30 including shipping. I would stay away from materials with 'unknown'  description. How do you repeat a result. There plenty of sources at good prices  for both rods and balls.

Gary   

 

 

 

 

 

 


Subject: Re: How to download SAC binary files from IRIS From: Bobhelenmcclure@....... Date: Mon, 16 Jun 2008 22:48:56 EDT Sorry--I goofed by not checking out my directions for downloading IRIS files= . They must have revamped their site recently. Here are the revised=20 instructions: 1. Go to Wilber II http://www.iris.edu/cgi-bin/wilberII_page1.pl =20= =20 =20 2. Select List all events (upper right side) 3 Scroll down to event and click on it 4. Click on the network for the station you want, then click on Proceed at bottom of page 5. Unselect the stations you do not want =E2=80=93 Make sure the desired=20 station is selected. 6. On left side of page select BHE, BHN, and BHZ 7. Check SAC BINARY Individual Files on lower left !!!!! 8. Bottom middle =E2=80=93 check time before and after P Wave. However,=20 since you are requesting the SPYDER File, it will only be 60 minutes=20 long. You have to wait 60 to 90 days for the FARM file to get more=20 than 60 minutes. 9. Bottom right =E2=80=93 Enter a user name, and a request name (event name and date are good to use). Enter your name and email address, and don=E2= =80=99t=20 forget to check to be notified when the file is ready. You don't always get=20 an=20 email, so keep looking at the progress screen. It takes about 5 minutes at=20 most to get the files. You can download them to your computer. The URL=20 for your data will be:=20 ftp://ftp.iris.washington.edu/pub/userdata/[user name]/[request name]. Please use my utility "SAC_to_PSN" for conversion. I have modified=20 "SAC_to_PSN" to make velocity the default sensor type if not otherwise=20 specified in the SAC header. Also, select "Sensor Units" for "Y-Scale=20 Display Mode". Find my latest version of the utility at=20 http://bobmcclure90.googlepages.com/winsac WinQuake can load SAC files, and also do the conversion, but you will not=20 get=20 the sensor sensitivity number. My utility also transfers magnitude, but it i= s=20 never given=20 on the network files. If you use WinQuake to load and view SAC files, never= =20 try to=20 crop or downsample them. Save them as PSN files, and thereafter use the=20 PSN files for further processing.=20 My download, "winquake_utilities.zip", also includes "WQFilter.exe". I use= =20 it=20 exclusively to filter my WinQuake event files. I can convert my short period= =20 sensor data to something that resembles data from nearby PAL, which uses the STS-2 sensor. Cheers, Bob=20 ************** Gas prices getting you down? Search AOL Autos for=20 fuel-efficient used cars. (http://autos.aol.com/used?ncid=3Daolaut00050000000007) Sorry--I goofed by not checking out= my directions for downloading IRIS files.
They must have revamped their site recently. Here are the revised instructio= ns:

1.  Go to Wilber II        &nbs= p; http://www.iris.edu/cgi-bin/wilberII_page1.pl    &nbs= p;             <= BR> 2.  Select List all events (upper right side)
3   Scroll down to event and click on it
4.  Click on the network for the station you want, then click on Procee= d
at bottom of page
5.  Unselect the stations you do not want =E2=80=93 Make sure the desir= ed
station is selected.
6.  On left side of page select BHE, BHN, and BHZ
7.  Check SAC BINARY Individual Files on lower left !!!!!
8.  Bottom middle =E2=80=93 check time before and after P Wave.  H= owever,
since you are requesting the SPYDER File, it will only be 60 minutes
long. You have to wait 60 to 90 days for the FARM file to get more
than 60 minutes.
9.  Bottom right =E2=80=93 Enter a user name, and a request name (event= name
and date are good to use). Enter your name and email address, and don=E2= =80=99t
forget to check to be notified when the file is ready. You don't always get=20= an
email, so keep looking at the progress screen. It takes about 5 minutes at <= BR> most to get the files.  You can download them to your computer. The URL=
for your data will be:
ftp://ftp.iris.washington.edu/pub/userdata/[user name]/[request name].



  Please use my utility "SAC_to_PSN" for conversion. I have modified "SAC_to_PSN" to make velocity the default sensor type if not otherwise
specified in the SAC header. Also, select "Sensor Units" for "Y-Scale
Display Mode". Find my latest version of the utility at

http://bobmcclure90.googlepages.com/winsac

  WinQuake can load SAC files, and also do the conversion, but you will= not get
the sensor sensitivity number. My utility also transfers magnitude, but it i= s never given
on the network files.  If you use WinQuake to load and view SAC files,=20= never try to
crop or downsample them. Save them as PSN files, and thereafter use the
PSN files for further processing.

  My download, "winquake_utilities.zip", also includes "WQFilter.exe".=20= I use it
exclusively to filter my WinQuake event files. I can convert my short period= sensor
data to something that resembles data from nearby PAL, which uses the STS-2<= BR> sensor.

Cheers,

Bob



**************
Gas prices getting you down? Search= AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used= ?ncid=3Daolaut00050000000007) Subject: Re: Tungsten Pins From: "Dale Hardy" photon1@........... Date: Tue, 17 Jun 2008 12:57:29 +1000 Hi Meredith, omitted to mention those 'capstan' rods also have a 'domed' end which = has been used successfully as a pivot point on the arm of a lehman Dale
Hi Meredith,
omitted to mention those 'capstan' rods = also have a=20 'domed' end which has been used successfully as a pivot point on the arm = of a=20 lehman
Dale
Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Tue, 17 Jun 2008 09:41:47 -0600 Hi Dale, Good; at least you tried such. I do wish you had a real closeup camera and/or a web site to show the rounded end. My guess is that it is diamond wheel ground off and isn't anywhere near as round as a true sperical ball. Under ~ >15x magnifcation you visually might see "jerky steps" going up to the domed rods end point top. All those little steps likely significantly impede smooth rotation where they make contact; as compared to a much more finely rounded ball. This reminds years back of obtaining a unheat treated tool steel drill rod shank/blank. Boy, was that rod so visually shiny! Under magnification, the surface was so badly spirally groove marked from the lathe tool, it was completely unuseable in a cross rod pivot test, and yielded the shortest time for free oscillation time duration of any material I had. I "presume" your domed rod end is making contact on a flat surface. If you're game; just for fun, you might also sometime try a true crossed (3 rods) rod pivot on your (presumed) experimental "test" Lehman....it can work almost frictionless very well....but they do have a obvious tendency to "slip" or "walk" horizontally and vertically (or, at any angle); so you will probably have to have alotof setup patience with adjustments. All of which is why......the 2 rods and a ball is used; it totally eliminates all the otherwise pesky vertical slip/walk problem on a Lehman, but gets quite decent results. Take care, Meredith On Mon, Jun 16, 2008 at 8:57 PM, Dale Hardy wrote: > Hi Meredith, > omitted to mention those 'capstan' rods also have a 'domed' end which has > been used successfully as a pivot point on the arm of a lehman > Dale >
Hi Dale,
 
Good; at least you tried such.  I do wish you had a real closeup camera and/or a web site to show the rounded end.  My guess is that it is diamond
wheel ground off and isn't anywhere near as round as a true sperical ball.  Under ~ >15x magnifcation you visually might see "jerky steps" going
up to the domed rods end point top.  All those little steps likely significantly impede smooth rotation where they make contact; as compared to a
much more finely rounded ball.
 
This reminds years back of obtaining a unheat treated tool steel drill rod shank/blank.  Boy, was that rod so visually shiny!  Under magnification,
the surface was so badly spirally groove marked from the lathe tool, it was completely unuseable in a cross rod pivot test, and yielded the
shortest time for free oscillation time duration of any material I had.
 
I "presume" your domed rod end is making contact on a flat surface.
 
If you're game; just for fun, you might also sometime try a true crossed (3 rods) rod pivot on your (presumed) experimental "test" Lehman....it can
work almost frictionless very well....but they do have a obvious tendency to "slip" or "walk" horizontally and vertically (or, at any angle); so you will
probably have to have alotof setup patience with adjustments.  All of which is why......the 2 rods and a ball is used; it totally eliminates all the
otherwise pesky vertical slip/walk problem on a Lehman, but gets quite decent results.
 
Take care, Meredith 
 
 
 
    

On Mon, Jun 16, 2008 at 8:57 PM, Dale Hardy <photon1@...........> wrote:
Hi Meredith,
omitted to mention those 'capstan' rods also have a 'domed' end which has been used successfully as a pivot point on the arm of a lehman
Dale

Subject: Re: Scientist water can evaluation From: ChrisAtUpw@....... Date: Wed, 18 Jun 2008 00:04:41 EDT In a message dated 2008/06/15, tchannel1@............ writes: > Taking the water from the mountain to the north is out of the question > because of the adverse effects on the slopes of road construction and runoff into > the creeks and watershed, hence on the fish and wildlife. But being open > minded about it, an environmental feasibility study could be done. Hi Ted, A significant problem is the fast water runoff experienced in storm conditions. In the western US, you have problems with falling water table levels. If you could contour the land with earth banks, you could hold the water in place long enough for much of it to be absorbed into the soil. This can also dramatically improve crop yields. Contour ploughing can increase rain absorption. An airborne laser survey has been completed in the UK to identify areas which have increased risk. We have also had problems with flooding due to very heavy local rainfalls and are trying to learn from past problems. 'Extreme' weather conditions seem to be happening more often. Regards, Chris Chapman In a me= ssage dated 2008/06/15, tchannel1@............ writes:

Taking the water from the mount= ain to the north is out of the question because of the adverse effects on th= e slopes of road construction and runoff into the creeks and watershed, henc= e on the fish and wildlife.  But being open minded about it, an environ= mental feasibility study could be done.


Hi Ted,

       A significant problem is the fast water= runoff experienced in storm conditions. In the western US, you have problem= s with falling water table levels. If you could contour the land with earth=20= banks, you could hold the water in place long enough for much of it to be ab= sorbed into the soil. This can also dramatically improve crop yields. Contou= r ploughing can increase rain absorption.

       An airborne laser survey has been compl= eted in the UK to identify areas which have increased risk. We have also had= problems with flooding due to very heavy local rainfalls and are trying to=20= learn from past problems. 'Extreme' weather conditions seem to be happening=20= more often.

       Regards,

       Chris Chapman
Subject: Re: Tungsten Pins From: "Dale Hardy" photon1@........... Date: Wed, 18 Jun 2008 16:09:27 +1000 Hi Meredith, best picture i can take is at http://www.daleh.id.au/pictures1.html that is about 12X Under 10X glass no sign of grinding marks, the reflection in the image = is my window near where i took the picture. 3 Rods ? as in >|o|< arrangement ? ta Dale ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Wednesday, June 18, 2008 1:41 AM Subject: Re: Tungsten Pins Hi Dale, Good; at least you tried such. I do wish you had a real closeup = camera and/or a web site to show the rounded end. My guess is that it = is diamond wheel ground off and isn't anywhere near as round as a true sperical = ball. Under ~ >15x magnifcation you visually might see "jerky steps" = going up to the domed rods end point top. All those little steps likely = significantly impede smooth rotation where they make contact; as = compared to a much more finely rounded ball. This reminds years back of obtaining a unheat treated tool steel drill = rod shank/blank. Boy, was that rod so visually shiny! Under = magnification, the surface was so badly spirally groove marked from the lathe tool, = it was completely unuseable in a cross rod pivot test, and yielded the shortest time for free oscillation time duration of any material I = had. I "presume" your domed rod end is making contact on a flat surface. If you're game; just for fun, you might also sometime try a true = crossed (3 rods) rod pivot on your (presumed) experimental "test" = Lehman....it can work almost frictionless very well....but they do have a obvious = tendency to "slip" or "walk" horizontally and vertically (or, at any = angle); so you will probably have to have alotof setup patience with adjustments. All of = which is why......the 2 rods and a ball is used; it totally eliminates = all the=20 otherwise pesky vertical slip/walk problem on a Lehman, but gets quite = decent results. Take care, Meredith=20 =20 On Mon, Jun 16, 2008 at 8:57 PM, Dale Hardy = wrote: Hi Meredith, omitted to mention those 'capstan' rods also have a 'domed' end = which has been used successfully as a pivot point on the arm of a lehman Dale -------------------------------------------------------------------------= ----- Internal Virus Database is out-of-date. Checked by AVG.=20 Version: 7.5.524 / Virus Database: 269.24.6 - Release Date: 3/06/2008 = 12:00 AM
Hi Meredith,
best picture i can take is at http://www.daleh.id.au/pic= tures1.html
 that is about 12X
Under 10X glass no sign of grinding = marks, the=20 reflection in the image is my window near where i took the = picture.
3 Rods ? as in >|o|< arrangement=20 ?
ta
Dale
----- Original Message -----
From:=20 meredith lamb
Sent: Wednesday, June 18, 2008 = 1:41=20 AM
Subject: Re: Tungsten = Pins

Hi Dale,
 
Good; at least you tried such.  I do wish you had a real = closeup=20 camera and/or a web site to show the rounded end.  My guess = is that=20 it is diamond
wheel ground off and isn't anywhere near as round as a true = sperical=20 ball.  Under ~ >15x magnifcation you visually might see = "jerky=20 steps" going
up to the domed rods end point top.  All those little steps = likely=20 significantly impede smooth rotation where they make contact; as = compared to=20 a
much more finely rounded ball.
 
