Subject: Man Made Quake From: John Popelish jpopelish@........ Date: Fri, 31 Mar 2006 17:26:31 -0500 Is anyone planning on trying to capture this bump? http://www.military.com/NewsContent/0,13319,92910,00.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Man Made Quake From: "Coleman, Allan" allan.coleman@............ Date: Fri, 31 Mar 2006 15:02:19 -0800 Talking of capturing planned "bumps", mark this one on your calendar = also.=20 http://www.worldjumpday.org/ Comments, thoughts etc from anyone on this event? =20 Allan -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of John Popelish Sent: Friday, March 31, 2006 2:27 PM To: psn-l@.............. Subject: Man Made Quake Is anyone planning on trying to capture this bump? http://www.military.com/NewsContent/0,13319,92910,00.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: 2006 SF Quake From: Larry Cochrane lcochrane@.............. Date: Fri, 31 Mar 2006 23:13:19 -0800 I too would like to attend. Either day works for me. Larry Cochrane Redwood City, PSN Keith Payea wrote: > All: > > I'm up for it. Either day is fine. If everyone interested chimes in, we > can get an idea of how many to accommodate. > > Keith Payea > Santa Rosa, CA > > -----Original Message----- > From: psn-l-request@.............. [mailto:psn-l-request@............... On > Behalf Of Richard Webb > Sent: Friday, March 31, 2006 5:59 AM > To: psn-l@.............. > Subject: Re: 2006 SF Quake > > John, > > I think an informal get together on either day would be great. > > Dick > > John or Jan Lahr wrote: >> I'll be attending the meeting. Maybe we should have an informal PSN >> meeting one evening? >> Tuesday or Wednesday would be the best for me. (April 18 or 19). >> >> Cheers, >> John >> >> At 02:31 PM 3/29/2006, you wrote: >>> Hi, >>> >>> The SSA is having the 2006 meeting in SF the week of April 17. Are >>> any PSN types going to be there? >>> >>> Dick >>> Raleigh, NC >>> __________________________________________________________ >>> >>> 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) > > 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: Man Made Quake From: ChrisAtUpw@....... Date: Sat, 1 Apr 2006 12:49:54 EST In a message dated 01/04/2006, allan.coleman@............ writes: Talking of capturing planned "bumps", mark this one on your calendar also. http://www.worldjumpday.org/ Comments, thoughts etc from anyone on this event? Hi Allan, The Earth's mass is app 6.10^24 kg. The population is 6.6.10^9. If the average weight were (guess) 50 kg, this would make 3.3.10^11 kg. This gives a ratio of 1.8.10^13 which is slightly small. Perhaps one should look at what other motives there could be for promoting this event? Regards, Chris Chapman
In a message dated 01/04/2006, allan.coleman@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Talking=20 of capturing planned "bumps", mark this one on your calendar also.=20
http://www.worldjumpday.org/

Comments, thoughts etc from anyone= on=20 this event? 
Hi Allan,
 
    The Earth's mass is app 6.10^24 kg. The populat= ion=20 is 6.6.10^9. If the average weight were (guess) 50 kg, this would make 3.3.1= 0^11=20 kg. This gives a ratio of 1.8.10^13 which is slightly small.
    Perhaps one should look at what other motives t= here=20 could be for promoting this event?
 
    Regards,
 
    Chris Chapman
Subject: Re: Man Made Quake From: ian ian@........... Date: Sat, 01 Apr 2006 19:36:36 +0100 conservation of angular momentum might also influence things even if the orbit was changed (temporarily). Kepler's laws of motion are kind of against you too. You also have a cancellation effect caused by the jumping forces being on opposite sides of the planet, sort of. It's more like 1st of April stuff, though to set up a website just for that is a bit extreme... Ian ChrisAtUpw@....... wrote: > In a message dated 01/04/2006, allan.coleman@............ writes: > > Talking of capturing planned "bumps", mark this one on your > calendar also. > http://www.worldjumpday.org/ > > Comments, thoughts etc from anyone on this event? > > Hi Allan, > > The Earth's mass is app 6.10^24 kg. The population is 6.6.10^9. If > the average weight were (guess) 50 kg, this would make 3.3.10^11 kg. > This gives a ratio of 1.8.10^13 which is slightly small. > Perhaps one should look at what other motives there could be for > promoting this event? > > Regards, > > Chris Chapman conservation of angular momentum might also influence things even if the orbit was changed (temporarily).  Kepler's laws of motion are kind of against you too.  You also have a cancellation effect caused by the jumping forces being on opposite sides of the planet, sort of.

It's more like 1st of April stuff, though to set up a website just for that is a bit extreme...

Ian

ChrisAtUpw@....... wrote:
In a message dated 01/04/2006, allan.coleman@............ writes:
Talking of capturing planned "bumps", mark this one on your calendar also.
http://www.worldjumpday.org/

Comments, thoughts etc from anyone on this event? 
Hi Allan,
 
    The Earth's mass is app 6.10^24 kg. The population is 6.6.10^9. If the average weight were (guess) 50 kg, this would make 3.3.10^11 kg. This gives a ratio of 1.8.10^13 which is slightly small.
    Perhaps one should look at what other motives there could be for promoting this event?
 
    Regards,
 
    Chris Chapman
Subject: Arizona Earthquake this morning From: "Geoffrey" gmvoeth@........... Date: Sun, 2 Apr 2006 11:54:41 -0700 Howdy All: Did anyone receive this EQ this morning ? All I could tell is the following: Station: formerly GVA possibly listed as closed Apache Junction Arizona reception time: 18:11:47 2006APR02 UTC S-P : 25 seconds delta: 1.7 to 1.8 degrees mag: probably less than 3 on the Richter scale. Regards; gmvoeth __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: speaking about bad luck From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 03 Apr 2006 03:12:32 +0000 Hi Ian and everybody else. I find it bad to miss a earthquake becose it has to happen the same day that i need to work on my geophone or the computer. I have lost two earthquakes so far, becose i was working on my geophone or becose of hardware failure in the computer. I hope it does stop, becose i want to record as many earthquakes as possible. I hope that my computer doesn't fail many time over the next years and months. Regards. -- Jón Frímann Jónsson http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: speaking about bad luck From: "Geoffrey" gmvoeth@........... Date: Sun, 2 Apr 2006 20:28:26 -0700 Hello Mr. Frimann; I find it interesting that you have the very same fears as myself. Time is on your side. If you miss an earthquake today you can be 100% sure there will be another tomorrow. Regards; gmvoeth ----- Original Message ----- From: "Jón Frímann" To: Sent: Sunday, April 02, 2006 8:12 PM Subject: Re: speaking about bad luck > Hi Ian and everybody else. > > I find it bad to miss a earthquake becose it has to happen the same day > that i need to work on my geophone or the computer. I have lost two > earthquakes so far, becose i was working on my geophone or becose of > hardware failure in the computer. > > I hope it does stop, becose i want to record as many earthquakes as > possible. I hope that my computer doesn't fail many time over the next > years and months. > > Regards. > -- > Jón Frímann Jónsson > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > 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: Unknown Arizona Earthquake From: "Geoffrey" gmvoeth@........... Date: Mon, 3 Apr 2006 02:55:59 -0700 Hello Anyone interested; Here is the data for what I believe to be an EQ here in Arizona but no reports seem to be made by the big guys on this one. If someone could associate this with an EQ here in AZ I would like to know. I might expect that military test that is upcoming in June to look something like this from Nevada. http://users.isp.com/gmvoethb293690/ArizonaEQ.zip The password for the zip file is: arizona all small letters. I think it to be about 1.8 degrees away but winquake says more like 2.1 degrees. That is from Apache Junction, AZ. Regards; gmvoeth __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: ChrisAtUpw@....... Date: Tue, 4 Apr 2006 12:53:39 EDT In a message dated 31/03/2006, jpopelish@........ writes: Is anyone planning on trying to capture this bump? http://www.military.com/NewsContent/0,13319,92910,00.html >> the spectacle of detonating a 700-ton (635-metric ton) explosive in the Nevada desert It might be helpful if the weights were correctly defined. There are metric tonnes, short tons and long tons, but there is no such animal as a 'metric ton'. >> James Tegnelia, head of the Defense Threat Reduction Agency, a Pentagon unit that is working on technical aspects of how to destroy deeply buried enemy weapons. There are already quite a few nuclear ground burst depressions at various test sites, which James could measure; Enewetak in the Marshall Islands, for instance. If James had read up the history of WW II, he might have heard about deep penetration 'Earthquake' bombs for destroying underground sites. This is the only effective way that was found to destroy a deeply buried installation. There are deep bunkers in Europe which were destroyed this way in WW II, but which could be studied. How about the installations in Iraq? I would be interested to know how the military intend to detonate this amount of AN/FO? What about the toxic by-products? Check which way the wind is blowing on the 2nd.... Regards, Chris Chapman
In a message dated 31/03/2006, jpopelish@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Is=20 anyone planning on trying to capture this=20 bump?
http://www.military.com/NewsContent/0,13319,92910,00.html<= /BLOCKQUOTE>
>>    the spectacle of detonating a 700-ton=20 (635-metric ton) explosive in the Nevada desert
 
    It might be helpful if the weights were correct= ly=20 defined. There are metric tonnes, short tons and long tons, but there i= s no=20 such animal as a 'metric ton'.
 
>>    James Tegnelia, head of the Defense Thr= eat=20 Reduction Agency, a Pentagon unit that is working on technical aspects of ho= w to=20 destroy deeply buried enemy weapons.
 
    There are already quite a few nuclear ground bu= rst=20 depressions at various test sites, which James could measure; Enewetak=20= in=20 the Marshall Islands, for instance.
    If James had read up the history of WW II, he m= ight=20 have heard about deep penetration 'Earthquake' bombs for destroying undergro= und=20 sites. This is the only effective way that was found to destroy a deepl= y=20 buried installation. There are deep bunkers in Europe which were destro= yed=20 this way in WW II, but which could be studied. How about the installations i= n=20 Iraq?
    I would be interested to know how the military=20 intend to detonate this amount of AN/FO? What about the toxic by-products? C= heck=20 which way the wind is blowing on the 2nd....
 
    Regards,
 
    Chris Chapman
Subject: Re: Man Made Quake From: ian ian@........... Date: Tue, 04 Apr 2006 18:03:10 +0100 the comparrison is deeply flawed. A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight. Ian. ChrisAtUpw@....... wrote: > In a message dated 31/03/2006, jpopelish@........ writes: > > Is anyone planning on trying to capture this bump? > http://www.military.com/NewsContent/0,13319,92910,00.html > > >> the spectacle of detonating a 700-ton (635-metric ton) explosive > in the Nevada desert > > It might be helpful if the weights were correctly defined. There > are metric tonnes, short tons and long tons, but there is no such > animal as a 'metric ton'. > > >> James Tegnelia, head of the Defense Threat Reduction Agency, a > Pentagon unit that is working on technical aspects of how to destroy > deeply buried enemy weapons. > > There are already quite a few nuclear ground burst depressions at > various test sites, which James could measure; Enewetak in the > Marshall Islands, for instance. > If James had read up the history of WW II, he might have heard > about deep penetration 'Earthquake' bombs for destroying underground > sites. This is the only effective way that was found to destroy a > deeply buried installation. There are deep bunkers in Europe which > were destroyed this way in WW II, but which could be studied. How > about the installations in Iraq? > I would be interested to know how the military intend to detonate > this amount of AN/FO? What about the toxic by-products? Check which > way the wind is blowing on the 2nd.... > > Regards, > > Chris Chapman the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force.  Someone screwed up significantly when we went metric.  It should have been Newtons or Kilo-Newtons for measuring weight.

Ian. 

ChrisAtUpw@....... wrote:
In a message dated 31/03/2006, jpopelish@........ writes:
Is anyone planning on trying to capture this bump?
http://www.military.com/NewsContent/0,13319,92910,00.html
>>    the spectacle of detonating a 700-ton (635-metric ton) explosive in the Nevada desert
 
    It might be helpful if the weights were correctly defined. There are metric tonnes, short tons and long tons, but there is no such animal as a 'metric ton'.
 
>>    James Tegnelia, head of the Defense Threat Reduction Agency, a Pentagon unit that is working on technical aspects of how to destroy deeply buried enemy weapons.
 