This reminds years back of obtaining a unheat treated tool = steel=20 drill rod shank/blank.  Boy, was that rod so visually = shiny!  Under=20 magnification,
the surface was so badly spirally groove marked from the = lathe tool,=20 it was completely unuseable in a cross rod pivot test, and = yielded=20 the
shortest time for free oscillation time duration of any material = I=20 had.
 
I "presume" your domed rod end is making contact on a flat=20 surface.
 
If you're game; just for fun, you might also sometime try a = true=20 crossed (3 rods) rod pivot on your (presumed) experimental "test"=20 Lehman....it can
work almost frictionless very = well....but they=20 do have a obvious tendency to "slip" or "walk" horizontally and = vertically=20 (or, at any angle); so you will
probably have to have alotof setup = patience=20 with adjustments.  All of which is why......the 2 rods and a ball = is=20 used; it totally eliminates all the
otherwise pesky vertical=20 slip/walk problem on a Lehman, but gets quite decent results.
 
Take care, Meredith 
 
 
 
    

On Mon, Jun 16, 2008 at 8:57 PM, Dale Hardy = <photon1@...........>=20 wrote:
Hi Meredith,
omitted to mention those 'capstan' = rods also=20 have a 'domed' end which has been used successfully as a pivot point = on the=20 arm of a lehman
Dale


Internal Virus Database is out-of-date.
Checked by AVG. =
Version:=20 7.5.524 / Virus Database: 269.24.6 - Release Date: 3/06/2008 12:00=20 AM
Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Wed, 18 Jun 2008 04:05:52 EDT In a message dated 2008/06/18, photon1@........... writes: > Hi Meredith, > best picture I can take is at http://www.daleh.id.au/pictures1.html > that is about 12X Under 10X glass no sign of grinding marks, the reflection > in the image is my window near where I took the picture. > 3 Rods ? as in >|o|< arrangement ? > Dale Hi Meredith / Dale, The cheapest suspension which seems to work well is a 3/8" to 1/2" Stainless Steel Ball Bearing rolling on strip of SS cut from a Skin Graft Scalpel Blade. The blades are 2" long, 5/16" wide and 0.016" thick. You can cut five strips from each blade with a carbide disk quite easily and they cost about $1. I stick them to the end of the arm with two part acrylic adhesive eg Devcon 'Plastic Welder' S-220 22045. I haven't had any problems with the suspension wandering. I prefer to use just two crossed rollers with a Lehman suspension. If you are building a vertical, you can use two vertical rollers on the upright and a horizontal roller on the end of the arm. Regards, Chris Chapman In a me= ssage dated 2008/06/18, photon1@........... writes:

Hi Meredith,
best picture I can take is at http://www.daleh.id.au/pictures1.html
that is about 12X Under 10X glass no sign of grinding marks, the reflectio= n in the image is my window near where I took the picture.
3 Rods ? as in >|o|< arrangement ?
Dale


Hi Meredith / Dale,

       The cheapest suspension which seems to=20= work well is a 3/8" to 1/2" Stainless Steel Ball Bearing rolling on strip of= SS cut from a Skin Graft Scalpel Blade. The blades are 2" long, 5/16" wide=20= and 0.016" thick. You can cut five strips from each blade with a carbide dis= k quite easily and they cost about $1. I stick them to the end of the arm wi= th two part acrylic adhesive eg Devcon 'Plastic Welder' S-220 22045. I haven= 't had any problems with the suspension wandering.

       I prefer to use just two crossed roller= s with a Lehman suspension. If you are building a vertical, you can use two=20= vertical rollers on the upright and a horizontal roller on the end of the ar= m.

       Regards,

       Chris Chapman
Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Wed, 18 Jun 2008 10:51:04 -0600 Hi Dale, You have spectacular nature/science images on your website! Very good result image enlarging effort with what you had...thanks! Although the 2 photos are angled, I see the rod was single cut/pass diamond wheel 45 degree chamfered around the outer top ends. Then it was diamond tumbled polished. The end point was initially flat after chamfer and any rounding polished action could have potentially made a slight bit of centered ~ rounded point thereon. The outer diameter rod itself looks to have a adequate rolling pivot contact surface finish. As for myself....I think I'd rather use a more spherical ball pivot point. Take care, Meredith On Wed, Jun 18, 2008 at 12:09 AM, Dale Hardy wrote: > Hi Meredith, > best picture i can take is at http://www.daleh.id.au/pictures1.html > that is about 12X > Under 10X glass no sign of grinding marks, the reflection in the image is > my window near where i took the picture. > 3 Rods ? as in >|o|< arrangement ? > ta > Dale > > > >
Hi Dale,
 
You have spectacular nature/science images on your website!
 
Very good result image enlarging effort with what you had...thanks!
 
Although the 2 photos are angled, I see the rod was single cut/pass diamond wheel 45 degree chamfered around the outer top ends.
Then it was diamond tumbled polished.  The end point was initially flat after chamfer and any rounding polished
action could have potentially made a slight bit of centered ~ rounded point thereon.  The outer diameter rod itself looks to have a
adequate rolling pivot contact surface finish.  As for myself....I think I'd rather use a more spherical ball pivot point.
 
Take care, Meredith


 
On Wed, Jun 18, 2008 at 12:09 AM, Dale Hardy <photon1@...........> wrote:
Hi Meredith,
best picture i can take is at http://www.daleh.id.au/pictures1.html
 that is about 12X
Under 10X glass no sign of grinding marks, the reflection in the image is my window near where i took the picture.
3 Rods ? as in >|o|< arrangement ?
ta
Dale
 
Subject: Alnico magnets as a pivot surface From: "meredith lamb" paleoartifact@......... Date: Wed, 18 Jun 2008 12:24:36 -0600 Hi all, Yes.....another potential pivot. Not totally new at all, but quite interesting for its possible wide range of flat alnico surface and the round steel/carbide pivot ball use in a S-G, Lehman or vertical seismometer/s. http://seismometer.googlepages.com/alnico Take care, Meredith
Hi all,
 
Yes.....another potential pivot.  Not totally new at all, but quite interesting for its possible wide range of
flat alnico surface and the round steel/carbide pivot ball use in a S-G, Lehman or vertical seismometer/s.
 
 
Take care, Meredith
 
 
Subject: A S-G magnetic ball to ball point pivot From: "meredith lamb" paleoartifact@......... Date: Wed, 18 Jun 2008 17:20:21 -0600 Hi all, The alnico web page reminds me of another pivot, where although I don't presently have a web page to illustrate it; I think I can text describe such. Its been covered somewhat before; but that variety used crossed neodymium rods... which were certainly terrible for a pivot surface. Even that arrangement ended up supporting a 2 pound mass. Too much mass and of course the boom/mass falls off/down. Assuming you want a S-G pivot which is a vertical hanging mass. One could mount a flat strong neodymium magnet at the top of the frame. Mount and glue down two spaced steel or carbide balls on such. On the boom facing the balls mount/glue two more steel/carbide balls with the same spacing. Mount the mass on the boom. Click them together. Thats it! Simple magnetics and gravity force the pivot to remain in their fixed points. Take care, Meredith
Hi all,
 
The alnico web page reminds me of another pivot, where although I don't presently have a web page to illustrate it; I think
I can text describe such.  Its been covered somewhat before; but that variety used crossed neodymium rods...
which were certainly terrible for a pivot surface.  Even that arrangement ended up supporting a 2 pound mass.
Too much mass and of course the boom/mass falls off/down.
 
Assuming you want a S-G pivot which is a vertical hanging mass.  One could mount a flat strong neodymium magnet at the
top of the frame.   Mount and glue down two spaced steel or carbide balls on such.  On the boom facing the
balls mount/glue two more steel/carbide balls with the same spacing.  Mount the mass on the boom. Click them together.
Thats it!  Simple magnetics and gravity force the pivot to remain in their fixed points. 
 
Take care, Meredith
 
 
Subject: Four magnetic steel balls for a S-G pivot From: "meredith lamb" paleoartifact@......... Date: Thu, 19 Jun 2008 19:49:13 -0600 Hi all, I "whomped" up a experimental fixed magnetic steel ball bearing/s pivot just today, and it seems to work fairly well already. Their is peculiar features of the pivot that are kind of unique to a magnetic model, but they all improve or disappear altogether by simply adding mass weight! The web page below begins with the construction of the pivot itself, and then proceeds to initial results. See: http://seismometer.googlepages.com/mbonb Take care, Meredith
Hi all,
 
I "whomped" up a experimental fixed magnetic steel ball bearing/s pivot just today, and it seems to work fairly
well already.  
  
Their is peculiar features of the pivot that are kind of unique to a magnetic model, but they all
improve or disappear altogether by simply adding mass weight! 
 
The web page below begins with the construction of the pivot itself, and then proceeds to initial results.
See:
 
 
Take care, Meredith
 
 
Subject: Newbie trying to get started From: Steinar Midtskogen steinar@............. Date: Fri, 20 Jun 2008 22:07:01 +0200 Hello List, I'm in the process of setting up a seismometer. I was considering a few options for building one based on internet descriptions, until I found the SEP seismometer which at £315 seemed likely to turn out cheaper than all parts needed to build one myself: http://www.mutr.co.uk/product_info.php?products_id=9047 So I got this seismometer and a quick start. I built a box for it, and I set up a datalogger. For the datalogger I'm using a Linksys NSLU2 which is running SlugOS Linux. It's a little box with a 266MHz ARM processor and 32 MB RAM, plenty for the task. It has ethernet and two USB ports. I've plugged a card reader into one port, to which I've connected two flash cards which makes up the filesystem configured as RAID 1 for added reliability, and the other is used to connect to the seismometer by a serial cable. So far, so good. Now I only need to add some software. I've searched a bit for existing software, but it turns out to be mostly Windows or DOS applications with no source code provided, which wont run on an ARM processor. I think that to use a full blown leftover pc running Windows for the task is both impractical and expensive. I guess I have to write some code myself. I wrote a small program which logs the data from the seismometer. I currently plot what I get on this web page (using gnuplot): http://voksenlia.net/met/seismometer/ What's remaining is some processing prior to plotting. I most likely need to process my data with a lowpass filter. But then I've run into a problem. I know very little about signal processing, and I don't know what type of filter I should use for the best results. Existing software uses filters it seems, but I haven't found any source code which could help me out. So I turn to this list. I have a 16 bit A/D converter sampling at 20 Hz. My seismometer has a natural period of about 16 seconds. How should I process the data? -- Steinar ; NIL DIFFICILE VOLENTI ; http://latinitas.org ; http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Newbie trying to get started From: ChrisAtUpw@....... Date: Fri, 20 Jun 2008 18:02:27 EDT In a message dated 2008/06/20, steinar@............. writes: > Hello List, > I'm in the process of setting up a seismometer. I was considering a > few options for building one based on internet descriptions, until I > found the SEP seismometer which at =A3315 seemed likely to turn out > cheaper than all parts needed to build one myself:=20 >=20 > http://www.mutr.co.uk/product_info.php?products_id=3D9047 >=20 > So I got this seismometer and a quick start. I built a box for it, > and I set up a datalogger. For the datalogger I'm using a Linksys > NSLU2 which is running SlugOS Linux. It's a little box with a 266MHz > ARM processor and 32 MB RAM, plenty for the task. It has ethernet and > two USB ports. I've plugged a card reader into one port, to which > I've connected two flash cards which makes up the filesystem > configured as RAID 1 for added reliability, and the other is used to > connect to the seismometer by a serial cable. >=20 > So far, so good. Now I only need to add some software. I've searched > a bit for existing software, but it turns out to be mostly Windows or > DOS applications with no source code provided, which wont run on an > ARM processor. I think that to use a full blown leftover pc running > Windows for the task is both impractical and expensive. I guess I > have to write some code myself. >=20 > I wrote a small program which logs the data from the seismometer. I > currently plot what I get on this web page (using gnuplot): >=20 > http://voksenlia.net/met/seismometer/ >=20 > What's remaining is some processing prior to plotting. I most likely > need to process my data with a lowpass filter. But then I've run into > a problem. I know very little about signal processing, and I don't > know what type of filter I should use for the best results. Existing > software uses filters it seems, but I haven't found any source code > which could help me out. So I turn to this list. >=20 > I have a 16 bit A/D converter sampling at 20 Hz. My seismometer has a > natural period of about 16 seconds. How should I process the data? Hi Steinar, You seem to be trying to do things the hard way! The SEP box is designed to plug directly into almost any old PC=20 running windows! You download the AmaSeis data logging and analysis software= from=20 http://bingweb.binghamton.edu/~ajones/AmaSeis.html This gives you a WHOLE SU= ITE=20 of dedicated seismic programs, including both low and high pass digital=20 filters, FFT analysis and a lot more! The hard work has already been done fo= r you! It also contains the control program for the SEP ADC, which you have=20 to select on setup. It also supplies both screen and analysis display filter= s.=20 The amplifier has an inbuilt low pass filter at 5 Hz, but it will handle=20 periods out to over 30 seconds. A lot of the surface Love waves peak at peri= ods of=20 about 20 seconds. I can set the seismometer period to 20 seconds without any= =20 problem. You may find it beneficial to run the drumplot screen display low pas= s=20 filter set at about 10 seconds. This cuts out the ocean microseism backgroun= d=20 at about 6 seconds and makes most quakes easily recognisable. You can then=20 extract a trace and analyse if for the P and S waves. If you input your own=20 station location at setup and know the initial earthquake time, you can disp= lay=20 travel time curves on the analysis screen and match the two up! Regards, Chris Chapman =20 In a me= ssage dated 2008/06/20, steinar@............. writes:

Hello List,
I'm in the process of setting up a seismometer.  I was considering a few options for building one based on internet descriptions, until I
found the SEP seismometer which at =A3315 seemed likely to turn out
cheaper than all parts needed to build one myself:

http://www.mutr.co.uk/product_info.php?products_id=3D9047

So I got this seismometer and a quick start.  I built a box for it,
and I set up a datalogger.  For the datalogger I'm using a Linksys
NSLU2 which is running SlugOS Linux.  It's a little box with a 266MHz ARM processor and 32 MB RAM, plenty for the task.  It has ethernet and<= BR> two USB ports.  I've plugged a card reader into one port, to which
I've connected two flash cards which makes up the filesystem
configured as RAID 1 for added reliability, and the other is used to
connect to the seismometer by a serial cable.

So far, so good.  Now I only need to add some software.  I've sear= ched
a bit for existing software, but it turns out to be mostly Windows or
DOS applications with no source code provided, which wont run on an
ARM processor.  I think that to use a full blown leftover pc running Windows for the task is both impractical and expensive.  I guess I
have to write some code myself.

I wrote a small program which logs the data from the seismometer.  I currently plot what I get on this web page (using gnuplot):

http://voksenlia.net/met/seismometer/

What's remaining is some processing prior to plotting.  I most likely need to process my data with a lowpass filter.  But then I've run into<= BR> a problem.  I know very little about signal processing, and I don't
know what type of filter I should use for the best results.  Existing software uses filters it seems, but I haven't found any source code
which could help me out.  So I turn to this list.

I have a 16 bit A/D converter sampling at 20 Hz.  My seismometer has a<= BR> natural period of about 16 seconds.  How should I process the data?

Hi Steinar,

       You seem to be trying to do things the=20= hard way!

       The SEP box is designed to plug directl= y into almost any old PC running windows! You download the AmaSeis data logg= ing and analysis software from http://bingweb.binghamton.edu/~ajones/AmaSeis= ..html This gives you a WHOLE SUITE of dedicated seismic programs, including=20= both low and high pass digital filters, FFT analysis and a lot more! The har= d work has already been done for you!

       It also contains the control program fo= r the SEP ADC, which you have to select on setup. It also supplies both scre= en and analysis display filters. The amplifier has an inbuilt low pass filte= r at 5 Hz, but it will handle periods out to over 30 seconds. A lot of the s= urface Love waves peak at periods of about 20 seconds. I can set the seismom= eter period to 20 seconds without any problem.

       You may find it beneficial to run the d= rumplot screen display low pass filter set at about 10 seconds. This cuts ou= t the ocean microseism background at about 6 seconds and makes most quakes e= asily recognisable. You can then extract a trace and analyse if for the P an= d S waves. If you input your own station location at setup and know the init= ial earthquake time, you can display travel time curves on the analysis scre= en and match the two up!

       Regards,

       Chris Chapman
Subject: Re: Newbie trying to get started From: John Lahr johnjan@........ Date: Fri, 20 Jun 2008 17:41:32 -0700 I second Chris' suggestion to use the free AmaSeis PC software. For school seismic systems I've purchased used Win98SE computers for about $50. If you value your programming time at all, you'll come out way ahead. With Internet access the PC clock can be kept within a few seconds of true time using free software, which makes analysis much easier. On the other hand, there may well be some Linux logging software "out there" that you could start with. I just set up a SEP seismic system and agree that the price is hard to beat and the design is quite good. Cheers, John #################################/ John C. Lahr ################################/ Emeritus Seismologist ###############################/ U.S. Geological Survey ==========================/ Central Region Geologic Hazards Team #############################//################################# ############################//################################## PO Box 548 /################################### Corvallis, Oregon 97339 /=============================== Phone: (541) 758-2699 /#################################### Cell: (541) 740-4844 /##################################### Fax: (413) 658-2699 /###################################### johnjan@........ /####################################### http://jclahr.com/science/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Newbie trying to get started From: ChrisAtUpw@....... Date: Fri, 20 Jun 2008 20:58:32 EDT In a message dated 2008/06/20, steinar@............. writes: > Now I only need to add some software. I've searched a bit for existing > software, but it turns out to be mostly Windows or DOS applications with no > source code provided, which won't run on an ARM processor. Hi Steinar, There used to be a program for simulating / running Windows on ARM processors. They would run windows faster than the series 4 Intel processor chips!! ` Regards, Chris Chapman In a me= ssage dated 2008/06/20, steinar@............. writes:

Now I only need to add some sof= tware.  I've searched a bit for existing software, but it turns out to=20= be mostly Windows or DOS applications with no source code provided, which wo= n't run on an ARM processor.


Hi Steinar,

       There used to be a program for simulati= ng / running Windows on ARM processors. They would run windows faster than t= he series 4 Intel processor chips!!

`      Regards,

       Chris Chapman
Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Fri, 20 Jun 2008 22:14:26 -0600 Hi Chris and all, I think I can now mentally see the very likelyhood of increased friction with two rods and a ball over that of the true 3 crossed rods pivot. Being as the ball is set tightly in a straight linear "groove" (inbetween the two rods), and the horizontal pendulum/boom/pivot ball swings in a slight up-down arc there would logically be some ball arching response rotational rubbing friction of the ball on the two rods trying to accomodate this motion of the boom/mass. Of course; if there was a straight linear motion of the pivot/boom/mass in strict alignment with the two rods and the ball pivot, the ball would simply rotate in a happier more frictionless harmony. Judging from all this rotaton arching nature of the traditonal Lehman; I think it would logically be much better to switch too, or use, the 3 crossed rod pivot. By itself the 3 crossed rod pivot is indeed a excellent choice for a pivot with its ultra-low frictional loss. This is only my choice; but I've not tried them all. Of course there is other pivots used in a Lehman which the builder has a choice of using. Conjecture on the "best" of these will likely go on a long time. Perhaps to ease this gap; it could be possible to have the PSN members simply do a undampened time duration of their announced variety of seismometer pivot, by say a set amount of offset (~ like 1/16" one side of the mass), and simply denote the amount of time till the oscillations obviously disappear on the traces from the normal background noise...this is simply a indication of friction in the pivot. Over time, the "best" pivot variety would likely become more obvious. I've mentioned it before; but I'll mention it again...The Sprengnether "offset wire" pivot they used back in the 1950's, for their horizontal seismometers has been rather a "lost" use pivot. It falls in the torsion aspect as the music wire slightly bends with boom/mass rotation. Theres NO rods, steel/carbide balls or mirror surface etc., required. Probably the best visual basic understanding demonstration of it is in John Lahrs website; specifically for the solid ring and wire shown. If build rigidly, they can literally last "forever". Personally I've never seen one break. The science of these isn't set in stone; so individual experimentation comes into play....which can be fun to do. http://www.jclahr.com/science/psn/gate.html http://www.jclahr.com/science/psn/cor_psn.html Take care, Meredith Lamb On Wed, Jun 18, 2008 at 6:39 PM, wrote: > I would like to see a run down pendulum test on this to check it. > Regards, > > Chris
Hi Chris and all,
 
I think I can now mentally see the very likelyhood of increased friction with two rods and a ball over that of the
true 3 crossed rods pivot.  Being as the ball is set tightly in a straight linear "groove" (inbetween the two rods), and
the horizontal pendulum/boom/pivot ball swings in a slight up-down arc there would logically be some ball
arching response rotational rubbing friction of the ball on the two rods trying to accomodate this motion of the
boom/mass.
 
Of course; if there was a straight linear motion of the pivot/boom/mass in strict alignment with the two rods
and the ball pivot, the ball would simply rotate in a happier more frictionless harmony.
 
Judging from all this rotaton arching nature of the traditonal Lehman; I think it would logically be much better to
switch too, or use, the 3 crossed rod pivot.  By itself the 3 crossed rod pivot is indeed a excellent choice for
a pivot with its ultra-low frictional loss.  This is only my choice; but I've not tried them all.
 
Of course there is other pivots used in a Lehman which the builder has a choice of using.  Conjecture on the
"best" of these will likely go on a long time.  Perhaps to ease this gap; it could be possible to have the PSN
members simply do a undampened time duration of their announced variety of seismometer pivot, by say a set amount
of offset (~ like 1/16" one side of the mass), and simply denote the amount of time till the oscillations obviously
disappear on the traces from the normal background noise...this is simply a indication of friction in the pivot.  Over time,
the "best" pivot variety would likely become more obvious.
 
I've mentioned it before; but I'll mention it again...The Sprengnether "offset wire" pivot they used back in the 1950's,
for their horizontal seismometers has been rather a "lost" use pivot.  It falls in the torsion aspect as the music wire
slightly bends with boom/mass rotation.  Theres NO rods, steel/carbide balls or mirror surface etc., required.  Probably
the best visual basic understanding demonstration of it is in John Lahrs website; specifically for the solid ring and
wire shown.  If build rigidly, they can literally last "forever".   Personally I've never seen one break.  The science of
these isn't set in stone; so individual experimentation comes into play....which can be fun to do.
 
 
Take care, Meredith Lamb

 
On Wed, Jun 18, 2008 at 6:39 PM, <ChrisAtUpw@.......> wrote:
       I would like to see a run down pendulum test on this to check it. 
 