    There are already quite a few nuclear ground burst depressions at various test sites, which James could measure; Enewetak in the Marshall Islands, for instance.
    If James had read up the history of WW II, he might have heard about deep penetration 'Earthquake' bombs for destroying underground sites. This is the only effective way that was found to destroy a deeply buried installation. There are deep bunkers in Europe which were destroyed this way in WW II, but which could be studied. How about the installations in Iraq?
    I would be interested to know how the military intend to detonate this amount of AN/FO? What about the toxic by-products? Check which way the wind is blowing on the 2nd....
 
    Regards,
 
    Chris Chapman
Subject: Re: Man Made Quake From: ChrisAtUpw@....... Date: Tue, 4 Apr 2006 14:27:29 EDT In a message dated 04/04/2006, ian@........... writes: the comparrison is deeply flawed. A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight. Ian. Hi Ian, No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'? Regards, Chris Chapman
In a message dated 04/04/2006, ian@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>the=20 comparrison is deeply flawed.  A metric tonne is a unit of mass, a to= n is=20 a unit of force. Someone screwed up significantly when we went metric= .. It=20 should have been Newtons or Kilo-Newtons for measuring=20 weight.

Ian. 
Hi Ian,
 
    No, it should not be defined as the force. If i= t=20 were, the actual quantity (mass) would vary from place to place. The ton in=20 commerce is also mass. Going metric wasn't a 'screw up'?
 
    Regards,
 
    Chris Chapman
Subject: Re: Man Made Quake From: ian ian@........... Date: Tue, 04 Apr 2006 19:45:01 +0100 at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it! Sigh. :-) Ian ChrisAtUpw@....... wrote: > In a message dated 04/04/2006, ian@........... writes: > > the comparrison is deeply flawed. A metric tonne is a unit of > mass, a ton is a unit of force. Someone screwed up significantly > when we went metric. It should have been Newtons or Kilo-Newtons > for measuring weight. > > Ian. > > Hi Ian, > > No, it should not be defined as the force. If it were, the actual > quantity (mass) would vary from place to place. The ton in commerce is > also mass. Going metric wasn't a 'screw up'? > > Regards, > > Chris Chapman at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it!

Sigh.

:-)

Ian


ChrisAtUpw@....... wrote:
In a message dated 04/04/2006, ian@........... writes:
the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight.

Ian. 
Hi Ian,
 
    No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'?
 
    Regards,
 
    Chris Chapman
Subject: Re: Man Made Quake From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Tue, 04 Apr 2006 19:03:57 +0000 Hi all At any rate, there is an answer. Here it is, http://en.wikipedia.org/wiki/Kilo Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: ian ian@........... Date: Tue, 04 Apr 2006 20:16:48 +0100 Hi, you probably meant: http://en.wikipedia.org/wiki/Kilogram Ian Jón Frímann wrote: >Hi all > >At any rate, there is an answer. Here it is, >http://en.wikipedia.org/wiki/Kilo > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Divine Strake -- Man Made Quake From: "Timothy Carpenter" geodynamics@....... Date: Tue, 4 Apr 2006 16:16:56 -0400 Folks, I've noted with amusement the bantering about weights and measures. But = I'm not at all amused about the upcoming "event" and its underlying purpose. = I'd suggest a quiet-time reading of: "Nuclear Bunker Buster Bombs" by = Michael Levy, Scientific American, August, 2004. http://www.sciamdigital.com/gsp_qpdf.cfm?ISSUEID_CHAR=3DA4AD4ADB-2B35-221= B-699 D1485A73879AA&ARTICLEID_CHAR=3DA4C0C473-2B35-221B-675DA971076806AD Then consider the 700-tons of ANFO proposed for the "Divine Strake" test against the yield (and weight) of the following: http://www.brook.edu/FP/projects/nucwcost/madm.htm I don't care what your politics may be, I simply don't trust ANY administration with deployment of this type of a weapon -- particularly = when they preface the name of the test with "Divine" -- talk about holy wars! Regards, -Tim- Timothy Carpenter -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of ian Sent: Tuesday, April 04, 2006 3:17 PM To: psn-l@.............. Subject: Re: Man Made Quake Hi, you probably meant: http://en.wikipedia.org/wiki/Kilogram Ian J=F3n Fr=EDmann wrote: >Hi all > >At any rate, there is an answer. Here it is, >http://en.wikipedia.org/wiki/Kilo > >Regards. > =20 > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Divine Strake -- Man Made Quake From: apsn apsn@........... Date: Tue, 04 Apr 2006 12:56:39 -0800 Tim, I subscribe to the Public Seismic Network=20 listserver to learn what others are doing with=20 amateur seismology and to help out when I can. I DO NOT subscribe to the list to hear personal=20 opinions concerning politics, disarmament, or religion. I think your comments are inappropriate for this=20 listserver. There's plenty of other lists where=20 you can express your opinions on such topics. I=20 suggest you post comments to them. Regards, Bob Hammond http://apsn.awcable.com At 08:27 AM 4/4/2006, you wrote: >Folks, > >I've noted with amusement the bantering about weights and measures. But I'm >not at all amused about the upcoming "event" and its underlying purpose.= I'd >suggest a quiet-time reading of: "Nuclear Bunker Buster Bombs" by Michael >Levy, Scientific American, August, 2004. > >http://www.sciamdigital.com/gsp_qpdf.cfm?ISSUEID_CHAR=3DA4AD4ADB-2B35-221B-= 699 >D1485A73879AA&ARTICLEID_CHAR=3DA4C0C473-2B35-221B-675DA971076806AD > >Then consider the 700-tons of ANFO proposed for the "Divine Strake" test >against the yield (and weight) of the following: > >http://www.brook.edu/FP/projects/nucwcost/madm.htm > >I don't care what your politics may be, I simply don't trust ANY >administration with deployment of this type of a weapon -- particularly= when >they preface the name of the test with "Divine" -- talk about holy wars! > >Regards, > >-Tim- > >Timothy Carpenter > > >-----Original Message----- >From: psn-l-request@.............. [mailto:psn-l-request@............... On >Behalf Of ian >Sent: Tuesday, April 04, 2006 3:17 PM >To: psn-l@.............. >Subject: Re: Man Made Quake > >Hi, > >you probably meant: http://en.wikipedia.org/wiki/Kilogram > >Ian > >J=F3n Fr=EDmann wrote: > > >Hi all > > > >At any rate, there is an answer. Here it is, > >http://en.wikipedia.org/wiki/Kilo > > > >Regards. > > > > >__________________________________________________________ > >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: Divine Strake -- Man Made Quake From: AHrubetz@....... Date: Tue, 4 Apr 2006 17:00:21 EDT I agree 100% with Bob Hammond. I am not interested in anyone's personal political opinions posted on PSN. Al Hrubetz
I agree 100% with Bob Hammond.  I am not interested in&nbs= p;anyone's personal political opinions posted on PSN.
    Al Hrubetz
Subject: Winsdr remote station test From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Tue, 04 Apr 2006 23:01:10 +0000 Hi all I want to know if somebody is willing to test with me the remote option in winsdr, i want to test both server and the client option. I have a fast adsl, so speed is not the problem on my end. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Divine Strake -- Man Made Quake From: ChrisAtUpw@....... Date: Tue, 4 Apr 2006 22:40:54 EDT In a message dated 04/04/2006, geodynamics@....... writes: I'm not at all amused about the upcoming "event" Hi Tim, Thanks for the useful reference information. It will be most interesting to observe what magnitude of quake is actually produced by the known mass of explosive and how the 'signature' varies with distance and soil type. And if anything does go wrong, you will just get some well distributed airbourne fertiliser, but do avoid the downwind plume. It could have fine silicate material (carcinogenic) and N2O. Regards, Chris Chapman
In a message dated 04/04/2006, geodynamics@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I'm not=20 at all amused about the upcoming "event"
Hi Tim,
 
    Thanks for the useful reference information. It= =20 will be most interesting to observe what magnitude of quake is actually prod= uced=20 by the known mass of explosive and how the 'signature' varies wi= th=20 distance and soil type.
    And if anything does go wrong, you will just ge= t=20 some well distributed airbourne fertiliser, but do avoid the downwind plume.= It=20 could have fine silicate material (carcinogenic) and N2O.
 