       Regards,

       Chris

Subject: Re: Newbie trying to get started From: Steinar Midtskogen steinar@............. Date: Sat, 21 Jun 2008 09:06:47 +0200 [ChrisAtUpw@........ > You seem to be trying to do things the hard way! It is also a good way to learn how things work, so I'm willing to make a try. > The SEP box is designed to plug directly into almost any old > PC running windows! You download the AmaSeis data logging and > analysis software from http: > //bingweb.binghamton.edu/~ajones/AmaSeis.html This gives you a WHOLE > SUITE of dedicated seismic programs, including both low and high > pass digital filters, FFT analysis and a lot more! The hard work has > already been done for you! I guess, but it is the x86 Windows part which is my problem. True, I can probably get a 20 year old Windows PC for free somewhere, though it will still add to the electricity bill (wouldn't a PC with moving parts, i.e. harddisk and fans, nearby the seismometer cause some vibrations?) and it would take up even more space in the basement storeroom (where I have the seismometer) which I don't really have. My real concern is probably that I don't like to run software which I'm unable to modify to my needs. No source code = no control. Anyway, the piece of code for reading the data was trivial, just a few lines of C code. And gnuplot does the plotting job for me, at least the plotting that can be done automatically for a web page. All this was done in a few hours. So I think the only thing I'm missing is the filter. Does any seismic programs come with source code? But I'll have a look at AmaSeis anyway, which might be useful for manual analysis of seismic events. If I make my logger program store raw data in a way AmaSeis can read it, I don't need to run AmaSeis on my datalogger. My regular PC is an AMD64 running Linux, but chances that AmaSeis will run on it using Wine should be good. I did make a very simple filter: output[i] = output[i-1] + alpha * (input[i] - output[i-1]); and experimented with different values for alpha, but I suspect that this filter is too soft. -- Steinar ; NIL DIFFICILE VOLENTI ; http://latinitas.org ; http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Newbie trying to get started From: Mark Robinson mark.robinson@............... Date: Sat, 21 Jun 2008 20:03:56 +1200 Steinar Midtskogen wrote: > [ChrisAtUpw@........ > >> You seem to be trying to do things the hard way! > > It is also a good way to learn how things work, so I'm willing to make > a try. > >> The SEP box is designed to plug directly into almost any old >> PC running windows! You download the AmaSeis data logging and >> analysis software from http: >> //bingweb.binghamton.edu/~ajones/AmaSeis.html This gives you a WHOLE >> SUITE of dedicated seismic programs, including both low and high >> pass digital filters, FFT analysis and a lot more! The hard work has >> already been done for you! > > I guess, but it is the x86 Windows part which is my problem. True, I > can probably get a 20 year old Windows PC for free somewhere, though > it will still add to the electricity bill (wouldn't a PC with moving > parts, i.e. harddisk and fans, nearby the seismometer cause some > vibrations?) and it would take up even more space in the basement > storeroom (where I have the seismometer) which I don't really have. > > My real concern is probably that I don't like to run software which > I'm unable to modify to my needs. No source code = no control. > > Anyway, the piece of code for reading the data was trivial, just a few > lines of C code. And gnuplot does the plotting job for me, at least > the plotting that can be done automatically for a web page. All this > was done in a few hours. > > So I think the only thing I'm missing is the filter. Does any seismic > programs come with source code? > > But I'll have a look at AmaSeis anyway, which might be useful for > manual analysis of seismic events. If I make my logger program store > raw data in a way AmaSeis can read it, I don't need to run AmaSeis on > my datalogger. My regular PC is an AMD64 running Linux, but chances > that AmaSeis will run on it using Wine should be good. > > > I did make a very simple filter: > > output[i] = output[i-1] + alpha * (input[i] - output[i-1]); > > and experimented with different values for alpha, but I suspect that > this filter is too soft. This looks like an ideal use for a slug to me. Perhaps you could simply average every ten readings as a low pass filter. It would also be easy to make the raw data stream available on a port to any external application which can then do further processing. Can Amaseis swallow such a stream ? Nice work. -- Mark ------------- 21 Jun 1990 50,000 people die as the result of an earthquake in Iran. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Newbie trying to get started From: ian ian@........... Date: Sat, 21 Jun 2008 09:08:40 +0100 H, I'm running what might be considered to be the worst case scenario, 2 pc's 1 windows box and 1 linux. I have a National Instruments A/D and I couldn't be bothered installing the open source linux drivers, windows drivers are part of the standard labview install and it all works "right out of the box". The machine runs windows 2000 and hasn't been rebooted for over a year nor has it crashed. It's a 800 MHz pentium. Everything is on a UPS. From there, the linux box (1 GHz pentium) makes a tcp socket connection to the windows box and "sucks" the time stamped data. It then uses pgplot to graph and x screen grabs to keep the website updated. All done from C and csh scripts. One day I'll do something sensible and merge the 2 halves into 1 machine. I'd recommend a hardware filter. If you do it in software you need a fast processor and you need to up the sampling rate of the A/D. Larry Cochrane sells filter boards through the psn website and they are pretty mainstream in the community. I have a couple of dual channel Krohn Hite 3322 programmable filters. One is next to the sensor and set up as the high pass filter and the other, 100ft away, set up as the low pass filter (to filter computer noise etc) Cheers Ian Steinar Midtskogen wrote: > [ChrisAtUpw@........ > > >> You seem to be trying to do things the hard way! >> > > It is also a good way to learn how things work, so I'm willing to make > a try. > > >> The SEP box is designed to plug directly into almost any old >> PC running windows! You download the AmaSeis data logging and >> analysis software from http: >> //bingweb.binghamton.edu/~ajones/AmaSeis.html This gives you a WHOLE >> SUITE of dedicated seismic programs, including both low and high >> pass digital filters, FFT analysis and a lot more! The hard work has >> already been done for you! >> > > I guess, but it is the x86 Windows part which is my problem. True, I > can probably get a 20 year old Windows PC for free somewhere, though > it will still add to the electricity bill (wouldn't a PC with moving > parts, i.e. harddisk and fans, nearby the seismometer cause some > vibrations?) and it would take up even more space in the basement > storeroom (where I have the seismometer) which I don't really have. > > My real concern is probably that I don't like to run software which > I'm unable to modify to my needs. No source code = no control. > > Anyway, the piece of code for reading the data was trivial, just a few > lines of C code. And gnuplot does the plotting job for me, at least > the plotting that can be done automatically for a web page. All this > was done in a few hours. > > So I think the only thing I'm missing is the filter. Does any seismic > programs come with source code? > > But I'll have a look at AmaSeis anyway, which might be useful for > manual analysis of seismic events. If I make my logger program store > raw data in a way AmaSeis can read it, I don't need to run AmaSeis on > my datalogger. My regular PC is an AMD64 running Linux, but chances > that AmaSeis will run on it using Wine should be good. > > > I did make a very simple filter: > > output[i] = output[i-1] + alpha * (input[i] - output[i-1]); > > and experimented with different values for alpha, but I suspect that > this filter is too soft. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re:Newbie trying to get started From: rsparks rsparks@.......... Date: Sat, 21 Jun 2008 08:15:41 -0700 Congratulations on writing your own recording software. Judging from your posted recordings, your software is performing well. Software filters can enhance the recording but certainly are not necessary. They can help dramatically to spot weak local quakes that have a high frequency signature, up to about 10 hz. I frequently see these small quakes "riding" on the much stronger microseims caused by the ocean waves which have a frequency in the 0.2 hz range. A high pass filter reduces the microseims leaving the quake much more visible. On the other hand, a low pass filter can do a lot to reduce the local environmental noise which tends to be high frequency. Too much LP filtering will hide any small local quakes that might occur. I have some code written in C++ but it was written a couple of years ago and it would take some time to tease it into something I could share and would be understandable to you. Briefly, an Infinite impulse response (IIR) filter is one of the easiest to use and implement. If you google "iir filter" you will get a multitude of references, many of which have detailed mathematical explanations. On the other hand, if you simply think of a filter as being an averaging device that takes samples and either finds the long term average (a low pass filter) or the short term difference (a high pass filter), you can make a surprisingly effective software filter very quickly. Use the formula y[n] = c0*x[n] + c1*x[n-1] + c2*y[n-1] (from Press) where y is the filtered value, n or n-1 is the data position where n is the most recent value and n-1 is the first past value, and x is the unfiltered data value. The constants c0, c1, and c2 are simply scaling values. The sum of the three constants should be 1.0 so that the filtered data will have the same magnitude as the unfiltered data. c2 determines the weight of the carryover term and a value of 1.0 gives infinite carry forward. You can play with the value of the constants as you write the software to see the different effects. Simply change the formula to y[n] = c0*x[n] - c1*x[n-1] + c2*y[n-1] to make a high pass filter. The relationship of constants to cutoff frequency is dependent upon the sample rate and is beyond my present knowledge. Roger psn-l-digest-request@.............. wrote: > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Newbie trying to get started > From: Steinar Midtskogen > Date: Fri, 20 Jun 2008 22:07:01 +0200 > > Hello List, > > I'm in the process of setting up a seismometer. I was considering a > few options for building one based on internet descriptions, until I > found the SEP seismometer which at £315 seemed likely to turn out > cheaper than all parts needed to build one myself: > > http://www.mutr.co.uk/product_info.php?products_id=9047 > > So I got this seismometer and a quick start. I built a box for it, > and I set up a datalogger. For the datalogger I'm using a Linksys > NSLU2 which is running SlugOS Linux. It's a little box with a 266MHz > ARM processor and 32 MB RAM, plenty for the task. It has ethernet and > two USB ports. I've plugged a card reader into one port, to which > I've connected two flash cards which makes up the filesystem > configured as RAID 1 for added reliability, and the other is used to > connect to the seismometer by a serial cable. > > So far, so good. Now I only need to add some software. I've searched > a bit for existing software, but it turns out to be mostly Windows or > DOS applications with no source code provided, which wont run on an > ARM processor. I think that to use a full blown leftover pc running > Windows for the task is both impractical and expensive. I guess I > have to write some code myself. > > I wrote a small program which logs the data from the seismometer. I > currently plot what I get on this web page (using gnuplot): > > http://voksenlia.net/met/seismometer/ > > What's remaining is some processing prior to plotting. I most likely > need to process my data with a lowpass filter. But then I've run into > a problem. I know very little about signal processing, and I don't > know what type of filter I should use for the best results. Existing > software uses filters it seems, but I haven't found any source code > which could help me out. So I turn to this list. > > I have a 16 bit A/D converter sampling at 20 Hz. My seismometer has a > natural period of about 16 seconds. How should I process the data? > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Newbie trying to get started From: Steinar Midtskogen steinar@............. Date: Sat, 21 Jun 2008 20:04:08 +0200 [rsparks] > Use the formula y[n] = c0*x[n] + c1*x[n-1] + c2*y[n-1] (from Press) Thanks. I'm not sure where to start to find useful values for the constants, though. Perhaps I should log raw data for a while and wait for quakes which I should be able to detect, and then try different combinations to see what makes local noise weaker while preserving the quake signature. My plots at http://voksenlia.net/met/seismometer/ (latest 24 hours) currently show several spikes, all of which were caused by me staying in the room. I can easily play with some simple filters to surpress these, but I can't yet know whether that will also kill interesting seismic signals. I plan to publish my code when I have something that seems to work well. -- Steinar ; NIL DIFFICILE VOLENTI ; http://latinitas.org ; http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Newbie trying to get started From: ChrisAtUpw@....... Date: Sat, 21 Jun 2008 14:54:27 EDT In a message dated 2008/06/21, steinar@............. writes: > My plots at http://voksenlia.net/met/seismometer/ (latest 24 hours) > currently show several spikes, all of which were caused by me staying > in the room. I can easily play with some simple filters to surpress > these, but I can't yet know whether that will also kill interesting > seismic signals. Hi Steinar, Amaseis comes with both a Median filter to cope with this problem and also an anti-glitch setting to eliminate large spikes !! Do check it out! There is a handbook on the AS1 and the use of AmaSeis at http://www.scieds.com/spinet/pdf/AS1AmaSeis.pdf Regards, Chris Chapman In a me= ssage dated 2008/06/21, steinar@............. writes:

My plots at http://voksenlia.ne= t/met/seismometer/ (latest 24 hours)
currently show several spikes, all of which were caused by me staying
in the room.  I can easily play with some simple filters to surpress these, but I can't yet know whether that will also kill interesting
seismic signals.


Hi Steinar,

       Amaseis comes with both a Median filter= to cope with this problem and also an anti-glitch setting to eliminate larg= e spikes !!

       Do check it out! There is a handbook on= the AS1 and the use of AmaSeis at http://www.scieds.com/spinet/pdf/AS1AmaSe= is.pdf

       Regards,

       Chris Chapman
Subject: Re: Newbie trying to get started From: Steinar Midtskogen steinar@............. Date: Sat, 21 Jun 2008 21:39:42 +0200 [rsparks] > Briefly, an Infinite impulse response (IIR) filter is one of the easiest > to use and implement. If you google "iir filter" you will get a > multitude of references, many of which have detailed mathematical > explanations. I searched and found this page: http://www-users.cs.york.ac.uk/~fisher/mkfilter/trad.html I can type in the kind of filter I want, and it will give me C source code for it, along with other useful information about it. Brilliant! -- Steinar ; NIL DIFFICILE VOLENTI ; http://latinitas.org ; http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Program that tells number of events From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sat, 21 Jun 2008 20:42:24 +0000 Hi all Is there a program that can count psn event files and calculate number of events recored. I ask, because I need such program. After the big earthquake on 29th of May 2008 I have been swamped with small earthquakes. I have recored something around 1200 aftershocks (best guess, but aftershocks are still happening). But just week 22 is around 1750 files so far. I am not yet done to fine review the raw data stack on that. After that I have many more days to check. This type of program would be helpful for me to tell me how many events I really have recored. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Digital Filters From: "Robert McClure" bobmcclure90@......... Date: Sat, 21 Jun 2008 17:58:33 -0400 Hi Steinar, I have coded all sorts of digital filters for my seismic applications. Take a look at http://bobmcclure90.googlepages.com/home. I got the most help on Butterworth filters from http://kwon3d.com/theory/datproc.html Kwon does not discuss high pass Butterworth filters, but it is easy to convert a low pass filter design to high pass by simply changing the value of the A coefficients of the filter. My code is all in Visual Basic. You could easily translate it to C. I can give you my code privately if you ask. It is best not to filter the log files. Filtering the heliplot display is acceptable. If you suffer from spikes, it is best to eliminate them at their source. Cheers, Bob McClure __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Tungsten Pins From: "David Saum" DSaum@............ Date: Sat, 21 Jun 2008 18:30:08 -0400 I just got some 1/8" diam x 1.5" Mitsubishi C4 carbide rods from eBay that seem to have a nice polish on them, but under 30x magnification they are covered with fine scratches. Does anyone have any recommendations for polishing techniques for carbide rods? I am guessing that diamond polish is required. Dave > From: "Gary Lindgren" > Date: Mon, 16 Jun 2008 14:44:34 -0700 > > Hi Merdith, > > I just received my Tungsten Carbide 1/8" rods from Centennial Carbide. The > surface finish is excellent and needs no further polishing. Not quite a > mirror finish but very close. I got 10 rods and total cost was $17.30 > including shipping. I would stay away from materials with 'unknown' > description. How do you repeat a result. There plenty of sources at good > prices for both rods and balls. > > Gary __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Tungsten Pins From: ChrisAtUpw@....... Date: Sat, 21 Jun 2008 20:26:00 EDT In a message dated 2008/06/21, DSaum@............ writes: > Does anyone have any recommendations for polishing techniques for carbide > rods? I am guessing that diamond polish is required. Hi Dave, Yes, diamond polishing is required. You can use diamond paste in either oil or water and a copper polishing tool. These can be made from either copper tube, or soild copper with holes bored in it or a U folded copper sheet. The diamond beds into the surface of the copper and does the cutting. You need a fairly coarse paste, at least to start with. I can buy paste in syringes. I use grades labelled coarse and medium. They produce a mirror finish. Regards, Chris Chapman In a me= ssage dated 2008/06/21, DSaum@............ writes:

Does anyone have any recommenda= tions for polishing techniques for carbide rods?  I am guessing that di= amond polish is required.