    Regards,
 
    Chris Chapman
Subject: Glacier-melting induced quakes From: George Bush ke6pxp@....... Date: Wed, 05 Apr 2006 09:47:25 -0700 J=F3n Fr=EDmann- I was wondering if you have any Glaciers nearby? I just read a note in the New Scientist of 1 April 2006 p20 that referenced an article in Science (vol311, p 1756). The note said, in part: "Goran Ekstrom, a seismologist at Harvard University, says the rapid melting [of glaciers] causes water to collect under the ice faster than it can drain away. This makes the glaciers slip faster into the sea, which causes more quakes. Ekstrom discovered glacial quakes three years ago after noticing that some signals picked up by seismic monitors contained fewer high-frequency waves than is normal for an earthquake. He traced their source to slips within ice sheets. Most were in Greenland, but they also occur in Alaska and Antartica." Maybe you can detect some of these glacier quakes? George Bush Sea Ranch, CA, USA 38.73775N, 123.48882W __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacier-melting induced quakes From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 05 Apr 2006 18:22:29 +0000 Hi George The closest glaciers to me are Langjökull at distance of ~80 Km and Hofsjökull at distance of ~100 km. Hofsjökull has producsted glacier quakes, but i haven't been able to detect them. Mostly becose those type of quakes have little energy and they need water to drive them. But both of those glaciers are relative small, but Hofsjökull is more deeper, but max depth there is ~650 meters. Langjökull is not that deep, i don't know exacly how deep, but i think it is no more then ~400 meters. The only place that i know of that produces glacer earthquakes on regular basis is Vatnajökull, then in accurance with flood from under the glacer it self. The glacer quakes are more common in the summer time then in the winter time. Becose of a distance i don't pick those up, but i usally don't detect earthquakes in Vatnajökull zone unless they are above ~3.0Ml in size. The glacer quakes that happen are however mesured by the Icelandic Met office, besides flood starting glacer quakes or icequakes as they are called in the Icelandic Met Office is rain the put the glacer in movement and creates icequakes, as can be seen here http://hraun.vedur.is/ja/viku/2005/vika_36/Laufbali_rainfall_icequakes.JPG on this nice graph from the Icelandic Met Office. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Glacier-melting induced quakes From: "Kareem at HeyJooJoo" system98765@............. Date: Wed, 5 Apr 2006 17:24:40 -0700 What magnitudes are these glacier quakes generally reaching?=20 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of George Bush Sent: Wednesday, April 05, 2006 9:47 AM To: psn-l@.............. Subject: Glacier-melting induced quakes J=F3n Fr=EDmann- I was wondering if you have any Glaciers nearby? I just read a note in = the New Scientist of 1 April 2006 p20 that referenced an article in Science (vol311, p 1756). The note said, in part: "Goran Ekstrom, a seismologist at Harvard University, says the rapid = melting [of glaciers] causes water to collect under the ice faster than it can = drain away. This makes the glaciers slip faster into the sea, which causes = more quakes. Ekstrom discovered glacial quakes three years ago after noticing that some signals picked up by seismic monitors contained fewer high-frequency waves than is normal for an earthquake. He traced their source to slips within ice sheets. Most were in Greenland, but they also occur in Alaska and Antartica." Maybe you can detect some of these glacier quakes? George Bush Sea Ranch, CA, USA 38.73775N, 123.48882W __________________________________________________________ Public Seismic Network Mailing List (PSN-L) http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Glacier-melting induced quakes From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Thu, 06 Apr 2006 00:32:28 +0000 Hi Kareem The size of the glacier earthquakes are from ~0.0Ml to ~2.5Ml, they don't get any bigger then that since the ice cannot hold alot of energy. There is one small glacier north-west of me (i forgot it in the other email), but becose of a distance of a ~70 km i don't expect to detect earthquakes from that glacier. But i will see what happens next summer. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: PhD positions in geophysics in Iceland From: "Erich Kern" efkern@............. Date: Thu, 6 Apr 2006 17:34:49 -0700 *************************************** PhD positions in geophysics in Iceland *************************************** From: Ţóra Árnadóttir The Institute of Earth Sciences, University of Iceland, is a new research institute within the University of Iceland that combines the Universitie´s strengths in the Earth sciences. Twenty seven professors and senior researchers at the institute and about twenty other staff work within most fields of Earth science in a dynamic and collaborative research environment. Currently, there are about 10 PhD students at the institute of five different nationalities and their numbers are rising. The Institute of Earth Sciences has three vacant positions for PhD students in geophysics that are tied to funded projects. They are: Structure of the Iceland crust from ambient seismic noise tomography: The purpose of the project is to perform tomographic analyses of the Iceland crust based on seismic wave speed. The analysis method is novel and is based on surface waves that are isolated in correlograms of microseismic noise generated by wave motions on the ocean around Iceland. The student needs strength in computer programming and data analysis. He will gain experience with data ackquisition, time-series analyses, surface-wave analyses, inverse theory and the theoretical description of microseismic noise (Contact Dr. Ólafur Guđmundsson for further details). Sea-level changes around Iceland: The objectives of the project are to assemble all available tide gauge and satellite data, apply appropriate corrections, and interpret in terms of global sealevel change, crustal movements, ocean currents and conditions. (Contact Prof. Páll Einarsson for further details) High-rate continuous GPS observations in Iceland: The goal of this project is to introduce a new type of crustal deformation monitoring in Iceland by continuous GPS measurements with a sampling rate of 1 second in selected areas. The high sampling rate enables us to study both dynamic as well as transient and slower rate deformation processes related to earthquakes, volcanic activity and plate spreading in Iceland. The project is a collaborative effort between Icelandic scientists and co-workers in Europe, US and Japan, and includes three other PhD positions at different universities. The student needs to have a strong background in computer programming and data analysis. He will gain experience in GPS field work, data analysis, and deformation modelling. Further information on the project can be found at: http://www.norvol.hi.is/~thora/ondvegi.html or by contacting Dr. Thóra Árnadóttir Applications must include a CV, a copy of university diplomas with grade information and two references. Applicants must specify which projects interest them most and send the application to: Geophysics PHD01, Institute of Earth Sciences, Askja, Sturlugata 7, 101 Reykjavík, Iceland. The application deadline is on the 1st of June, 2006. Those that are interested are encouraged to contact Ólafur Guđmundsson (olafurg@....... Páll Einarsson (palli@.............. or Thóra Árnadóttir (thora1@...... for more information about the projects and other information. ============================================================== __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Remote connecton to my station over the internet From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 07 Apr 2006 02:48:04 +0000 Hi all Those how have intrest in connecting to my station over the internet with winsdr to get raw data from it, can now just drop me a email for the ip and the connection port and other important info. I don't know how many connection my adsl can handle, i am just going to have to test that limit. I have 768kbps upload speed on my adsl. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PhD positions in geophysics in Iceland From: "Geoffrey" gmvoeth@........... Date: Thu, 6 Apr 2006 18:10:13 -0700 I do not see any saleries or wages or compensations or benefits or contracts listed. Why do they always leave such important information out of the picture ? Regards; gmvoeth ----- Original Message ----- From: "Erich Kern" To: "Tina" ; "WATSON" ; "PSN-L Mailing List" Sent: Thursday, April 06, 2006 5:34 PM Subject: PhD positions in geophysics in Iceland __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PhD positions in geophysics in Iceland From: "Erich Kern" efkern@............. Date: Thu, 6 Apr 2006 21:30:35 -0700 That's so you'll contact them if you're interested. Erich ----- Original Message ----- From: "Geoffrey" To: Sent: Thursday, April 06, 2006 6:10 PM Subject: Re: PhD positions in geophysics in Iceland I do not see any saleries or wages or compensations or benefits or contracts listed. Why do they always leave such important information out of the picture ? Regards; gmvoeth ----- Original Message ----- From: "Erich Kern" To: "Tina" ; "WATSON" ; "PSN-L Mailing List" Sent: Thursday, April 06, 2006 5:34 PM Subject: PhD positions in geophysics in Iceland __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Recording a teleseismic event, recording time From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 07 Apr 2006 22:30:17 +0000 Hi all Larry Cochrane was kind enugh to allow me to monitor few of his seismontors over the internet, he is currently monitoring my station over the internet in return. Most of Larry stations are teleseismic and therefor record a long distance events. I need a suggestion for time period to record such events, then i mean 60 min, 90 min or longer or shorter. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Recording a teleseismic event, recording time From: "Geoffrey" gmvoeth@........... Date: Sat, 8 Apr 2006 03:46:16 -0700 Hello Mr. Frimann; If you have a modulo recorder with some kind of alarm you only need about 30 minutes of histoey to capture almost any earthquake out there. But the very big earthquakes will go on for an hour or more in that case you might develop several files all relating to the same event but if you capture only the P,S,L waves that is all you want to do. Not to watch every undulation unless you are making somekind of tomography as part of a large homogenous academic system. This has been learned by me through experience and not by formal education. Regards; gmvoeth ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Friday, April 07, 2006 3:30 PM Subject: Recording a teleseismic event, recording time __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Recording a teleseismic event, recording time From: ChrisAtUpw@....... Date: Sat, 8 Apr 2006 07:05:50 EDT Hi Jon, If you go to _http://neic.usgs.gov/neis/travel_times/_ (http://neic.usgs.gov/neis/travel_times/) you can download travel tiem P-S interval graphs. These are average times, but the should be quite accurate. Regards, Chris Chapman
Hi Jon,
 
    If you go to http://neic.usgs.gov/neis/t= ravel_times/ you=20 can download travel tiem P-S interval graphs. These are average times, but t= he=20 should be quite accurate.
 
    Regards,
 
    Chris Chapman
 Subject: Infrasound revisited From: "Arie Verveer" greensky@.............. Date: Sat, 08 Apr 2006 22:15:33 +0800 Hi all, This may be of interest. It's an article dealing with the electronics of infrasound detection using simple (cheap) electret condenser microphones. Worth a read: http://earth.unh.edu/johnson/MICROPHONES/ISLA14.pdf http://earth.unh.edu/johnson/MICROPHONES/J4.pdf While on holidays I plan to construct this device. It will be my third sensor dealing with infrasound. You never know, one might pick up the infrasonic signature of an earthquake, big volcanic eruption ,fireball or an elephant ! A previous sensor certainly picked up fireballs (Meteors). The electret microphones were purchased on "ebay" as a 100 microphones for $99.00 The sellers apparently has 70,000 of these, so I'm sure a new ebay item will appear soon. Anyhow the ebay search line is: Panasonic Electret Condenser Microphone WM-034DM The Sellars web address: Hi-Tech Enterprises, Inc. http://www.videoequipment.com (Note they are a discontinued line but if you have 100 of them, they never will be !) You can download the data on these WM-034 microphones from the "Panasonic" site at: http://www.panasonic.com/industrial/components/audio/aud_mic.htm Google Search Strings: J4 Microphones Popo Microphones infrasonic Microphones infrasound Prototype for an Expendable Infrasound Cheers Arie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Infrasound revisited From: "Geoffrey" gmvoeth@........... Date: Sat, 8 Apr 2006 08:08:21 -0700 Hello: If you really want to study meteors then use a CW radar approach. Make yourself a tunable 3 element YAGI-UDA antenna and feed it via a 50 ohm coax into the front end of a car radio such as a pioneer with a super tuner. Then you can have fun DXing FM radio stations from 1000 miles away using the ion trails left by meteors. It is most fun to do if you have a current radio guide and do this during a meteor shower. But you must have some empty radio channels or you are wasting your time. You will find best results from stations transmitting 100Kw or more ERP. You got to put the antenna on a pole 10 feet tall or so that you can use its directional qualities. The signal will appear strongest from the actual direction of the transmitter. The meteors will leave an expanding ion trail behind them you will see the meteor come in across the sky and a second or so later after the trail has expanded forming a kind of radio mirror in the sky you will hear the various stations you can rotate your antenna to find. As the meteor trail expands you might hear a kind of stuttering that I believe is caused by some kind of interference pattern. On really strong reflections you might see the stereo light come on. I can see the potential for long distance over the horizon communications using this technique but you need to use short burst transmissions and some kind of detector to let the transmitter know that conditions are right for this kind of communications. You must keep a big city behind you or you will be swamped by all kinds of RFI. I know this is getting off the EQ subject but just like watching EQ this thing is Amateur and it can be fun trying to ID the distant radio stations you listen to. Occasionally you might get special conditions which allow you to hear distant stations for 20 or 30 minutes which usually happen at sundown or sunrise. Regards: gmvoeth ----- Original Message ----- From: "Arie Verveer" To: Sent: Saturday, April 08, 2006 7:15 AM Subject: Infrasound revisited __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Infrasound revisited From: ChrisAtUpw@....... Date: Sat, 8 Apr 2006 19:16:02 EDT In a message dated 08/04/2006, greensky@.............. writes: This may be of interest. It's an article dealing with the electronics of infrasound detection using simple (cheap) electret condenser microphones. http://earth.unh.edu/johnson/MICROPHONES/ISLA14.pdf http://earth.unh.edu/johnson/MICROPHONES/J4.pdf Hi Arie, Also have a look at _http://earth.unh.edu/johnson/MICROPHONES/ISLA4.pdf_ (http://earth.unh.edu/johnson/MICROPHONES/ISLA4.pdf) I think that this probably gives more realistic measurements. While on holidays I plan to construct this device. It will be my third sensor dealing with infrasound. Good luck! The problems with these microphones is that they don't really go to low enough frequencies and they do drift with temperature. The circuits described could benefit from a three or four pole low pass cut-off filter. You can get greatly extended LF range and reduced noise using a 2" electret piezo speaker as the sensor. They have a capacity of ~65 nF, so with a 47 M Ohm input impedance, you can get a Tc of 3 sec, corresponding to a period of 19 sec, 0.05Hz. The straight sided 1L "food" flasks can be modified as low temperature drift capacities. I use 100 M Ohm to get to 40 sec period with an OPA604 opamp. It is an advantage to fill the capacity with the lowest density polyurethane foam. This ensures a near isothermal pressure response as opposed to an adiabatic / slump response and gives about 40% more output. The pressure / temperature relaxation time constant of this system seems to be about 0.1 sec. The thermal drift can be reduced if necessary by adding candle wax to the inside of the flask to increase the 'thermal mass'. The thermal time constant of an empty flask for ambient temperature changes may be about 1/2 hr. You can also use a screw top glass jar with a restriction tube as a simple series low pass RC input filter to limit the pulse / noise response. You need to use a ~constant disk temperature to avoid LARGE voltage drifts. As with all sensitive LF microphones, you do need to limit the wind noise, preferably with a loop of porous irrigation hose, maybe 10 to 30 m diameter, with solid cross connecting tubes to the sensor in the centre. Panasonic Electret Condenser Microphone WM-034DM The Sellers web address: Hi-Tech Enterprises, Inc. http://www.videoequipment.com (Note they are a discontinued line) You can download the data on these WM-034 microphones from: _http://www.panasonic.com/industrial/components/audio/aud_mic.htm_ (http://www.panasonic.com/industrial/components/audio/aud_mic.htm) If you buy the CURRENT Panasoic WM61A, you will get a higher sensitivity. I suspect that the VLF response is likely to be similar. You can also use these for intruder detection. You can't open a window or a door without getting quite a large signal. There is a comprehensive web page giving details of several types of infrasonic sensor at _http://earth.unh.edu/johnson/MICROPHONES/microphone_list.html_ (http://earth.unh.edu/johnson/MICROPHONES/microphone_list.html) This is worth serious attention for anyone interested in infrasound. Regards, Chris Chapman
In a message dated 08/04/2006, greensky@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>This may=20 be of interest. It's an article dealing with the electronics of infrasound= =20 detection using simple (cheap) electret condenser microphones.
 &n= bsp;=20 http://earth.unh.edu/johnson/MICROPHONES/ISLA14.pdf
  =20 http://earth.unh.edu/johnson/MICROPHONES/J4.pdf
Hi Arie,
 
    Also have a look at http://earth.unh= ..edu/johnson/MICROPHONES/ISLA4.pdf I=20 think that this probably gives more realistic measurements. 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>While on=20 holidays I plan to construct this device. It
will be my third sensor=20 dealing with infrasound.
    Good luck!
    The problems with these microphones is tha= t=20 they don't really go to low enough frequencies and they do drift with=20 temperature.
    The circuits described could benefit from a thr= ee=20 or four pole low pass cut-off filter.
 