Hi Dave,

       Yes, diamond polishing is required. You= can use diamond paste in either oil or water and a copper polishing tool. T= hese can be made from either copper tube, or soild copper with holes bored i= n it or a U folded copper sheet.
       The diamond beds into the surface of th= e copper and does the cutting. You need a fairly coarse paste, at least to s= tart with. I can buy paste in syringes. I use grades labelled coarse and med= ium. They produce a mirror finish.

       Regards,

       Chris Chapman
Subject: RE: Tungsten Pins From: "Gary Lindgren" gel@................. Date: Mon, 23 Jun 2008 11:25:41 -0700 Meredith, Refresh my memory of the '3 crossed rod pivot' concept, what does this look like. Gary From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Friday, June 20, 2008 9:14 PM To: psn-l@.............. Subject: Re: Tungsten Pins Hi Chris and all, I think I can now mentally see the very likelyhood of increased friction with two rods and a ball over that of the true 3 crossed rods pivot. Being as the ball is set tightly in a straight linear "groove" (inbetween the two rods), and the horizontal pendulum/boom/pivot ball swings in a slight up-down arc there would logically be some ball arching response rotational rubbing friction of the ball on the two rods trying to accomodate this motion of the boom/mass. Of course; if there was a straight linear motion of the pivot/boom/mass in strict alignment with the two rods and the ball pivot, the ball would simply rotate in a happier more frictionless harmony. Judging from all this rotaton arching nature of the traditonal Lehman; I think it would logically be much better to switch too, or use, the 3 crossed rod pivot. By itself the 3 crossed rod pivot is indeed a excellent choice for a pivot with its ultra-low frictional loss. This is only my choice; but I've not tried them all. Of course there is other pivots used in a Lehman which the builder has a choice of using. Conjecture on the "best" of these will likely go on a long time. Perhaps to ease this gap; it could be possible to have the PSN members simply do a undampened time duration of their announced variety of seismometer pivot, by say a set amount of offset (~ like 1/16" one side of the mass), and simply denote the amount of time till the oscillations obviously disappear on the traces from the normal background noise...this is simply a indication of friction in the pivot. Over time, the "best" pivot variety would likely become more obvious. I've mentioned it before; but I'll mention it again...The Sprengnether "offset wire" pivot they used back in the 1950's, for their horizontal seismometers has been rather a "lost" use pivot. It falls in the torsion aspect as the music wire slightly bends with boom/mass rotation. Theres NO rods, steel/carbide balls or mirror surface etc., required. Probably the best visual basic understanding demonstration of it is in John Lahrs website; specifically for the solid ring and wire shown. If build rigidly, they can literally last "forever". Personally I've never seen one break. The science of these isn't set in stone; so individual experimentation comes into play....which can be fun to do. http://www.jclahr.com/science/psn/gate.html http://www.jclahr.com/science/psn/cor_psn.html Take care, Meredith Lamb On Wed, Jun 18, 2008 at 6:39 PM, wrote: I would like to see a run down pendulum test on this to check it. Regards, Chris

Meredith,

Refresh my memory of the ‘3 crossed rod = pivot’ concept, what does this look like.

Gary

 

 

 

 

From:= psn-l-request@.............. [mailto:psn-l-request@............... On = Behalf Of meredith lamb
Sent: Friday, June 20, 2008 9:14 PM
To: psn-l@..............
Subject: Re: Tungsten Pins

 

Hi Chris and all,

 

I think I can now mentally see the very likelyhood = of increased friction with two rods and a ball over that of = the

true 3 crossed rods pivot.  Being as the ball = is set tightly in a straight linear "groove" (inbetween the two = rods), and

the horizontal pendulum/boom/pivot ball swings in a = slight up-down arc there would logically be some ball

arching response rotational rubbing friction of the = ball on the two rods trying to accomodate this motion of the

boom/mass.

 

Of course; if there was a straight linear motion of = the pivot/boom/mass in strict alignment with the two rods

and the ball pivot, the ball would simply = rotate in a happier more frictionless harmony.

 

Judging from all this rotaton arching = nature of the traditonal Lehman; I think it would logically be much better = to

switch too, or use, the 3 crossed rod = pivot.  By itself the 3 crossed rod pivot is indeed a excellent choice = for

a pivot with its ultra-low frictional loss.  = This is only my choice; but I've not tried them all.

 

Of course there is other pivots used in a Lehman = which the builder has a choice of using.  Conjecture on the

"best" of these will likely go on a = long time.  Perhaps to ease this gap; it could be possible to have the = PSN

members simply do a undampened time duration of their announced variety of seismometer pivot, by say a set = amount

of offset (~ like 1/16" one side of the mass), = and simply denote the amount of time till the oscillations = obviously

disappear on the traces from the normal background noise...this is simply a indication of friction in the pivot.  Over = time,

the "best" pivot variety would likely = become more obvious.

 

I've mentioned it before; but I'll mention it = again...The Sprengnether "offset wire" pivot they used back in the = 1950's,

for their horizontal seismometers has been rather a "lost" use pivot.  It falls in the torsion aspect as the music wire

slightly bends with boom/mass rotation.  = Theres NO rods, steel/carbide balls or mirror surface etc., required.  = Probably

the best visual basic understanding demonstration = of it is in John Lahrs website; specifically for the solid ring = and

wire shown.  If build rigidly, they can = literally last "forever".   Personally I've never seen = one break.  The science of

these isn't set in stone; so individual = experimentation comes into play....which can be fun to do.

 

 

Take care, Meredith Lamb


 

On Wed, Jun 18, 2008 at 6:39 PM, <ChrisAtUpw@.......> = wrote:

       I = would like to see a run down pendulum test on this to check = it. 

 

       = Regards,

       Chris

 

Subject: Re: Tungsten Pins From: "meredith lamb" paleoartifact@......... Date: Mon, 23 Jun 2008 20:29:59 -0600 Hi Gary, Probably pictures are the easiest way to grasp such. Its basically two separated rods, with one cross over rod (as the rotating pivot for the boom). The DSCN5953 picture has a mechanical device which "represents a boom" attachment to the rod...but it can be done via a hole in the pivot boom with a setscrew, possibly a 2 setscrew shaft coupler, etc...but you need to firmly anchor the boom to the rod used. See: http://seismometer.googlepages.com/crossedrodpivot You need to separate the two base/mast rods for stability of the pivot rod, as much as you can; and of course anchor them to your horizontal mast. The web page has no text otherwise, as of yet... BTW.....those mystery balls from the Electronic Goldmine turned out to be brass (ugh) with a unknown surface material thereon. The router bit assortment which had 1/8" shanks of carbide for the most part seemed to have surfaces that appeared to be approaching a mirror surface...but not quite there. .....quite finger smooth. Overall; their surface was much better than I think I'd see from most regular commercially bought ground carbide blanks/rod surfaces. The collars on them are a ceramic which can be easily removed. Take care, Meredith On Mon, Jun 23, 2008 at 12:25 PM, Gary Lindgren wrote: > Meredith, > > Refresh my memory of the '3 crossed rod pivot' concept, what does this look > like. > > Gary > > > > > > > > >
Hi Gary,
 
Probably pictures are the easiest way to grasp such.  Its basically two separated rods, with one
cross over rod (as the rotating pivot for the boom).  The DSCN5953 picture has a mechanical device which
"represents a boom" attachment to the rod...but it can be done via a hole in the pivot boom with a
setscrew, possibly a 2 setscrew shaft coupler, etc...but you need to firmly anchor the boom to the
rod used.  See:
 
 
You need to separate the two base/mast rods for stability of the pivot rod, as much as you can; and of
course anchor them to your horizontal mast. 
 
The web page has no text otherwise, as of yet...
 
BTW.....those mystery balls from the Electronic Goldmine turned out to be brass (ugh) with a unknown
surface material thereon.  The router bit assortment which had 1/8" shanks of carbide for the most
part seemed to have surfaces that appeared to be approaching a mirror surface...but not quite there.
....quite finger smooth.  Overall; their surface was much better than I think I'd see from most regular
commercially bought ground carbide blanks/rod surfaces.  The collars on them are a ceramic which can be
easily removed.   
 
 
Take care, Meredith 

On Mon, Jun 23, 2008 at 12:25 PM, Gary Lindgren <gel@.................> wrote:

Meredith,

Refresh my memory of the '3 crossed rod pivot' concept, what does this look like.

Gary

 

 

 

 

Subject: Can AmaSeis interface via USB? From: alexander mirabal alexmirabal2000@........ Date: Wed, 25 Jun 2008 03:13:19 +0200 (CEST) Hello there, Could you, please, indicate if AmaSeis can interface via USB with an AD Converter? The specific one I have in mind is the National Instruments USB 6009 (8 Analog inputs, 14 bits). I already have one of those since a couple of years ago from other projects and would be great -if possible- using it in this application. http://sine.ni.com/nips/cds/view/p/lang/en/nid/14605 Thanks in advance, Alexander --------------------------------- Enviado desde Correo Yahoo! La bandeja de entrada más inteligente.
Hello there,
 
Could you, please, indicate if AmaSeis can interface via USB with an AD Converter? The specific one I have in mind is the National Instruments USB 6009 (8 Analog inputs, 14 bits). I already have one of those since a couple of years ago from other projects and would be great -if possible- using it in this application.
 
 
Thanks in advance,

Alexander



Enviado desde Correo Yahoo!
La bandeja de entrada más inteligente.
Subject: Re: Can AmaSeis interface via USB? From: John Lahr johnjan@........ Date: Tue, 24 Jun 2008 18:30:47 -0700 On laptop computers with only USB ports, we've had success using a USB to Serial adapter. They are not very expensive. This works when the ADC is of one of the types the AmaSeis knows about. Each ADC has a unique format that AmaSeis must know about. I'll bcc Alan Jones to see if he knows about the NI 6009 ADC. Cheers, John At 06:13 PM 6/24/2008, you wrote: >Hello there, > >Could you, please, indicate if AmaSeis can interface via USB with an >AD Converter? The specific one I have in mind is the National >Instruments USB 6009 (8 Analog inputs, 14 bits). I already have one >of those since a couple of years ago from other projects and would >be great -if possible- using it in this application. > >http://sine.ni.com/nips/cds/view/p/lang/en/nid/14605 > >Thanks in advance, > >Alexander __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Can AmaSeis interface via USB? From: alexander mirabal alexmirabal2000@........ Date: Wed, 25 Jun 2008 04:20:50 +0200 (CEST) Hi again, Thanks John and Alan for your quick response. I absolutely agree about the cost..! Even being in the "low cost" range of NI devices, it is not cheap at all. But having it at hand I wanted to consult you just in case. Yes, I have got involved with the Dataq modules in the past for other application and they are no comparable in cost and very straight forward, but I would like to use a higher resolution if possible (let's say, 16 bits). In that sense, in case I were going to design the AD card, what should be the serial data at the output to properly interface with AmaSeis? Should it already integrates UTC information (taken, lets say, from a GPS), or only the data measured from the filter? Many thanks again, Alex Alan Jones escribió: Alexander, No, AmaSeis does not support the National Instruments USB 6009. The DATAQ devices are very cheap. Why not use one of them? Alan ----- Original Message ----- From: John Lahr To: alexander mirabal ; psn-l@.............. Sent: Tuesday, June 24, 2008 9:30 PM Subject: Re: Can AmaSeis interface via USB? On laptop computers with only USB ports, we've had success using a USB to Serial adapter. They are not very expensive. This works when the ADC is of one of the types the AmaSeis knows about. Each ADC has a unique format that AmaSeis must know about. I'll bcc Alan Jones to see if he knows about the NI 6009 ADC. Cheers, John At 06:13 PM 6/24/2008, you wrote: >Hello there, > >Could you, please, indicate if AmaSeis can interface via USB with an >AD Converter? The specific one I have in mind is the National >Instruments USB 6009 (8 Analog inputs, 14 bits). I already have one >of those since a couple of years ago from other projects and would >be great -if possible- using it in this application. > >http://sine.ni.com/nips/cds/view/p/lang/en/nid/14605>http://sine.ni.com/nips/cds/view/p/lang/en/nid/14605 > >Thanks in advance, > >Alexander --------------------------------- Enviado desde Correo Yahoo! La bandeja de entrada más inteligente.
Hi again,
 
Thanks John and Alan for your quick response.
 
I absolutely agree about the cost..! Even being in the "low cost" range of NI devices, it is not cheap at all. But having it at hand I wanted to consult you just in case.
 
Yes, I have got involved with the Dataq modules in the past for other application and they are no comparable in cost and very straight forward, but I would like to use a higher resolution if possible (let's say, 16 bits).
 
In that sense, in case I were going to design the AD card, what should be the serial data at the output to properly interface with AmaSeis?
 
Should it already integrates UTC information (taken, lets say, from a GPS), or only the data measured from the filter?
 
Many thanks again,
 
Alex
 

Alan Jones <AlanJones@...........> escribió:
Alexander,
 
No, AmaSeis does not support the National Instruments USB 6009. The DATAQ devices are very cheap. Why not use one of them?
 
Alan
 
----- Original Message -----
From: John Lahr
Sent: Tuesday, June 24, 2008 9:30 PM
Subject: Re: Can AmaSeis interface via USB?

On laptop computers with only USB ports, we've had success using a
USB to Serial adapter.  They are not very expensive.  This works when
the ADC is of one of the types the AmaSeis knows about.

Each ADC has a unique format that AmaSeis must know about.  I'll bcc
Alan Jones to see if he knows about the NI 6009 ADC.

Cheers,
John

At 06:13 PM 6/24/2008, you wrote:
>Hello there,
>
>Could you, please, indicate if AmaSeis can interface via USB with an
>AD Converter? The specific one I have in mind is the National
>Instruments USB 6009 (8 Analog inputs, 14 bits). I already have one
>of those since a couple of years ago from other projects and would
>be great -if possible- using it in this application.
>
><http://sine.ni.com/nips/cds/view/p/lang/en/nid/14605>http://sine.ni.com/nips/cds/view/p/lang/en/nid/14605
>
>Thanks in advance,
>
>Alexander




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La bandeja de entrada más inteligente.
Subject: Ruby on carbide...a surprise result From: "meredith lamb" paleoartifact@......... Date: Wed, 25 Jun 2008 18:22:07 -0600 Hi all, Yes another S-G pivot test. This time I tested two round ruby balls on two flat carbide inserts for undampened time oscillation duration; which is a rough indication of pivot friction. The surprise result was that it didn't oscillate near as long as a previous test using magnetic suspension of four common steel ball bearings. http://seismometer.googlepages.com/rubyoncarbide All this indicates; is that a much overall better pivot, is the three crossed rods pivot, for alot less friction. What what little its worth, I also put up another web test page, where magnetics is used with carbide crossed rods to somewhat "assist" the pivot rod in its rotational zero position line aspect. See: http://seismometer.googlepages.com/mcrp Take care, Meredith Lamb
Hi all,
 
Yes another S-G pivot test.  This time I tested two round ruby balls on two flat carbide inserts for undampened
time oscillation duration; which is a rough indication of pivot friction.
 
The surprise result was that it didn't oscillate near as long as a previous test using magnetic suspension
of four common steel ball bearings.
 
 
All this indicates; is that a much overall better pivot, is the three crossed rods pivot, for alot less friction.
 
What what little its worth, I also put up another web test page, where magnetics is used with carbide
crossed rods to somewhat "assist" the pivot rod in its rotational zero position line aspect.  See:
 
 
Take care, Meredith Lamb
 
 
 
 
Subject: Re: Ruby on carbide...a surprise result From: ChrisAtUpw@....... Date: Wed, 25 Jun 2008 23:21:04 EDT In a message dated 2008/06/26, paleoartifact@......... writes: > What what little its worth, I also put up another web test page, where > magnetics is used with carbide crossed rods to somewhat "assist" the pivot rod in > its rotational zero position line aspect. See: > http://seismometer.googlepages.com/mcrp Hi Meredith, Try rotating the rods by 90 degrees so that one lies along the N pole and the other along the S pole. The cross bar will be attracted to them quite strongly. You could probably then use much smaller magnets? Regards, Chris In a me= ssage dated 2008/06/26, paleoartifact@......... writes:

What what little its worth, I a= lso put up another web test page, where magnetics is used with carbide cross= ed rods to somewhat "assist" the pivot rod in its rotational zero position l= ine aspect.  See:  http://seismometer.googlepages.com/mcrp


Hi Meredith,

       Try rotating the rods by 90 degrees so=20= that one lies along the N pole and the other along the S pole. The cross bar= will be attracted to them quite strongly. You could probably then use much=20= smaller magnets?

       Regards,

       Chris
Subject: Re: Ruby on carbide...a surprise result From: "meredith lamb" paleoartifact@......... Date: Thu, 26 Jun 2008 10:47:39 -0600 Hi Chris, Actually what you suggest trying, was actually my first trial model; but it had no rotational zeroing effect on the top pivot rod at all....the rod can be placed anywhere thereon...but yes, it is a a type of holding magnet. When placed directly over the magnet joints as on the web page; when the rod is slightly rotated off the "zeroing line" its immediately magnetically and rotationally attracted back to its original set magnet joint line position. It is yes; a rather weak effect given the size of the mass likely used, but at least the magnet joint "line" is a easy reference to where it should be; at least in that one plane. The same effect can be easily seen with a example single magnet, where if you set the rod on the side/s where the N and S center; it tends to position itself there. Yes...the magnet/s could be considerably smaller; and likewise; so could all the cross rods. I would guess its best application would be in a S-G. Take care, Meredith On Wed, Jun 25, 2008 at 9:21 PM, wrote: > In a message dated 2008/06/26, paleoartifact@......... writes: > > What what little its worth, I also put up another web test page, where > magnetics is used with carbide crossed rods to somewhat "assist" the pivot > rod in its rotational zero position line aspect. See: > http://seismometer.googlepages.com/mcrp > > > > Hi Meredith, > > Try rotating the rods by 90 degrees so that one lies along the N > pole and the other along the S pole. The cross bar will be attracted to them > quite strongly. You could probably then use much smaller magnets? > > Regards, > > Chris
Hi Chris,
 
Actually what you suggest trying, was actually my first trial model; but it had no rotational
zeroing effect on the top pivot rod at all....the rod can be placed anywhere thereon...but yes, it
is a a type of holding magnet.
 
When placed directly over the magnet joints as on the web page; when the rod is slightly rotated
off the "zeroing line" its immediately magnetically and rotationally attracted back to its original set
magnet joint line position.  It is yes; a rather weak effect given the size of the mass likely used, but
at least the magnet joint "line" is a easy reference to where it should be; at least in that one
plane.
 
The same effect can be easily seen with a example single magnet, where if you set the rod on the
side/s where the N and S center; it tends to position itself there.  Yes...the magnet/s could be
considerably smaller; and likewise; so could all the cross rods.
 
I would guess its best application would be in a S-G.
 
Take care, Meredith
 
 


 
On Wed, Jun 25, 2008 at 9:21 PM, <ChrisAtUpw@.......> wrote:
In a message dated 2008/06/26, paleoartifact@......... writes:

What what little its worth, I also put up another web test page, where magnetics is used with carbide crossed rods to somewhat "assist" the pivot rod in its rotational zero position line aspect.  See:  http://seismometer.googlepages.com/mcrp


Hi Meredith,

       Try rotating the rods by 90 degrees so that one lies along the N pole and the other along the S pole. The cross bar will be attracted to them quite strongly. You could probably then use much smaller magnets?

       Regards,

       Chris

Subject: Earthquake 2008-06-27 From: Steinar Midtskogen steinar@............. Date: Fri, 27 Jun 2008 16:01:19 +0200 Hello, With the help of this list I managed to make a lowpass filter at 0.5 Hz and I also got various tips for improving the case. I got it up and running in an improved state yesterday and all was set for a quake to test it. I noticed some pretty strong distortions beginning 11:52 UTC today and picking up a lot about 12:24. I checked www.usgs.gov and there was a 6.7 quake off India at 11:40, which I presume is a candidate. My location is Oslo, Norway. Since I'm totally new to seismology, would anyone on this list comment on the plot that my seismometer produced, does it look like a quake and does my seismometer seem to work properly? Here's a plot of the incident: http://voksenlia.net/nytt/2008/seismo-20080627c.jpg Live data for the past 24 hours on: http://voksenlia.net/met/seismometer/ Thanks, -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: tchannel1@............ Date: Fri, 27 Jun 2008 09:09:51 -0600 Hi Steinar, This looks just great to me! Well done. Please tell us about your sensor. If you post your .psn data file we all can see it in detail. Do you know how to do this? Ted, in Boise Idaho USA ----- Original Message ----- From: "Steinar Midtskogen" To: Sent: Friday, June 27, 2008 8:01 AM Subject: Earthquake 2008-06-27 > Hello, > > With the help of this list I managed to make a lowpass filter at 0.5 > Hz and I also got various tips for improving the case. I got it up > and running in an improved state yesterday and all was set for a quake > to test it. > > I noticed some pretty strong distortions beginning 11:52 UTC today and > picking up a lot about 12:24. I checked www.usgs.gov and there was a > 6.7 quake off India at 11:40, which I presume is a candidate. My > location is Oslo, Norway. > > Since I'm totally new to seismology, would anyone on this list comment > on the plot that my seismometer produced, does it look like a quake > and does my seismometer seem to work properly? > > Here's a plot of the incident: > > http://voksenlia.net/nytt/2008/seismo-20080627c.jpg > > Live data for the past 24 hours on: http://voksenlia.net/met/seismometer/ > > Thanks, > -- > Steinar Midtskogen > http://voksenlia.net > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: Steinar Midtskogen steinar@............. Date: Fri, 27 Jun 2008 17:16:56 +0200 writes: > Hi Steinar, This looks just great to me! Well done. Please tell > us about your sensor. If you post your .psn data file we all can see > it in detail. Do you know how to do this? It's a SEP seismometer oriented north-south and the period is about 20 seconds. The software is my own. I have the raw data stored, but I need to know the format of .psn data in order to convert it. Is it documented somewhere? -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: "Jerry Payton" gpayton880@....... Date: Fri, 27 Jun 2008 10:21:38 -0500 Steiner, I believe you will find this at http://www.seismicnet.com/psnformat4.html Regards, Jerry ----- Original Message ----- From: Steinar Midtskogen To: psn-l@.............. Sent: Friday, June 27, 2008 10:16 AM Subject: Re: Earthquake 2008-06-27 writes: > Hi Steinar, This looks just great to me! Well done. Please tell > us about your sensor. If you post your .psn data file we all can see > it in detail. Do you know how to do this? It's a SEP seismometer oriented north-south and the period is about 20 seconds. The software is my own. I have the raw data stored, but I need to know the format of .psn data in order to convert it. Is it documented somewhere? -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Steiner,
 
I believe you will find this at   http://www.seismicnet.= com/psnformat4.html
 
Regards,
Jerry
 
 
----- Original Message -----=20
From: Steinar=20 Midtskogen
Sent: Friday, June 27, 2008 10:16 AM
Subject: Re: Earthquake 2008-06-27

<tchannel1@............>=20 writes:

> Hi Steinar,   This looks just great to=20 me!   Well done.  Please tell
> us about your = sensor. =20 If you post your .psn data file we all can see
> it in = detail.  Do=20 you know how to do this?

It's a SEP seismometer oriented = north-south and=20 the period is about 20
seconds.  The software is my = own.