    You can get greatly extended LF range and reduc= ed=20 noise using a 2" electret piezo speaker as the sensor. They have a capa= city=20 of ~65 nF, so with a 47 M Ohm input impedance, you can get a Tc of 3 se= c,=20 corresponding to a period of 19 sec, 0.05Hz.
    The straight sided 1L "food" flasks can be= =20 modified as low temperature drift capacities. I use 100 M Ohm to g= et=20 to 40 sec period with an OPA604 opamp.
    It is an advantage to fill the capacity with th= e=20 lowest density polyurethane foam. This ensures a near isothermal=20 pressure response as opposed to an adiabatic / slump response and gives= =20 about 40% more output. The pressure / temperature relaxation time constant o= f=20 this system seems to be about 0.1 sec.
    The thermal drift can be reduced if necessary b= y=20 adding candle wax to the inside of the flask to increase the 'thermal mass'.= The=20 thermal time constant of an empty flask for ambient=20 temperature changes may be about 1/2 hr.
    You can also use a screw top glass jar with a=20 restriction tube as a simple series low pass RC input filter to limit the pu= lse=20 / noise response.
    You need to use a ~constant=20 disk temperature to avoid LARGE voltage drifts. 
    As with all sensitive LF microphones, you do ne= ed=20 to limit the wind noise, preferably with a loop of porous irrigation hose, m= aybe=20 10 to 30 m diameter, with solid cross connecting tubes to the sens= or=20 in the centre.
 
Panasonic Electret Condenser Microphone WM-034DM
   Th= e=20 Sellers web address:
   Hi-Tech Enterprises, Inc.=20 http://www.videoequipment.com

(Note they are a discontinued line)
= You=20 can download the data on these WM-034 microphones from:
ht= tp://www.panasonic.com/industrial/components/audio/aud_mic.htm
 
    If you buy the CURRENT Panasoic WM61A, you will= get=20 a higher sensitivity. I suspect that the VLF response is likely to be= =20 similar. You can also use these for intruder detection. You can't open a win= dow=20 or a door without getting quite a large signal.
 
    There is a comprehensive web page giving detail= s of=20 several types of infrasonic sensor at http:= //earth.unh.edu/johnson/MICROPHONES/microphone_list.html
    This is worth serious attention for anyone=20 interested in infrasound.
 
    Regards,
 
    Chris Chapman
Subject: April starts quiet From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 09 Apr 2006 06:35:57 +0000 Hi all Since i got my geophone to record earthquakes there has been hig and low top in earthquake activiti. To this day Febuary has been the most busy one, with 90 files (all three axis, z,n-s,e-w). Mars only had 69 files. January only had 12 files, but i lost many event becose of a wrong configuration at the time. So far i have only detected one event in April (3 files), bad weather have limited my options in detecting earthquakes past two weeks, but i hope that most of the winter storm season is over. I have lost two event becose the geohone was offline at the time. But it has been my experiance that following this type of quiet time, there is going to come a time with alot of earthquakes, problay a time simluar to that one in Febuary. In other news, i am going to update my webpage with the tremor plots soon. The webpage is going to be split up in two parts this time. One Icelandic and other English. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: Barry Lotz barry_lotz@............. Date: Mon, 10 Apr 2006 06:31:03 -0700 (PDT) Hi All If I remember my physics, mass does not vary with location (unless you are traveling very fast) but force does ( f=m*a) . the earths acceleration does vary with location. regards Barry ian wrote: at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it! Sigh. :-) Ian ChrisAtUpw@....... wrote: In a message dated 04/04/2006, ian@........... writes: the comparrison is deeply flawed. A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight. Ian. Hi Ian, No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'? Regards, Chris Chapman
Hi All
 If I remember my physics, mass does not vary with location (unless you are traveling very fast) but force does ( f=m*a) . the earths acceleration does vary with location.
regards
Barry


ian <ian@...........> wrote:
at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it!

Sigh.

:-)

Ian


ChrisAtUpw@....... wrote:
In a message dated 04/04/2006, ian@iasmith.com writes:
the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight.

Ian. 
Hi Ian,
 
    No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'?
 
    Regards,
 
    Chris Chapman

Subject: Re: Man Made Quake From: ian ian@........... Date: Mon, 10 Apr 2006 16:11:58 +0100 yes, mass is a constant which is the nice thing about it. Sorry to bring this discussion here, apologies in advance. The problem is that mass and weight are different concepts. When we buy a quantity of goods, like flour for instance, we put the flour on a weighing machine, which measures the weight but, under the metric system, we quote the weight in units of mass (Kg). Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring machine to Panama and measure out another 10 Kg, we will find that the two 10 Kg bags of flour are different (by a tiny amount). This takes us back to the original (correct) premise that mass does not vary and so there is something wrong with our experiment. The something wrong is that we used a weighing machine (instead of a "massing" machine) and implicitly applied a constant to convert the weight into mass. The constant is the thing that varies with where you are on the Earth and mainly consists of the acceleration due to the Earth's gravity, minus the centrifugal force caused by the Earth's spin. Both contributions vary around the globe. Again, apologies for the non-quaky topic. Ian Barry Lotz wrote: > Hi All > If I remember my physics, mass does not vary with location (unless > you are traveling very fast) but force does ( f=m*a) . the earths > acceleration does vary with location. > regards > Barry > > > ian wrote: > > at the risk of religious wars(!), the "kilo" is subject to > variation from place to place because we use a weighing machine to > measure it! > > Sigh. > > :-) > > Ian > > > ChrisAtUpw@....... wrote: > >> In a message dated 04/04/2006, ian@........... writes: >> >> the comparrison is deeply flawed. A metric tonne is a unit >> of mass, a ton is a unit of force. Someone screwed up >> significantly when we went metric. It should have been >> Newtons or Kilo-Newtons for measuring weight. >> >> Ian. >> >> Hi Ian, >> >> No, it should not be defined as the force. If it were, the >> actual quantity (mass) would vary from place to place. The ton in >> commerce is also mass. Going metric wasn't a 'screw up'? >> >> Regards, >> >> Chris Chapman > > yes, mass is a constant which is the nice thing about it. 

Sorry to bring this discussion here, apologies in advance.

The problem is that mass and weight are different concepts.  When we buy a quantity of goods, like flour for instance, we put the flour on a weighing machine, which measures the weight but, under the metric system, we quote the weight in units of mass (Kg). 

Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring machine to Panama and measure out another 10 Kg, we will find that the two 10 Kg bags of flour are different (by a tiny amount).  This takes us back to the original (correct) premise that mass does not vary and so there is something wrong with our experiment. 

The something wrong is that we used a weighing machine (instead of a "massing" machine) and implicitly applied a constant to convert the weight into mass.  The constant is the thing that varies with where you are on the Earth and mainly consists of the acceleration due to the Earth's gravity, minus the centrifugal force caused by the Earth's spin.  Both contributions vary around the globe.

Again, apologies for the non-quaky topic.

Ian

Barry Lotz wrote:
Hi All
 If I remember my physics, mass does not vary with location (unless you are traveling very fast) but force does ( f=m*a) . the earths acceleration does vary with location.
regards
Barry


ian <ian@...........> wrote:
at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it!

Sigh.

:-)

Ian


ChrisAtUpw@....... wrote:
In a message dated 04/04/2006, ian@........... writes:
the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight.

Ian. 
Hi Ian,
 
    No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'?
 
    Regards,
 
    Chris Chapman

Subject: Re: Man Made Quake From: "James Hannon" jmhannon@......... Date: Mon, 10 Apr 2006 10:19:29 -0500 There are actually two types of "weighing machines" scales. One uses springs and actually measures force. The other is a balance which compares one mass against another. This type of scale will be accurate in measuring mass as long as there is any gravity at all. ---------- Original Message ---------------------------------- From: ian Reply-To: psn-l@.............. Date: Mon, 10 Apr 2006 16:11:58 +0100 >yes, mass is a constant which is the nice thing about it. > >Sorry to bring this discussion here, apologies in advance. > >The problem is that mass and weight are different concepts. When we buy >a quantity of goods, like flour for instance, we put the flour on a >weighing machine, which measures the weight but, under the metric >system, we quote the weight in units of mass (Kg). > >Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring >machine to Panama and measure out another 10 Kg, we will find that the >two 10 Kg bags of flour are different (by a tiny amount). This takes us >back to the original (correct) premise that mass does not vary and so >there is something wrong with our experiment. > >The something wrong is that we used a weighing machine (instead of a >"massing" machine) and implicitly applied a constant to convert the >weight into mass. The constant is the thing that varies with where you >are on the Earth and mainly consists of the acceleration due to the >Earth's gravity, minus the centrifugal force caused by the Earth's >spin. Both contributions vary around the globe. > >Again, apologies for the non-quaky topic. > >Ian > >Barry Lotz wrote: > >> Hi All >> If I remember my physics, mass does not vary with location (unless >> you are traveling very fast) but force does ( f=m*a) . the earths >> acceleration does vary with location. >> regards >> Barry >> >> >> ian wrote: >> >> at the risk of religious wars(!), the "kilo" is subject to >> variation from place to place because we use a weighing machine to >> measure it! >> >> Sigh. >> >> :-) >> >> Ian >> >> >> ChrisAtUpw@....... wrote: >> >>> In a message dated 04/04/2006, ian@........... writes: >>> >>> the comparrison is deeply flawed. A metric tonne is a unit >>> of mass, a ton is a unit of force. Someone screwed up >>> significantly when we went metric. It should have been >>> Newtons or Kilo-Newtons for measuring weight. >>> >>> Ian. >>> >>> Hi Ian, >>> >>> No, it should not be defined as the force. If it were, the >>> actual quantity (mass) would vary from place to place. The ton in >>> commerce is also mass. Going metric wasn't a 'screw up'? >>> >>> Regards, >>> >>> Chris Chapman >> >> > > -- Jim Hannon http://www.fmtcs.com/web/jmhannon/ 42,11.90N,91,39.26W WB0TXL -- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: ChrisAtUpw@....... Date: Mon, 10 Apr 2006 11:24:17 EDT In a message dated 10/04/2006, ian@........... writes: When we buy a quantity of goods, like flour for instance, we put the flour on a weighing machine, which measures the weight but, under the metric system, we quote the weight in units of mass (Kg). Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring machine to Panama and measure out another 10 Kg, we will find that the two 10 Kg bags of flour are different (by a tiny amount). Hi Ian, Only if you use a force balance. If you use balance scales with weights, or a steelyard, you get no variation, because they measure mass. Regards, Chris Chapman
In a message dated 10/04/2006, ian@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>When we=20 buy a quantity of goods, like flour for instance, we put the flour on a=20 weighing machine, which measures the weight but, under the metric system,=20= we=20 quote the weight in units of mass (Kg). 

Now if we buy 10 Kg=20= of=20 flour in Reykjavik then take it and the measuring machine to Panama and=20 measure out another 10 Kg, we will find that the two 10 Kg bags of flour a= re=20 different (by a tiny amount). 
Hi Ian,
 
    Only if you use a force balance. If you use bal= ance=20 scales with weights, or a steelyard, you get no variation, because they meas= ure=20 mass.
 
    Regards,
 
    Chris Chapman
Subject: Re: Man Made Quake From: ian ian@........... Date: Mon, 10 Apr 2006 16:25:44 +0100 agreed. The spring type of weighing machine though is, I believe, in the majority given their advantage of not needing weights. My last email assumed the use of the spring type weighing machines. Ian James Hannon wrote: >There are actually two types of "weighing machines" scales. One uses springs and actually measures force. The other is a balance which compares one mass against another. This type of scale will be accurate in measuring mass as long as there is any gravity at all. > >---------- Original Message ---------------------------------- >From: ian >Reply-To: psn-l@.............. >Date: Mon, 10 Apr 2006 16:11:58 +0100 > > > >>yes, mass is a constant which is the nice thing about it. >> >>Sorry to bring this discussion here, apologies in advance. >> >>The problem is that mass and weight are different concepts. When we buy >>a quantity of goods, like flour for instance, we put the flour on a >>weighing machine, which measures the weight but, under the metric >>system, we quote the weight in units of mass (Kg). >> >>Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring >>machine to Panama and measure out another 10 Kg, we will find that the >>two 10 Kg bags of flour are different (by a tiny amount). This takes us >>back to the original (correct) premise that mass does not vary and so >>there is something wrong with our experiment. >> >>The something wrong is that we used a weighing machine (instead of a >>"massing" machine) and implicitly applied a constant to convert the >>weight into mass. The constant is the thing that varies with where you >>are on the Earth and mainly consists of the acceleration due to the >>Earth's gravity, minus the centrifugal force caused by the Earth's >>spin. Both contributions vary around the globe. >> >>Again, apologies for the non-quaky topic. >> >>Ian >> >>Barry Lotz wrote: >> >> >> >>>Hi All >>> If I remember my physics, mass does not vary with location (unless >>>you are traveling very fast) but force does ( f=m*a) . the earths >>>acceleration does vary with location. >>>regards >>>Barry >>> >>> >>>ian wrote: >>> >>> at the risk of religious wars(!), the "kilo" is subject to >>> variation from place to place because we use a weighing machine to >>> measure it! >>> >>> Sigh. >>> >>> :-) >>> >>> Ian >>> >>> >>> ChrisAtUpw@....... wrote: >>> >>> >>> >>>> In a message dated 04/04/2006, ian@........... writes: >>>> >>>> the comparrison is deeply flawed. A metric tonne is a unit >>>> of mass, a ton is a unit of force. Someone screwed up >>>> significantly when we went metric. It should have been >>>> Newtons or Kilo-Newtons for measuring weight. >>>> >>>> Ian. >>>> >>>> Hi Ian, >>>> >>>> No, it should not be defined as the force. If it were, the >>>> actual quantity (mass) would vary from place to place. The ton in >>>> commerce is also mass. Going metric wasn't a 'screw up'? >>>> >>>> Regards, >>>> >>>> Chris Chapman >>>> >>>> >>> >>> >> >> > >-- >Jim Hannon >http://www.fmtcs.com/web/jmhannon/ >42,11.90N,91,39.26W >WB0TXL >-- >__________________________________________________________ > >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. > > > > agreed.  The spring type of weighing machine though is, I believe, in the majority given their advantage of not needing weights.  My last email assumed the use of the spring type weighing machines.

Ian

James Hannon wrote:
There are actually two types of "weighing machines" scales. One uses springs and actually measures force. The other is a balance which compares one mass against another. This type of scale will be accurate in measuring mass as long as there is any gravity at all. 

---------- Original Message ----------------------------------
From: ian <ian@...........>
Reply-To: psn-l@..............
Date:  Mon, 10 Apr 2006 16:11:58 +0100

  
yes, mass is a constant which is the nice thing about it. 

Sorry to bring this discussion here, apologies in advance.

The problem is that mass and weight are different concepts.  When we buy 
a quantity of goods, like flour for instance, we put the flour on a 
weighing machine, which measures the weight but, under the metric 
system, we quote the weight in units of mass (Kg). 

Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring 
machine to Panama and measure out another 10 Kg, we will find that the 
two 10 Kg bags of flour are different (by a tiny amount).  This takes us 
back to the original (correct) premise that mass does not vary and so 
there is something wrong with our experiment. 

The something wrong is that we used a weighing machine (instead of a 
"massing" machine) and implicitly applied a constant to convert the 
weight into mass.  The constant is the thing that varies with where you 
are on the Earth and mainly consists of the acceleration due to the 
Earth's gravity, minus the centrifugal force caused by the Earth's 
spin.  Both contributions vary around the globe.

Again, apologies for the non-quaky topic.

Ian

Barry Lotz wrote:

    
Hi All
 If I remember my physics, mass does not vary with location (unless 
you are traveling very fast) but force does ( f=m*a) . the earths 
acceleration does vary with location.
regards
Barry


ian <ian@...........> wrote:

    at the risk of religious wars(!), the "kilo" is subject to
    variation from place to place because we use a weighing machine to
    measure it!

    Sigh.

    :-)

    Ian


    ChrisAtUpw@....... wrote:

      
    In a message dated 04/04/2006, ian@........... writes:

        the comparrison is deeply flawed.  A metric tonne is a unit
        of mass, a ton is a unit of force. Someone screwed up
        significantly when we went metric. It should have been
        Newtons or Kilo-Newtons for measuring weight.

        Ian. 

    Hi Ian,
     
        No, it should not be defined as the force. If it were, the
    actual quantity (mass) would vary from place to place. The ton in
    commerce is also mass. Going metric wasn't a 'screw up'?
     
        Regards,
     
        Chris Chapman
        
      
    

--
Jim Hannon
http://www.fmtcs.com/web/jmhannon/
42,11.90N,91,39.26W
WB0TXL
--
__________________________________________________________

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: Man Made Quake From: "Geoffrey" gmvoeth@........... Date: Mon, 10 Apr 2006 19:03:50 -0700 English units are in SLUGS which I believe is the weight in pounds avdp. divided by the acceleration of gravity. This value in slugs should not change anywhere in the known universe as far as I can understand. Maybe near the speed of light since mass increases with relative velocity ??? or possibly near a black hole ??? Regards; gmvoeth ----- Original Message ----- From: "ian" To: Sent: Monday, April 10, 2006 8:25 AM Subject: Re: Man Made Quake __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Infrasound revisited From: Barry Lotz barry_lotz@............. Date: Mon, 10 Apr 2006 20:14:59 -0700 (PDT) Hi Chris This reminds me of a sensor I built years ago with piezoelectric disks. It looked like a giant childs "jack".It was constructed of acrylic sheets and tubing.The center was a glue together cube. It had 6 ~1" diameter tubes about 6" long which radiated out from the center in the 6 perpendicular directions.The end of each of the 6 tubes had a glued on 1" piezo disk.I filled the whole thing with glyserine. I was going to connect the opposing disks in a half wheatstone bridge. The thought was I would have a triaxial accelerometer by measuring the pressure diferences from one side of the liquid mass to the other. When I found out what the response was from a radio shack mag vs frequency plot for the disk I thought I would measure no low frequencies and put the contraption aside. Maybe I was incorrect and had chosen the wrong disk. I can still blow the dust off of it.:) Regards Barry ChrisAtUpw@....... wrote: You can get greatly extended LF range and reduced noise using a 2" electret piezo speaker as the sensor. They have a capacity of ~65 nF, so with a 47 M Ohm input impedance, you can get a Tc of 3 sec, corresponding to a period of 19 sec, 0.05Hz. The straight sided 1L "food" flasks can be modified as low temperature drift capacities. I use 100 M Ohm to get to 40 sec period with an OPA604 opamp. It is an advantage to fill the capacity with the lowest density polyurethane foam. This ensures a near isothermal pressure response as opposed to an adiabatic / slump response and gives about 40% more output. The pressure / temperature relaxation time constant of this system seems to be about 0.1 sec. The thermal drift can be reduced if necessary by adding candle wax to the inside of the flask to increase the 'thermal mass'. The thermal time constant of an empty flask for ambient temperature changes may be about 1/2 hr. You can also use a screw top glass jar with a restriction tube as a simple series low pass RC input filter to limit the pulse / noise response. You need to use a ~constant disk temperature to avoid LARGE voltage drifts. As with all sensitive LF microphones, you do need to limit the wind noise, preferably with a loop of porous irrigation hose, maybe 10 to 30 m diameter, with solid cross connecting tubes to the sensor in the centre. Panasonic Electret Condenser Microphone WM-034DM The Sellers web address: Hi-Tech Enterprises, Inc. http://www.videoequipment.com (Note they are a discontinued line) You can download the data on these WM-034 microphones from: http://www.panasonic.com/industrial/components/audio/aud_mic.htm If you buy the CURRENT Panasoic WM61A, you will get a higher sensitivity. I suspect that the VLF response is likely to be similar. You can also use these for intruder detection. You can't open a window or a door without getting quite a large signal. There is a comprehensive web page giving details of several types of infrasonic sensor at http://earth.unh.edu/johnson/MICROPHONES/microphone_list.html This is worth serious attention for anyone interested in infrasound. Regards, Chris Chapman
Hi Chris
 This reminds me of a sensor I built years ago with piezoelectric disks. It looked like a giant childs "jack".It was constructed of acrylic sheets and tubing.The center was a glue together cube. It had 6 ~1" diameter tubes about 6" long which radiated out from the center in the 6 perpendicular directions.The end of each of the 6 tubes had a glued on 1" piezo disk.I filled the whole thing with glyserine. I was going to connect the opposing disks in a half wheatstone bridge. The thought was I would have a triaxial accelerometer by measuring the pressure diferences from one side of the liquid mass to the other. When I found out what the response was from a radio shack mag vs frequency plot for  the disk  I thought I would measure no low frequencies and put the contraption aside. Maybe I was incorrect and had chosen the wrong disk. I can still blow the dust off of it.:)    
Regards
Barry

ChrisAtUpw@....... wrote:
    You can get greatly extended LF range and reduced noise using a 2" electret piezo speaker as the sensor. They have a capacity of ~65 nF, so with a 47 M Ohm input impedance, you can get a Tc of 3 sec, corresponding to a period of 19 sec, 0.05Hz.
    The straight sided 1L "food" flasks can be modified as low temperature drift capacities. I use 100 M Ohm to get to 40 sec period with an OPA604 opamp.
    It is an advantage to fill the capacity with the lowest density polyurethane foam. This ensures a near isothermal pressure response as opposed to an adiabatic / slump response and gives about 40% more output. The pressure / temperature relaxation time constant of this system seems to be about 0.1 sec.
    The thermal drift can be reduced if necessary by adding candle wax to the inside of the flask to increase the 'thermal mass'. The thermal time constant of an empty flask for ambient temperature changes may be about 1/2 hr.
    You can also use a screw top glass jar with a restriction tube as a simple series low pass RC input filter to limit the pulse / noise response.
    You need to use a ~constant disk temperature to avoid LARGE voltage drifts. 
    As with all sensitive LF microphones, you do need to limit the wind noise, preferably with a loop of porous irrigation hose, maybe 10 to 30 m diameter, with solid cross connecting tubes to the sensor in the centre.
 
Panasonic Electret Condenser Microphone WM-034DM
   The Sellers web address:
   Hi-Tech Enterprises, Inc. http://www.videoequipment.com

(Note they are a discontinued line)
You can download the data on these WM-034 microphones from:
http://www.panasonic.com/industrial/components/audio/aud_mic.htm
 
    If you buy the CURRENT Panasoic WM61A, you will get a higher sensitivity. I suspect that the VLF response is likely to be similar. You can also use these for intruder detection. You can't open a window or a door without getting quite a large signal.
 
    There is a comprehensive web page giving details of several types of infrasonic sensor at http://earth.unh.edu/johnson/MICROPHONES/microphone_list.html
    This is worth serious attention for anyone interested in infrasound.
 
    Regards,
 
    Chris Chapman

Subject: SF 'quake simulations From: Bob Barns royb1@........... Date: Tue, 11 Apr 2006 10:46:45 -0400 Hi gang, http://earthquake.usgs.gov/regional/nca/1906/simulations/ offers some simulations of the San Francisco 'quake. Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Man Made Quake From: "Jack Ivey" ivey@.......... Date: Tue, 11 Apr 2006 16:51:28 -0400 Just to pound this into the ground a little more... 1 pound force =3D force unit commonly known as a pound 1 pound mass =3D mass that produces 1 pound force in 1 g (32.17 = ft/sec^2)=20 gravitational field 1 slug =3D mass that accelerates at 1 foot/sec^2 when acted on by=20 1 pound force 1 poundal =3D force required to produce a 1 foot/sec^2 acceleration of a 1 pound mass With units like this, who needs SI? J. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: "Geoffrey" gmvoeth@........... Date: Tue, 11 Apr 2006 14:43:08 -0700 English unit for mass is only the SLUG Pound is only used as force. At least this is what I was taught at ASU by Professor Voss. It seems to me there is no such animal as a mass named pound. Metric units have Newton's for force and grams for mass. It seems to me that units are terribly misused but I an not absolutely certain about that. The world of science places different meanings on these words then do the laymen. I wish we would all just go metric everything/everywhere. I think most folks are three ounces short of a pound when they use the hyper-complex English measures. All this complexity seems designed to be used by merchants to separate man from his gold. It would be interesting to see a mathematician or a physicist in the white house instead of the ubiquitous politicians. Regards: gmvoeth ----- Original Message ----- From: "Jack Ivey" To: Sent: Tuesday, April 11, 2006 1:51 PM Subject: RE: Man Made Quake Just to pound this into the ground a little more... 1 pound force = force unit commonly known as a pound 1 pound mass = mass that produces 1 pound force in 1 g (32.17 ft/sec^2) gravitational field 1 slug = mass that accelerates at 1 foot/sec^2 when acted on by 1 pound force 1 poundal = force required to produce a 1 foot/sec^2 acceleration of a 1 pound mass With units like this, who needs SI? J. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: ChrisAtUpw@....... Date: Tue, 11 Apr 2006 19:33:19 EDT In a message dated 11/04/2006, gmvoeth@........... writes: English unit for mass is only the SLUG Pound is only used as force. Hi Geoff, The ounce, pound, ton, slug, gm, kg and tonne are all mass units. See. _http://www.kayelaby.npl.co.uk/units_and_fundamental_constants/1_1/1_1_3.html_ (http://www.kayelaby.npl.co.uk/units_and_fundamental_constants/1_1/1_1_3.html) Regards, Chris Chapman
In a message dated 11/04/2006, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>English=20 unit for mass is only the SLUG
Pound is only used as=20 force.
Hi Geoff,
 