I have=20 the raw data stored, but I need to know the format of .psn
data in = order to=20 convert it.  Is it documented somewhere?

--
Steinar=20 Midtskogen
http://voksenlia.net
_______________= ___________________________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Earthquake 2008-06-27 From: "Jerry Payton" gpayton880@....... Date: Fri, 27 Jun 2008 10:23:13 -0500 I believe that you will find what you want here: http://www.seismicnet.com/psnformat4.html ----- Original Message ----- From: Steinar Midtskogen To: psn-l@.............. Sent: Friday, June 27, 2008 10:16 AM Subject: Re: Earthquake 2008-06-27 writes: > Hi Steinar, This looks just great to me! Well done. Please tell > us about your sensor. If you post your .psn data file we all can see > it in detail. Do you know how to do this? It's a SEP seismometer oriented north-south and the period is about 20 seconds. The software is my own. I have the raw data stored, but I need to know the format of .psn data in order to convert it. Is it documented somewhere? -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
I believe that you will find what you want here:   http://www.seismicnet.= com/psnformat4.html
 
 
 
----- Original Message -----=20
From: Steinar=20 Midtskogen
Sent: Friday, June 27, 2008 10:16 AM
Subject: Re: Earthquake 2008-06-27

<tchannel1@............>=20 writes:

> Hi Steinar,   This looks just great to=20 me!   Well done.  Please tell
> us about your = sensor. =20 If you post your .psn data file we all can see
> it in = detail.  Do=20 you know how to do this?

It's a SEP seismometer oriented = north-south and=20 the period is about 20
seconds.  The software is my = own.

I have=20 the raw data stored, but I need to know the format of .psn
data in = order to=20 convert it.  Is it documented somewhere?

--
Steinar=20 Midtskogen
http://voksenlia.net
_______________= ___________________________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Earthquake 2008-06-27 From: Bob Hancock carpediem1@......... Date: Fri, 27 Jun 2008 08:44:50 -0700 Steiner - You appear to have recorded both the main event M 6.6, and a large aftershock at M 6.1 - Nice work. Bob Hancock - Three Points, AZ, USA On 6/27/08 8:16 AM, "Steinar Midtskogen" wrote: > > > It's a SEP seismometer oriented north-south and the period is about 20 > seconds. The software is my own. > > I have the raw data stored, but I need to know the format of .psn > data in order to convert it. Is it documented somewhere? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Using AmaSeis to help with seismogram interpretation From: John Lahr johnjan@........ Date: Fri, 27 Jun 2008 11:10:08 -0700 At 10:49 AM 6/27/2008, you wrote: >Delivery failed >Message too large for this mailing list I tried sending a message with graphics, but exceeded the limits of the mailing list. So I've posted my message here: http://jclahr.com/science/psn/india/ Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: Steinar Midtskogen steinar@............. Date: Fri, 27 Jun 2008 20:57:43 +0200 John Lahr writes: > Nice recording! > > You can use this on-line site to compute the expected arrival times of various > phases to your station: > http://neic.usgs.gov/neis/travel_times/index.html > > This can help in interpretation. For my location (60.0N 10.7E) I got: travel arrival time # code time(s) dy hr mn sec 1 P 704.23 0 11 52 1 2 PKiKP 1049.62 0 11 57 46 3 S 1285.99 0 12 1 42 4 SKSac 1311.44 0 12 2 8 5 LQ 1932.02 0 12 12 29 6 LR 2144.27 0 12 16 1 Pretty neat. My station recorded the first rise at 11:52. The next event happens at 12:02, and the really big rumble begins 12:20 and lasts 20 minutes. So the "P" seems dead on, while the next events showed up a bit belated. > Also, once you have saved the seismogram in .sac format you can use > AmaSeis as an analysis tool. I'll look into that format as well. Is there a way to convert between ..psn to .sac? -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: Steinar Midtskogen steinar@............. Date: Fri, 27 Jun 2008 22:08:14 +0200 writes: > Hi Steinar, This looks just great to me! Well done. Please tell > us about your sensor. If you post your .psn data file we all can see > it in detail. Do you know how to do this? Somebody e-mailed me some code which helped me out, and I've put the ..psn file here: http://voksenlia.net/nytt/2008/seismo-20080627.psn It starts at 11:00:01 UTC. I don't have any programs able to read ..psn files, so I can't be sure that the format is valid, so please let me know if it's unreadable. -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: Mark Robinson mark.robinson@............... Date: Sat, 28 Jun 2008 08:33:31 +1200 Steinar Midtskogen wrote: > John Lahr writes: >> Nice recording! >> You can use this on-line site to compute the expected arrival times of various >> phases to your station: >> http://neic.usgs.gov/neis/travel_times/index.html >> This can help in interpretation. > > For my location (60.0N 10.7E) I got: > > travel arrival time > # code time(s) dy hr mn sec > 1 P 704.23 0 11 52 1 > 2 PKiKP 1049.62 0 11 57 46 > 3 S 1285.99 0 12 1 42 > 4 SKSac 1311.44 0 12 2 8 > 5 LQ 1932.02 0 12 12 29 > 6 LR 2144.27 0 12 16 1 > > Pretty neat. My station recorded the first rise at 11:52. The next > event happens at 12:02, and the really big rumble begins 12:20 and > lasts 20 minutes. So the "P" seems dead on, while the next events > showed up a bit belated. > >> Also, once you have saved the seismogram in .sac format you can use >> AmaSeis as an analysis tool. > > I'll look into that format as well. Is there a way to convert between > .psn to .sac? Congratulations Steinar. I don't remember seeing Seismic Toolkit mentioned here so members may also be interested to look at it: http://seismic-toolkit.sourceforge.net/ You can download a windows binary or source which will build on most *n.x|*bsd platforms. It also requires SAC files. -- regards Mark Robinson __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: ChrisAtUpw@....... Date: Fri, 27 Jun 2008 16:45:11 EDT In a message dated 2008/06/27, steinar@............. writes: > It starts at 11:00:01 UTC. I don't have any programs able to read > .psn files, so I can't be sure that the format is valid, so please let > me know if it's unreadable. Hi Steinar, It is unreadable in my Winquake. It generates a string of errors. Have you checked the format at psn.quake.net? There is also a large header. Have you bought Winquake? Why not use hourly .sac files? AmaSeis reads those. Regards, Chris Chapman In a me= ssage dated 2008/06/27, steinar@............. writes:

It starts at 11:00:01 UTC. = ; I don't have any programs able to read
..psn files, so I can't be sure that the format is valid, so please let
me know if it's unreadable.


Hi Steinar,

       It is unreadable in my Winquake. It gen= erates a string of errors. Have you checked the format at psn.quake.net? The= re is also a large header. Have you bought Winquake?
       Why not use hourly .sac files? AmaSeis=20= reads those.

       Regards,

       Chris Chapman
Subject: New addition to map and database From: Dave Nelson davenn@............... Date: Sat, 28 Jun 2008 09:28:30 +1000 Greetings to all, I would like to welcome James Ridout to the group, his station is now listed on the map and in the database. James hails from the Bedfordshire area in the UK. As a side note I am in the process of generating a new better quality map for the UK/Europe region and for Tony's joy ;) a new one to cover the Hawaii area is also under way. Dont forget the maps and database can be access from the main page of http://www.sydneystormcity.com/map.htm If you are not listed and would like to be, please send me you station data in the format listed at the bottom of any of the map pages. If you are listed then its a good time to check your listed data and let me know of any updates to the info :) cheers Dave Nelson Sydney Australia __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New addition to map and database From: John Lahr johnjan@........ Date: Fri, 27 Jun 2008 19:02:57 -0700 Dave, Thanks for keeping up the PSN map and station list. One suggestion, for new additions, would be to add the date of the addition. I tried to contact the PSN member living and Portland and my message bounced. Does anyone know if Walt still lives in Oregon? Walt, are you still on the list? NAME: Walt Catino E-MAIL: wcatino@............. Cheers, John At 04:28 PM 6/27/2008, you wrote: >Greetings to all, > > I would like to welcome James Ridout to the group, his station is now >listed on the map and in the database. > James hails from the Bedfordshire area in the UK. > > As a side note I am in the process of generating a new better quality map >for the UK/Europe region and for Tony's joy ;) a new one to >cover the Hawaii >area is also under way. > >Dont forget the maps and database can be access from the main page of >http://www.sydneystormcity.com/map.htm > >If you are not listed and would like to be, please send me you station data in >the format listed at the bottom of any of the map pages. > >If you are listed then its a good time to check your listed data and >let me know >of any updates to the info :) > >cheers >Dave Nelson >Sydney >Australia #################################/ John C. Lahr ################################/ Emeritus Seismologist ###############################/ U.S. Geological Survey ==========================/ Central Region Geologic Hazards Team #############################//################################# ############################//################################## PO Box 548 /################################### Corvallis, Oregon 97339 /=============================== Phone: (541) 758-2699 /#################################### Cell: (541) 740-4844 /##################################### Fax: (413) 658-2699 /###################################### johnjan@........ /####################################### http://jclahr.com/science/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Oregon PSN From: John Lahr johnjan@........ Date: Fri, 27 Jun 2008 19:34:14 -0700 Does anyone have a current address for Al Allworth? My message to him bounced back: Unknown user: Allworth@.............. Thanks, John NAME: Al Allworth W7PXX E-MAIL: Allworth@.............. TOWN/CITY: Gold Beach STATE: Oregon LAT./LONG: 42.51N 124.33W CH1: COM; Mark Products 1 Hz model L-4. GROUND TYPE: located .5 mile from the Pacific Ocean on bedrock of Jurassic age, composed of sedimentary and volcanic deposits. Very close to alluvial deposits of sand, gravel and silt. I see a lot of motion from wave action. Hi Al, I was thinking about getting the Oregon PSN members together for an informal meeting some time. Gold Hill is quite a distance from Corvallis and Salem, where Robert L. Laney, Steve Clark, and I live. Do you ever have occasion to get up this way? We could try to schedule something around a trip that you're making anyway. When I was running the seismograph network in southern Alaska for the USGS we used L4 1 Hz seismometers. They were very reliable and just right for local and regional events. It took a really large magnitude to see any surface waves from a distant event, however. Of course from our point of view, this was just noise! Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New addition to map and database From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sat, 28 Jun 2008 03:27:39 +0000 Hi all I don't think my Hekla station has been added to the database. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New addition to map and database From: ChrisAtUpw@....... Date: Sat, 28 Jun 2008 00:39:58 EDT In a message dated 2008/06/28, davenn@............... writes: > If you are listed then its a good time to check your listed data and let me > > know of any updates NAME: Chris Chapman (22) E-MAIL: ChrisAtUpwantispam@....... (remove the... antispam ...from addy) TOWN/CITY: Nr. Chichester Hi Dave, Please add: CHUK Developement AS1 type seismometer. Period 1 sec to 20 sec. NdFeB quad Magnet + Copper plate 0.7 critical damping. Regards, Chris Chapman In a me= ssage dated 2008/06/28, davenn@............... writes:

If you are listed then its a go= od time to check your listed data and let me
know of any updates


NAME: Chris Chapman (22)
E-MAIL: ChrisAtUpwantispam@....... (remove the...  antispam ...from ad= dy)
TOWN/CITY: Nr. Chichester

Hi Dave,

       Please add:

       CHUK Developement AS1 type seismometer.= Period 1 sec to 20 sec. NdFeB quad Magnet + Copper plate 0.7 critical dampi= ng.

       Regards,

       Chris Chapman
Subject: Re: Earthquake 2008-06-27 From: Steinar Midtskogen steinar@............. Date: Sat, 28 Jun 2008 07:44:16 +0200 [ChrisAtUpw@........ > It is unreadable in my Winquake. It generates a string of errors. Have > you checked the format at psn.quake.net? There is also a large header. Have you > bought Winquake? > Why not use hourly .sac files? AmaSeis reads those. I've tried to install AmaSeis now. Since I run Linux, I need to run it through Wine. AmaSeis didn't work at all on my regular AMD64 pc, but it does run using Wine on my older Pentium pc. I downloaded the Seismic ToolKit from sourceforge, which contain code able to read .sac files, so I should be able to figure out how to write them as well. For the time being, I store my data in a simple raw format: as 16 bit values from -32767 to +32768. -32768 (0x8000) means that a 32 bit timestamp will follow, which I usually store every five seconds. I use big endian byte ordering. -- Steinar Midtskogen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: "Dale Hardy" photon1@........... Date: Sat, 28 Jun 2008 16:35:03 +1000 Hi Steinar, Bob has a utility program to convert from SAC to PSN at http://bobmcclure90.googlepages.com/winsac regards Dale ----- Original Message ----- From: "Steinar Midtskogen" To: Sent: Saturday, June 28, 2008 3:44 PM Subject: Re: Earthquake 2008-06-27 > [ChrisAtUpw@........ > >> It is unreadable in my Winquake. It generates a string of errors. >> Have >> you checked the format at psn.quake.net? There is also a large header. >> Have you >> bought Winquake? >> Why not use hourly .sac files? AmaSeis reads those. > > I've tried to install AmaSeis now. Since I run Linux, I need to run > it through Wine. AmaSeis didn't work at all on my regular AMD64 pc, > but it does run using Wine on my older Pentium pc. > > I downloaded the Seismic ToolKit from sourceforge, which contain code > able to read .sac files, so I should be able to figure out how to > write them as well. > > For the time being, I store my data in a simple raw format: as 16 bit > values from -32767 to +32768. -32768 (0x8000) means that a 32 bit > timestamp will follow, which I usually store every five seconds. I > use big endian byte ordering. > > -- > Steinar Midtskogen > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > > -- > Internal Virus Database is out-of-date. > Checked by AVG. > Version: 7.5.524 / Virus Database: 270.4.1 - Release Date: 19/06/2008 > 12:00 AM > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New addition to map and database From: "Thomas Dick" dickthomas01@............. Date: Sat, 28 Jun 2008 07:52:37 -0500 Question: why post this information? Isn't it part of the sensor information? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New addition to map and database From: Dave Nelson davenn@............... Date: Sat, 28 Jun 2008 23:55:41 +1000 Thomas specifically what info are you referring to ? Dave N At 07:52 AM 6/28/2008 -0500, you wrote: >Question: why post this information? Isn't it part of the sensor information? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: Steinar Midtskogen steinar@............. Date: Sat, 28 Jun 2008 19:54:09 +0200 [ChrisAtUpw@........ > Why not use hourly .sac files? AmaSeis reads those. I found a document describing the sac format, so I made a quick program to convert my data into it. I'm not sure whether all the headers get written correctly, but AmaSeis seems to be able to read the files I make. I've put a sac file for yesterday's quake here: http://voksenlia.net/nytt/2008/seismo-20080627.sac From 11:40 UTC (time of the earthquake) till 13:40 UTC. I've also made the programs I've written so far available here: http://voksenlia.net/met/seismometer/ (At the bottom of the page) I noticed a new quake in my plots today, a bit weaker, but quite clear. It matches a 6.3 quake in the same area as yesterday (according to www.usgs.gov). -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: "Robert McClure" bobmcclure90@......... Date: Sat, 28 Jun 2008 15:01:16 -0400 Hi Steinar, I download your sac file and converted it to PSN format. I wasn't able to make sense of it until I realized the time on it was 2 hours ahead of UTC. Remember to use UTC, not your local time. Have you downloaded WinQuake yet? You cannot fully participate in the PSN until you do. Bob >I've put a sac file for yesterday's quake here:http://voksenlia.net/nytt/2008/seismo->20080627.sacFrom 11:40 UTC (time of the earthquake) till 13:40 UTC. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: Steinar Midtskogen steinar@............. Date: Sat, 28 Jun 2008 21:46:57 +0200 [Robert McClure] > I download your sac file and converted it to PSN format. I wasn't > able to make sense of it until I realized the time on it was 2 hours > ahead of UTC. Remember to use UTC, not your local time. Thanks for pointing that out. I am two hours ahead of UTC, but the error was in fact that I put the end time (two hours) in the headers. I forgot that gmtime in C uses a statically allocated struct, so it overwrites the previous result when it's called again. I've replaced the sac file with a correct one. > Have you downloaded WinQuake yet? You cannot fully participate in > the PSN until you do. I just did. It did not run at all on my regular AMD64 pc, but it seems to run on my older Pentium pc, though as with AmaSeis there are some refresh problems, probably due to shortcomings of Wine (I run Linux, and I haven't done any upgrades for many years on the Pentium). Also, things are pretty sluggish, since I have to run the program remotely. Does WinQuake have any major advantages over AmaSeis? Since WinQuake isn't free, I'm a bit reluctant to use it in Linux which apparently isn't glitch free and probably not supported. -- Steinar Midtskogen http://voksenlia.net __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake 2008-06-27 From: "Robert McClure" bobmcclure90@......... Date: Sat, 28 Jun 2008 21:22:07 -0400 Winquake allows you to post event on the PSN web site. It also alows the automatic marking of phases. I would be lost without WinQuake. It also has a world map showing the location of your station and the event. It offers so much more than a SAC file. I am sending you another email about what I found wrong with your data acquisition. On 6/28/08, Steinar Midtskogen wrote: > [Robert McClure] > >> I download your sac file and converted it to PSN format. I wasn't >> able to make sense of it until I realized the time on it was 2 hours >> ahead of UTC. Remember to use UTC, not your local time. > > Thanks for pointing that out. I am two hours ahead of UTC, but the > error was in fact that I put the end time (two hours) in the headers. > I forgot that gmtime in C uses a statically allocated struct, so it > overwrites the previous result when it's called again. I've replaced > the sac file with a correct one. > >> Have you downloaded WinQuake yet? You cannot fully participate in >> the PSN until you do. > > I just did. It did not run at all on my regular AMD64 pc, but it > seems to run on my older Pentium pc, though as with AmaSeis there are > some refresh problems, probably due to shortcomings of Wine (I run > Linux, and I haven't done any upgrades for many years on the Pentium). > Also, things are pretty sluggish, since I have to run the program > remotely. > > Does WinQuake have any major advantages over AmaSeis? Since WinQuake > isn't free, I'm a bit reluctant to use it in Linux which apparently > isn't glitch free and probably not supported. > > -- > Steinar Midtskogen > http://voksenlia.net > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Al Allworth From: John Lahr johnjan@........ Date: Sun, 29 Jun 2008 17:24:38 -0700 Dear Charles, Thanks for letting me know. I'm very sorry to hear about Al. We have far to few amateurs involved in seismology, so can't afford to loose any of them! I'll cc the psn list to bring everyone up to date with the sad news. Yours, John At 10:59 AM 6/28/2008, you wrote: >Hello John: > >I subscribe to the PSN mail list and saw your inquiry about Al >Allworth. I happen to have an interest in amateur seismology and >contacted Al via e-mail several years ago about his sensor but never >did meet him face to face. I live about 30 miles from where he lived >on the southern coast of Oregon and happened to see an obituary for >him in the local newspaper indicating that he passed away in 2002. I >do not know what happened to his seismographic sensor and there is >no telephone listing for the Allworth family in the local directory. > >Sorry to be the bearer of sad news but I thought you would like to know. > >Regards, > >Chuck Nordstrom >P.O. Box 121 >Langlois, OR 97450 >E-mail: cen@.............. > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Oregon Public Seismic Network (PSN) From: John or Jan Lahr JohnJan@........ Date: Sun, 29 Jun 2008 18:21:25 -0700 So far a I can determine, the following are the=20 only PSN-list subscribers, active PEPP=20 participants, or AS-1-trained K-12 teachers=20 living in Oregon. Please let me know if I'm missing anyone. At some point this summer it would be good to get=20 together to compare notes and talk about=20 amateur/educational seismic monitoring. Please=20 let me know if you would be interested. Cheers, John Chuck Nordstrom P.O. Box 121 Langlois, OR 97450 E-mail: cen@.............. NAME: Robert L. Laney E-MAIL: faultquake@....... TOWN/CITY: Salem STATE: Oregon COUNTRY: USA LAT./LONG: 44.863N 123.031W 401ft (122m) AMSL CH1: HB; W (S80=B0W); Lehman; .RL1 CH2: HB; N (N10=B0W); S-G High frequency output; .RL2 CH3: HB; N (N10=B0W); S-G Low frequency output; .RL3 A to D: 3-chan. ampl/fil brd from L.=20 Cochrane, 16 bit SDR; WWV time corr. GROUND TYPE: Sensors are on concrete floor at=20 ground level. Underlying material is about 20 feet of stream alluvium over Miocene Columbia River Basalt NAME: Walt=20 Catino (29) E-MAIL: wcatino@............. TOWN/CITY: Portland STATE/PROV: Oregon COUNTRY: USA LAT/LONG: 45.42N 123.04W CH1: N; Mod. Wood-Anderson CH2: E; Mod. Wood-Anderson CH3: Cheapie 15 Hz V g/phone A TO D: 12 bit SDR DRUM: Kinematics drum with timecode ticks GND TYPE: mosty clay with rock down below Rod Humphrey" Technology Director Umatilla School District 541.922.6562 http://www.umatilla.k12.or.us (May not be on the PSN list, but participated in=20 the PEPP (Princeton Earth Physics Program) a few years ago) Web site: http://www.umatilla.k12.or.us/seismoweb/index.html Kay & Steve=20 Wyatt=20 <info= @................> Oregon Shakes Program http://oregonshakes.com/about/Kay.html "Our goal is to place a seismograph in all public=20 schools in Lincoln County, Oregon, and to provide=20 educational resources, volunteers, and activities=20 to help people understand the seismograph." Depoe Bay, Kids' Zone AS-1 helicorder=20 record: http://www.iris.edu/amaseis/schools/fullview.phtml?code=3DDEPOE The following have been given or taken seismology=20 workshops involving the AS-1 seismometer system: 2006 Workshop presenters: Jenda Johnson (Operates an AS-1) Prof. Robert Butler (Operates an AS-1) John Lahr (Operates two AS-1's=20 and a horizontal: http://jclahr.com/science/psn/chor/) K-12 Portland teacher participants, some of whom=20 are operating classroom AS-1 systems: Roy Chambers Bruce Reiter Carol Pinegar , Edwin Wack , Gerilyn Nichols , Joanne Barta , Kelly Allen , Misty Scevola , Rod Kitson , Ric Oleksak , Tom Bright , Vanessa Crock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Al Allworth From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Mon, 30 Jun 2008 01:48:21 +0000 Hi There are not big amount of information on the internet. But I found this. ----- NORMAN ALLWORTH Norman Dale Allworth, 67, died Nov. 18, 2003 in Lacey. Allworth was born Feb. 24, 1936 in Portland, worked as a chemical and environmental engineer including work on environmental cleanup projects, and retired in 1998. Allworth was a long-time Battle Ground resident until moving to Lacey three years ago. Allworth attended Oregon State University. He served in the U.S. Marine Corps. He enjoyed contract bridge, sailing, kayaking, river rafting, rock hounding, mushroom hunting, hiking and RVing. He had lived in the San Francisco area, Los Angeles area, Beaverton and Coos Bay, OR, Bellingham, Puyallup, and Salt Lake City. Allworth was preceded in death by brother Al Allworth in 2002, and grandson Nathan Machock in 2001. Survivors include widow Leilani Allworth, at home, step-daughter Heidi Machock of California, sons Dave Allworth and Dan Allworth, both of Oregon, and Randy Allworth of Seattle, step-sons Brian Alonzo of Tumwater and David Alonzo of Seattle, sister Barbara Browning of Washougal, brothers Bob Allworth of Louisiana and George Allworth of Oregon, and 11 grandchildren. Funeral services will be held Tues., Nov. 25, 1 p.m., at Layne's Funeral Home Chapel, Battle Ground, with committal at Crawford Cemetery, Battle Ground. Layne's Funeral Home is in charge of arrangements. Source: http://www.thereflector.com/PAGES/STORIES/Old% 20Stories/2003/11-26-03.html ------ Regards. J=F3n Fr=EDmann. On Sun, 2008-06-29 at 17:24 -0700, John Lahr wrote: > Dear Charles, >=20 > Thanks for letting me know. I'm very sorry to hear about Al. We=20 > have far to few amateurs involved in seismology, so can't afford to=20 > loose any of them! >=20 > I'll cc the psn list to bring everyone up to date with the sad news. >=20 > Yours, > John >=20 > At 10:59 AM 6/28/2008, you wrote: > >Hello John: > > > >I subscribe to the PSN mail list and saw your inquiry about Al=20 > >Allworth. I happen to have an interest in amateur seismology and=20 > >contacted Al via e-mail several years ago about his sensor but never=20 > >did meet him face to face. I live about 30 miles from where he lived=20 > >on the southern coast of Oregon and happened to see an obituary for=20 > >him in the local newspaper indicating that he passed away in 2002. I=20 > >do not know what happened to his seismographic sensor and there is=20 > >no telephone listing for the Allworth family in the local directory. > > > >Sorry to be the bearer of sad news but I thought you would like to know. > > > >Regards, > > > >Chuck Nordstrom > >P.O. Box 121 > >Langlois, OR 97450 > >E-mail: cen@.............. > > > > > > >=20 >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email PSN-L-REQUEST@.............. with=20 > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L)