    The ounce, pound, ton, slug, gm, kg and tonne a= re=20 all mass units.
See. http://www.kayelaby.npl.co.uk/units_and_fundamental_constants/1_1/= 1_1_3.html
 
    Regards,
 
    Chris Chapman
Subject: Re: 2006 SF Quake From: Richard Webb dwebb002@............. Date: Wed, 12 Apr 2006 09:24:39 -0400 Considering that only 4 people responded expressing an interest in a PSN meeting, perhaps we could scale it down a bit and have a beer. Dick John or Jan Lahr wrote: > I'll be attending the meeting. Maybe we should have an informal PSN > meeting one evening? > Tuesday or Wednesday would be the best for me. (April 18 or 19). > > Cheers, > John > > At 02:31 PM 3/29/2006, you wrote: >> Hi, >> >> The SSA is having the 2006 meeting in SF the week of April 17. Are >> any PSN types going to be there? >> >> Dick >> Raleigh, NC >> __________________________________________________________ >> >> 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: 2006 SF Quake From: "Geoffrey" gmvoeth@........... Date: Wed, 12 Apr 2006 09:51:29 -0700 Hello; It takes both money and time for the luxury of attending such meetings...I would recommend to everyone to get something like MSN Messenger installed on their machine then holding a chat conference. You can do a lot of things with that program. But beware it seems once you install it if you want to get rid of it that will not be as easy. You might think that is just for kids but you can open several windows for a conference like call for real time chatting. You can transfer files and if you got high speed cable you might also use a webcam or audio or something like that. MSN Messenger used to be free. You could save bookoo bucks. It is my belief most amateurs will not have both money and time at the same time. Just an idea. Regards; gmvoeth Considering that only 4 people responded expressing an interest in a PSN meeting, perhaps we could scale it down a bit and have a beer. Dick ----- Original Message ----- From: "Richard Webb" To: Sent: Wednesday, April 12, 2006 6:24 AM Subject: Re: 2006 SF Quake __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: AD7142 ? From: Brett Nordgren Brett3kg@............. Date: Wed, 12 Apr 2006 14:19:39 -0400 Hi All, Has anyone looked at the Analog Devices AD7142 Capacitance to Digital Converter? I wonder if it might be useful for amateur seismometers. They sell an evaluation board that has all the electronics to give both I2C and USB data outputs. Specs seem quite good. With a typical balanced-capacitance sensor, +/- 1mm spacing, at a 50Hz sample rate, they claim specs equivalent to: 0.17 nm /degC temp drift 0.3nm / sqrt-Hz noise 2.1 nm RMS noise 14 nm p-p noise Resolution (24bit) much better than the noise. Any thoughts on why this wouldn't make a good starting point? Regards, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Power Supply Question? From: "Charles Staniger" cstaniger@............ Date: Wed, 12 Apr 2006 13:44:59 -0500 Hello Everyone, I am a junior in college and last summer I build a seismograph for a school project. The amplifier and filter work great together, but when I connect the power supply to the amp. and filter the system doesn’t work. At the end of this email I have provided the URL's for the schematics of the amplifier, filter, and the power supply. Currently, the amplifier and filter are using a quad power, power supply, but I would like to build my own power supply. My question is, Does anyone know of any power supply schematics that would work with my amplifier and filter? Amplifier and Filter: http://users.viawest.net/~aloomis/seisfilt.htm Power supply: http://users.viawest.net/~aloomis/seisprea.htm Sincerely, Charles Staniger President, Carthage College Habitat for Humanity Chapter __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re:AD7142 ? From: Brett Nordgren Brett3kg@............. Date: Wed, 12 Apr 2006 14:55:13 -0400 My bad. Meant to say AD7745 / 7746 Sorry, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Power Supply Question? From: Brett Nordgren Brett3kg@............. Date: Wed, 12 Apr 2006 15:29:54 -0400 Hi Charles, Your regulators should probably be able to do the job. The symptom, "doesn't work" covers an enormous range of possibilities, but I'll take a wild shot at it. National recommends a capacitor from each regulator's output terminal to ground, located near the IC. They suggest a 1uf tantalum, or alternatively a 25uf aluminum electrolytic. That's probably needed to prevent oscillation and it will also help keep the regulator's output impedance down at high frequencies. If that's not it, get out a DC-coupled oscilloscope and I can give you some other suggestions of what to look for. If it were my circuit, I'd first sit down and make very sure that what I'd wired up matched my schematic. That usually fixes about 80% of the circuits I work on. Regards, Brett At 01:44 PM 4/12/2006 -0500, you wrote: >Hello Everyone, > I am a junior in college and last summer I build a >seismograph for a school project. The amplifier and filter >work great together, but when I connect the power supply to >the amp. and filter the system doesn't work. At the end of >this email I have provided the URL's for the schematics of >the amplifier, filter, and the power supply. > Currently, the amplifier and filter are using a quad >power, power supply, but I would like to build my own power >supply. My question is, Does anyone know of any power >supply schematics that would work with my amplifier and >filter? > > >Amplifier and Filter: > http://users.viawest.net/~aloomis/seisfilt.htm > >Power supply: >http://users.viawest.net/~aloomis/seisprea.htm > >Sincerely, > > >Charles Staniger >President, Carthage College Habitat for Humanity Chapter __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Power Supply Question? From: "Keith Payea" kpayea@........... Date: Wed, 12 Apr 2006 12:33:18 -0700 Charles: Your schematics don't show any capacitors on the regulated supplies. LM78xx and 79xx regulators are notorious for oscillating if they have no output capacitors. For best results you should have 10uF or more on each power supply for each circuit block, plus 0.1uF caps for each IC. At higher frequencies it gets more complex, but this should work fine at seismic frequencies. Keith -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Charles Staniger Sent: Wednesday, April 12, 2006 11:45 AM To: psn-l@.............. Subject: Power Supply Question? Hello Everyone, I am a junior in college and last summer I build a seismograph for a school project. The amplifier and filter work great together, but when I connect the power supply to the amp. and filter the system doesn't work. At the end of this email I have provided the URL's for the schematics of the amplifier, filter, and the power supply. Currently, the amplifier and filter are using a quad power, power supply, but I would like to build my own power supply. My question is, Does anyone know of any power supply schematics that would work with my amplifier and filter? Amplifier and Filter: http://users.viawest.net/~aloomis/seisfilt.htm Power supply: http://users.viawest.net/~aloomis/seisprea.htm Sincerely, Charles Staniger President, Carthage College Habitat for Humanity Chapter __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Power Supply Question? From: "Dewayne" n0ssy@........... Date: Wed, 12 Apr 2006 13:51:34 -0600 Charles, send me your E-Mail address and I'll send you the schmatic for the power supply I use with the same amp you are using. concact me at n0ssy@........... I tried to send it via psn server and it gets rejected for being to large. ----- Original Message ----- From: "Charles Staniger" To: Sent: Wednesday, April 12, 2006 12:44 PM Subject: Power Supply Question? > Hello Everyone, > I am a junior in college and last summer I build a > seismograph for a school project. The amplifier and filter > work great together, but when I connect the power supply to > the amp. and filter the system doesn't work. At the end of > this email I have provided the URL's for the schematics of > the amplifier, filter, and the power supply. > Currently, the amplifier and filter are using a quad > power, power supply, but I would like to build my own power > supply. My question is, Does anyone know of any power > supply schematics that would work with my amplifier and > filter? > > > Amplifier and Filter: > http://users.viawest.net/~aloomis/seisfilt.htm > > Power supply: > http://users.viawest.net/~aloomis/seisprea.htm > > Sincerely, > > > Charles Staniger > President, Carthage College Habitat for Humanity Chapter > > > __________________________________________________________ > > 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: Earthquake news regarding San Andreas From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 12 Apr 2006 21:50:22 +0000 Hi all I want to point you to this news regarding rather intresting earthquake activiti near San Andreas. The news is here. http://www.eurekalert.org/pub_releases/2006-04/nsf-vdd041206.php Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Power Supply Question? From: ChrisAtUpw@....... Date: Wed, 12 Apr 2006 18:07:29 EDT In a message dated 12/04/2006, cstaniger@............ writes: I am a junior in college and last summer I build a seismograph for a school= =20 project. The amplifier and filter work great together, but when I connect=20 the power supply to the amp. and filter the system doesn=E2=80=99t work. =20 Hi Charles, =20 It sounds like the PSU doesn't work properly.=20 =20 Add a fuseholder and a 1/2A fuse in series with the input winding on th= e=20 'live' side. Add 47 mu F electrolytic + 0.1 mu F ceramic capacitors between the=20 common line and both the +ve and the -ve supply rails. Check for correct po= larity.=20 Use components rated 16V or preferably more.. Check the wiring for correct connections. Note that 7812 and 7912=20 Voltage Regulators have different pin out connections!! Check for good sold= ered=20 joints and no 'solder bridges'. The regulators should each have clip on hea= t=20 sinks, electrically isolated from each other. Connect a multimeter to the common output. On AC volts, the readings on both AC rectifier terminals should be 12 t= o=20 13 V. On DC volts, the two 4,700 mu F capacitors should read about +16 to +17= =20 V and -16 to -17 V. On DC volts, the output rails should read +12 and -12 V +/-4% On AC volts, the output rails should read a few milli volts. My question is, Does anyone know of any power supply schematics that would=20 work with my amplifier and filter? =20 Make the fuse and capacitor additions to the circuit diagram. _http://users.viawest.net/~aloomis/seisprea.htm_=20 (http://users.viawest.net/~aloomis/seisprea.htm)=20 =20 Hope that this helps. =20 Regards, =20 Chris Chapman
In a message dated 12/04/2006, cstaniger@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am a=20 junior in college and last summer I build a seismograph for a school=20 project.  The amplifier and filter work great together, but when I=20 connect the power supply to
the amp. and filter the system doesn=E2=80= =99t=20 work. 
Hi Charles,
 
    It sounds like the PSU doesn't work properly.=20
 
    Add a fuseholder and a 1/2A fuse in series with= the=20 input winding on the 'live' side.
    Add 47 mu F electrolytic + 0.1 mu F cerami= c=20 capacitors between the common line and both the +ve and the -ve supply rails= ..=20 Check for correct polarity. Use components rated 16V or preferably=20 more..
    Check the wiring for correct connections. Note=20= that=20 7812 and 7912 Voltage Regulators have different pin out=20 connections!! Check for good soldered joints and no 'solder bridges= '.=20 The regulators should each have clip on heat sinks, electrically isolated fr= om=20 each other.
    Connect a multimeter to the common output.
    On AC volts, the readings on both AC rectifier=20 terminals should be 12 to 13 V.
    On DC volts, the two 4,700 mu F capacitors shou= ld=20 read about +16 to +17 V and -16 to -17 V.
    On DC volts, the output rails should read +12 a= nd=20 -12 V +/-4%
    On AC volts, the output rails should read a few= =20 milli volts.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>My=20 question is, Does anyone know of any power supply schematics that would wo= rk=20 with my amplifier and filter? 
    Make the fuse and capacitor additions to the=20 circuit diagram.
    http://users.viawest= ..net/~aloomis/seisprea.htm
 
    Hope that this helps.
 
    Regards,
 
    Chris Chapman
Subject: Re: Conference / meetings From: ChrisAtUpw@....... Date: Wed, 12 Apr 2006 18:52:51 EDT In a message dated 12/04/2006, gmvoeth@........... writes: It takes both money and time for the luxury of attending such meetings.. I would recommend to everyone to get something like MSN Messenger installed on their machine then holding a chat conference. You can do a lot of things with that program. But beware it seems once you install it, if you want to get rid of it that will not be as easy. Hi All, The membership of psn is world wide. The current means of communication is via EMail, but without any attachments for diagrams or photographs. This is quite a limitation. I am not sure how many members would want to / can actively participate in a formal on-line conference? Most would probably be interested in 'listening in' to a meeting with several 'theme' papers + discussion groups, centred around seismology. Maybe using WebCams? Maybe focussed lectures / demonstrations on a DVD and discussion groups later on? Can we cope with the various ww recording formats? These lectures could become a valuable 'resource'? We might be able to get Iris / Spi-Net interested? Regards, Chris Chapman
In a message dated 12/04/2006, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>    It takes both money and time for the luxu= ry of=20 attending such meetings.. I would recommend to everyone to get something l= ike=20 MSN Messenger installed on their machine then holding a chat conference. Y= ou=20 can do a lot of things with that program. But beware it seems once you ins= tall=20 it, if you want to get rid of it that will not be as=20 easy.
Hi All,
 
    The membership of psn is world wide. The curren= t=20 means of communication is via EMail, but without any attachments for diagram= s or=20 photographs. This is quite a limitation.
 
    I am not sure how many members would want to /=20= can=20 actively participate in a formal on-line conference? Most would probably be=20 interested in 'listening in' to a meeting with several 'theme' papers +=20 discussion groups, centred around seismology. Maybe using=20 WebCams?     
    Maybe focussed lectures / demonstrations on a D= VD=20 and discussion groups later on? Can we cope with the various ww recordi= ng=20 formats? These lectures could become a valuable 'resource'?
 
    We might be able to get Iris / Spi-Net interest= ed?=20
 
    Regards,
 
    Chris Chapman
 
    
Subject: RE: 2006 SF Quake From: "Steve Hammond" shammon1@............. Date: Wed, 12 Apr 2006 17:49:09 -0700 Jan Froom contacted me and we can both make it on Tuesday 4/18 at 6:30 for dinner. That will make six by our count. Let me suggest a place. In Union Squear one block west of Union Square / Macys on Geary. Max’s Diner - 398 Geary/Mason - Tel: 415-646-8600 - Huge menu for lunch, dinner and post-theatre. Great Desserts!! Easy parking in Union Square garage. Beer's would be fun but we got to drive home... http://www.mapquest.com/maps/map.adp?formtype=address&addtohistory=&address= 398%20Geary%20St&city=San%20Francisco&state=CA&zipcode=94102%2d1802&country= US&geodiff=1 Will this work for everybody? Regards, Steve Hammond -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of Richard Webb Sent: Wednesday, April 12, 2006 6:25 AM To: psn-l@.............. Subject: Re: 2006 SF Quake Considering that only 4 people responded expressing an interest in a PSN meeting, perhaps we could scale it down a bit and have a beer. Dick John or Jan Lahr wrote: > I'll be attending the meeting. Maybe we should have an informal PSN > meeting one evening? > Tuesday or Wednesday would be the best for me. (April 18 or 19). > > Cheers, > John > > At 02:31 PM 3/29/2006, you wrote: >> Hi, >> >> The SSA is having the 2006 meeting in SF the week of April 17. Are >> any PSN types going to be there? >> >> Dick >> Raleigh, NC >> __________________________________________________________ >> >> 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) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: AD7142 ? From: Jim Hannon jmhannon@......... Date: Wed, 12 Apr 2006 22:59:46 -0500 I got some samples the other day. I think they will be usefull. Going to wire them up to a USB adaptor. Jim Hannon Brett Nordgren wrote: > Hi All, > > Has anyone looked at the Analog Devices AD7142 Capacitance to Digital > Converter? I wonder if it might be useful for amateur seismometers. > > They sell an evaluation board that has all the electronics to give > both I2C and USB data outputs. > > Specs seem quite good. > With a typical balanced-capacitance sensor, +/- 1mm spacing, at a 50Hz > sample rate, they claim specs equivalent to: > > 0.17 nm /degC temp drift > 0.3nm / sqrt-Hz noise > 2.1 nm RMS noise > 14 nm p-p noise > Resolution (24bit) much better than the noise. > > Any thoughts on why this wouldn't make a good starting point? > > Regards, > Brett > > > __________________________________________________________ > > 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:AD7142 ? From: Barry Lotz barry_lotz@............. Date: Wed, 12 Apr 2006 21:25:34 -0700 (PDT) Hi Brett STM wrote as a solution to LVDTs "The common solution is to use a capacitive bridge transducer, where a moving vane moves between two fixed plates that form a capacitive bridge that is unbalanced by the movement of the vane. With proper geometry, these can be very sensitive and linear over a range of several hundred microns. However, they are difficult to construct and have a working gap of less than a millimeter, and are prone to off axis sensitivity. They usually operate at relatively high frequencies, from khz to mhz, which complicates design and implementation problems" It looks like the AD device would solve some of these concerns. He then goes on to describe the VRDT. I suppose for the VBB sensor this would greatly simplify the electronic design if one can deal with small sensor gaps. I'm not sure about the noise. Does the VBB measure displacements in the 1 ą nm range? --- Just thinking out loud. I think it greatly depends on what type of sensing one wants to do local,regional or teleseismic. I like the possibility's. Regards Barry Brett Nordgren wrote: My bad. Meant to say AD7745 / 7746 Sorry, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Hi Brett
  STM wrote as a solution to LVDTs "The common solution is to use a capacitive bridge transducer, where a moving vane moves between two fixed plates that form a capacitive bridge that is unbalanced by the movement of the vane. With proper geometry, these can be very sensitive and linear over a range of several hundred microns. However, they are difficult to construct and have a working gap of less than a millimeter, and are prone to off axis sensitivity. They usually operate at relatively high frequencies, from khz to mhz, which complicates design and implementation problems" It looks like the AD device would solve some of these concerns. He then goes on to describe the VRDT. I suppose for the VBB sensor this would greatly simplify the electronic design if one can deal with small sensor gaps. I'm not sure about the noise. Does the VBB measure displacements in the 1 ą nm range?   --- Just thinking out loud. I think it greatly depends on what type of sensing one wants to do local,regional or teleseismic. I like the possibility's.
Regards
Barry


Brett Nordgren <Brett3kg@bnordgren.org> wrote:
My bad.

Meant to say AD7745 / 7746

Sorry,
Brett


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Subject: Re: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the Square From: Larry Cochrane lcochrane@.............. Date: Wed, 12 Apr 2006 23:07:40 -0700 Sounds good. See you all there! Regards, Larry Cochrane Redwood City, PSN >I like the Union Square plan, so let's go with that location. >Could you please send this to the rest of the PSN list? >From the web: >Max's on the Square >398 Geary St >San Francisco, CA 94102-1802 View Map >(650) 873-6297 >Cross Street: Mason Street >Editorial Profile >Enormous sandwiches, decadent desserts and a New York sensibility >keep this ... >Cheers, >John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the Square From: "Steve Hammond" shammon1@............. Date: Wed, 12 Apr 2006 23:28:52 -0700 Sound good-- Jan and I will see you guys Tuesday 4/18 at 6:30 next week. Steve -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of Larry Cochrane Sent: Wednesday, April 12, 2006 11:08 PM To: John Lahr Cc: Richard Webb; Keith Payea; psn-l@.............. Subject: Re: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the Square Sounds good. See you all there! Regards, Larry Cochrane Redwood City, PSN >I like the Union Square plan, so let's go with that location. >Could you please send this to the rest of the PSN list? >From the web: >Max's on the Square >398 Geary St >San Francisco, CA 94102-1802 View Map >(650) 873-6297 >Cross Street: Mason Street >Editorial Profile >Enormous sandwiches, decadent desserts and a New York sensibility >keep this ... >Cheers, >John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the From: apsn apsn@........... Date: Wed, 12 Apr 2006 22:46:43 -0800 You all have one for me. Wish I could join you. have fun! Bob Hammond Fairbanks At 10:28 PM 4/12/2006, you wrote: >Sound good-- Jan and I will see you guys Tuesday 4/18 at 6:30 next week. >Steve > >-----Original Message----- >From: psn-l-request@.............. >[mailto:psn-l-request@................. Behalf Of Larry Cochrane >Sent: Wednesday, April 12, 2006 11:08 PM >To: John Lahr >Cc: Richard Webb; Keith Payea; psn-l@.............. >Subject: Re: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the >Square > > >Sounds good. See you all there! > >Regards, >Larry Cochrane >Redwood City, PSN > > >I like the Union Square plan, so let's go with that location. > >Could you please send this to the rest of the PSN list? > > >From the web: > >Max's on the Square > > >398 Geary St > >San Francisco, CA 94102-1802 View Map > >(650) 873-6297 > >Cross Street: Mason Street > > >Editorial Profile > > >Enormous sandwiches, decadent desserts and a New York sensibility > >keep this ... > > >Cheers, > >John > > >__________________________________________________________ > >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: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the Square From: Richard Webb dwebb002@............. Date: Thu, 13 Apr 2006 08:46:33 -0400 Nancy and I will see you at Tommy's Joint. Dick Larry Cochrane wrote: > Sounds good. See you all there! > > Regards, > Larry Cochrane > Redwood City, PSN > > >I like the Union Square plan, so let's go with that location. > >Could you please send this to the rest of the PSN list? > > >From the web: > >Max's on the Square > > >398 Geary St > >San Francisco, CA 94102-1802 View Map > >(650) 873-6297 > >Cross Street: Mason Street > > >Editorial Profile > > >Enormous sandwiches, decadent desserts and a New York sensibility > >keep this ... > > >Cheers, > >John > > > __________________________________________________________ > > 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: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the Square From: Richard Webb dwebb002@............. Date: Thu, 13 Apr 2006 08:53:38 -0400 Oops, we'll see you at Max's. Dick Larry Cochrane wrote: > Sounds good. See you all there! > > Regards, > Larry Cochrane > Redwood City, PSN > > >I like the Union Square plan, so let's go with that location. > >Could you please send this to the rest of the PSN list? > > >From the web: > >Max's on the Square > > >398 Geary St > >San Francisco, CA 94102-1802 View Map > >(650) 873-6297 > >Cross Street: Mason Street > > >Editorial Profile > > >Enormous sandwiches, decadent desserts and a New York sensibility > >keep this ... > > >Cheers, > >John > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the Square From: "Connie and Jim Lehman" lehmancj@........... Date: Thu, 13 Apr 2006 08:26:33 -0400 PSN GROUP--Greetings from Virginia---Count Connie & me in the Max on the Square gathering, 6:30, Tues. eve.-- Jim ----- Original Message ----- From: "Richard Webb" To: "Larry Cochrane" Cc: "John Lahr" ; "Keith Payea" ; Sent: Thursday, April 13, 2006 8:53 AM Subject: Re: 2006 SF Quake, PSN Meeting, Tuesday, 6:30 pm, Max's on the Square > Oops, we'll see you at Max's. > > Dick > > Larry Cochrane wrote: > > Sounds good. See you all there! > > > > Regards, > > Larry Cochrane > > Redwood City, PSN > > > > >I like the Union Square plan, so let's go with that location. > > >Could you please send this to the rest of the PSN list? > > > > >From the web: > > >Max's on the Square > > > > >398 Geary St > > >San Francisco, CA 94102-1802 View Map > > >(650) 873-6297 > > >Cross Street: Mason Street > > > > >Editorial Profile > > > > >Enormous sandwiches, decadent desserts and a New York sensibility > > >keep this ... > > > > >Cheers, > > >John > > > > > > > > __________________________________________________________ > > 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: AD7745 (was AD7142 ?) From: Brett Nordgren Brett3kg@............. Date: Thu, 13 Apr 2006 09:48:15 -0400 Barry, To see what the 7745 could do, I assumed a balanced sensor with plates=20 spaced 1mm on either side of the moving plate and found I needed an area of= =20 3.4 cm^2 to best use the range of the 7745 (+/- 4pF). Then I assumed a=20 sampling rate of 50Hz. The biggest issue is that the output is digital and= =20 that presents some serious problems when you try to design it into a=20 feedback instrument. At 09:25 PM 4/12/2006 -0700, you wrote: >Hi Brett > STM wrote as a solution to LVDTs "The common solution is to use a=20 > capacitive bridge transducer, where a moving vane moves between two fixed= =20 > plates that form a capacitive bridge that is unbalanced by the movement=20 > of the vane. With proper geometry, these can be very sensitive and linear= =20 > over a range of several hundred microns. >However, they are difficult to construct and have a working gap of less=20 >than a millimeter, and are prone to off axis sensitivity. They usually=20 >operate at relatively high frequencies, from khz to mhz, which complicates= =20 >design and implementation problems" >It looks like the AD device would solve some of these concerns. I agree. >He then goes on to describe the VRDT. I suppose for the VBB sensor this=20 >would greatly simplify the electronic design if one can deal with small=20 >sensor gaps. Biggest VRDT problem seems to be its low drive frequency. In a feedback=20 design the large demod filters are prime contributors to loop oscillation=20 problems. >I'm not sure about the noise. Does the VBB measure displacements in the 1= =20 >=B1 nm range? With the sensor plates above, 1LSB=3D0.08nm. But I think noise is what=20 determines the useful resolution. However 0.3nm / sqrt-Hz and 2.1nm RMS at= =20 50 SPS isn't too shabby. It would be interesting to assume a seismic-mass= =20 system and model how this would compare with commercial instruments and=20 earth-noise models. I'm betting it won't look so bad. >--- Just thinking out loud. I think it greatly depends on what type of=20 >sensing one wants to do local,regional or teleseismic. I like the=20 >possibility's. It would be gread to be able to use this with feedback. No question that=20 you could use it for integral feedback, which mainly works below the low=20 frequency rolloff (say, below 0.011 Hz). You could make an awesome=20 integrator by digital summing, then feed back with a D/A. Mid frequency=20 range (derivative feedback) may not be practical. Although you could keep= =20 your beam well centered with integral feedback, without derivative feedback= =20 at higher frequencies, you're limited by the +/- 1.0mm (+/- 0.5 mm max, for= =20 linearity) sensor gap. I'm suspecting that clipping levels in the=20 mid-frequency range are going to be the biggest limitation. Many thanks for your inputs, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: AD7142 ? From: Brett Nordgren Brett3kg@............. Date: Thu, 13 Apr 2006 10:27:39 -0400 Jim, Please keep us up to speed on what results you're getting. Many thanks, Brett At 10:59 PM 4/12/2006 -0500, you wrote: >I got some samples the other day. I think they will be usefull. Going to >wire them up to a USB adaptor. > >Jim Hannon __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: AD7142 ? From: "James Hannon" jmhannon@......... Date: Thu, 13 Apr 2006 10:56:59 -0500 I hope this list does not mind the traffic. This sort of stuff is why I am on the list. My interest started with Dr Peters posts to the list about his capacitive seismograph. The parts I have are actually AD7747 which is capacitive and allows one side of the capacitor to be grounded. I will be hooking the part up to a DLP2232M http://www.dlpdesign.com/usb/2232m.shtml This will require some windows software to talk to the AD7747 and log the data but all the device driver stuff is already done. I have looked into using a DSP for a force feedback system. Have the DSP do all the feedback calculations etc. I have talked it over with some DSP experts and we agree it is possible. I am however not sure it is worth the effort. My current application would not have any feedback and a PC is quite capable of doing what I need to do with the low frequency signals. My next step is to get some PC board that I can solder the fine pitch part to so I can hook it up. Jim Hannon ---------- Original Message ---------------------------------- From: Brett Nordgren Date: Thu, 13 Apr 2006 11:14:50 -0400 >Jim, > >I'll also reply off list, just to keep the noise level down. > >Are you doing your own digital interface to the USB chip? That's more than >I'd want to try, but would be interested in what results you get. >It's clear that I need to learn enough about DSP to build something >useful. Was wondering if perhaps inserting a DSP chip between the AD7745 >and USB adaptor might not have some advantages. > >I keep having the feeling that there's something in this whole approach >that's waiting to bite us, but so far haven't been able to figure out what >it might be. > >Good luck, >Brett -- Jim Hannon http://www.fmtcs.com/web/jmhannon/ 42,11.90N,91,39.26W WB0TXL -- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Power Supply Question? From: "Charles Staniger" cstaniger@............ Date: Thu, 13 Apr 2006 12:43:02 -0500 Hello Everyone, Thank you to everyone who responded to my question. Within the next couple of weeks I will work on my System and hopefully be able to report a working amplifier, filter, and power supply system. Have a great weekend everyone! Charlie President, Carthage College Habitat for Humanity Chapter __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: AD7142 ? From: "Jack Ivey" ivey@.......... Date: Thu, 13 Apr 2006 13:48:17 -0400 Jim, Have you done any analysis to see if the data rate would be=20 sufficient to close your loop at high frequencies? One thing I have wondered about is whether the delay produced by these high-resolution A/Ds is longer than is implied by the sample rate, i.e. is there a pipeline of data coming through and your output is a few samples behind the real world. This could cause stability problems. =20 Actually, it might be worth someone calling up Analog Devices,=20 a friendly applications engineer might have some useful information. I can only speak for myself, but I'm interested in hearing developments in this area. Jack -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of James Hannon Sent: Thursday, April 13, 2006 11:57 AM To: psn-l@.............. Subject: Re: AD7142 ? I hope this list does not mind the traffic. This sort of stuff is why I am on the list.=20 My interest started with Dr Peters posts to the list about his capacitive seismograph.=20 The parts I have are actually AD7747 which is capacitive and allows one side of the capacitor to be grounded. I will be hooking the part up to a DLP2232M http://www.dlpdesign.com/usb/2232m.shtml This will require some windows software to talk to the AD7747 and log the data but all the device driver stuff is already done.=20 I have looked into using a DSP for a force feedback system. Have the DSP do all the feedback calculations etc. I have talked it over with some DSP experts and we agree it is possible. I am however not sure it is worth the effort.=20 My current application would not have any feedback and a PC is quite capable of doing what I need to do with the low frequency signals.=20 My next step is to get some PC board that I can solder the fine pitch part to so I can hook it up.=20 Jim Hannon=20 ---------- Original Message ----------------------------------=20 From: Brett Nordgren =20 Date: Thu, 13 Apr 2006 11:14:50 -0400=20 >Jim,=20 >=20 >I'll also reply off list, just to keep the noise level down.=20 >=20 >Are you doing your own digital interface to the USB chip? That's more than=20 >I'd want to try, but would be interested in what results you get.=20 >It's clear that I need to learn enough about DSP to build something=20 >useful. Was wondering if perhaps inserting a DSP chip between the AD7745=20 >and USB adaptor might not have some advantages.=20 >=20 >I keep having the feeling that there's something in this whole approach >that's waiting to bite us, but so far haven't been able to figure out what=20 >it might be.=20 >=20 >Good luck,=20 >Brett=20 -- Jim Hannon http://www.fmtcs.com/web/jmhannon/ 42,11.90N,91,39.26W WB0TXL -- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: AD7142 ? From: "James Hannon" jmhannon@......... Date: Thu, 13 Apr 2006 13:23:30 -0500 Jack, I was not considering closing the loop with this particular converter so I did not do any analysis. The data sheet is silent on the issue of pipeline delay but the max sample rate is low enough that I would not even try to use it for a closed loop system. Jim Hannon ---------- Original Message ---------------------------------- From: "Jack Ivey" Reply-To: psn-l@.............. Date: Thu, 13 Apr 2006 13:48:17 -0400 >Jim, >Have you done any analysis to see if the data rate would be >sufficient to close your loop at high frequencies? One thing I have >wondered about is whether the delay produced by these high-resolution >A/Ds is longer than is implied by the sample rate, i.e. is there a >pipeline of data coming through and your output is a few samples >behind the real world. This could cause stability problems. > >Actually, it might be worth someone calling up Analog Devices, >a friendly applications engineer might have some useful information. > >I can only speak for myself, but I'm interested in hearing developments >in this area. > >Jack > -- Jim Hannon http://www.fmtcs.com/web/jmhannon/ 42,11.90N,91,39.26W WB0TXL -- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: AD7142 ? From: Brett Nordgren Brett3kg@............. Date: Thu, 13 Apr 2006 14:29:25 -0400 Jim I second Jack's concern. I'd pretty much written off the possiblilty of doing DSP feedback at anything but very low frequency. I'd calculate that an absolute maximum for the DSP delay (assuming 37Hz gain crossover) would be about 13ms. 7ms or a bit more would probably be quite tolerable. Is there any way to do that? Brett At 01:48 PM 4/13/2006 -0400, you wrote: >Jim, >Have you done any analysis to see if the data rate would be >sufficient to close your loop at high frequencies? One thing I have >wondered about is whether the delay produced by these high-resolution >A/Ds is longer than is implied by the sample rate, i.e. is there a >pipeline of data coming through and your output is a few samples >behind the real world. This could cause stability problems. > >Actually, it might be worth someone calling up Analog Devices, >a friendly applications engineer might have some useful information. > >I can only speak for myself, but I'm interested in hearing developments >in this area. > >Jack __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: AD7142 ? From: "James Hannon" jmhannon@......... Date: Thu, 13 Apr 2006 13:50:15 -0500 I basically agree with your analysis of the delays needed. The functions needed for implementing a PID feedback loop can all be done in one sample time. So if the sample rate is high enough it should work fine. If you can balance a scooter http://www.tlb.org/scooter.html with 8 bit microcontrollers I see no reason why a DSP could not close a loop on a siesmograph with a natural period around 1 second or even 0.1 second. Jim Hannon ---------- Original Message ---------------------------------- From: Brett Nordgren Reply-To: psn-l@.............. Date: Thu, 13 Apr 2006 14:29:25 -0400 >Jim > >I second Jack's concern. I'd pretty much written off the possiblilty of >doing DSP feedback at anything but very low frequency. I'd calculate that >an absolute maximum for the DSP delay (assuming 37Hz gain crossover) would >be about 13ms. 7ms or a bit more would probably be quite tolerable. Is >there any way to do that? > >Brett > -- Jim Hannon http://www.fmtcs.com/web/jmhannon/ 42,11.90N,91,39.26W WB0TXL -- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: AD7142 ? Capacitative sensors From: ChrisAtUpw@....... Date: Thu, 13 Apr 2006 20:30:27 EDT In a message dated 13/04/2006, barry_lotz@............. writes: Hi Brett STM wrote as a solution to LVDTs "The common solution is to use a =20 capacitive bridge transducer, where a moving vane moves between two fixed p= lates that=20 form a capacitive bridge that is unbalanced by the movement of the vane.=20 With proper geometry, these can be very sensitive and linear over a range o= f=20 several hundred microns. Hi Barry, =20 The capacitance in pF =3D 0.0885xAxK / d, where A is the plate area in=20= sq=20 cm, K is the dielectric constant and d is the plate separation in cm.=20 With proper design, sensors can be linear over +/-5 mm or more. It=20 depends on what you need. It may be difficult to get the noise below 1 ppm=20= x range=20 for 10 Hz bandwidth, but it can be done. However, they are difficult to construct and have a working gap of less tha= n=20 a millimetre, and are prone to off axis sensitivity.=20 This is largely incorrect for amateur applications. If you demand 1nm=20 resolution or better, you do need special materials and construction -> Sil= ver=20 coated Invar / Platinum coated Quartz electrodes.=20 =20 There are three basic types of capacitor sensor. You can have a pair of= =20 parallel plates excited by sine or square waves with a central sensor plate= =20 which moves perpendicular to the plane. This needs voltage detection to be=20 highly linear and has a range limited by the separation of the outer plates= -=20 likely to be quite limited. If you use charge sensing, the linear range is=20 reduced to maybe 1/4. You are likely to have to bore holes in the plates to= allow=20 adequate airflow as they move. You can use two pairs of parallel plates with a central sensor plate=20 moving parallel to the plane - a split stator variable capacitor. The excit= ation=20 is applied between the pairs of plates on opposite sides of the sensor=20 plate. Charge detection is usually used with an electrical connection to ce= ntral=20 plate. The sensor range depends on the width of the moving plate, which is=20 half the overall stator width. There is no air flow problem with plate move= ment. You can use basically parallel circuit board plates with a pair of=20 excitation strips on one side, a cross coupled square / rectangular sense a= rray on=20 the other and a plate with vertical 'shadow strips' moving parallel in=20 between. It is easy to make these out of double sided glass circuit board.=20= The=20 central shadow plate does not need to be earthed. Only the fixed plates nee= d to=20 be wired up, which is a considerable advantage. The maximum movement is hal= f=20 the square 'cell size'. Again this can be quite large. See Randall Peters'=20 SDC sensor at _http://physics.mercer.edu/petepag/sens.htm_=20 (http://physics.mercer.edu/petepag/sens.htm) Charge detection is usually u= sed. An array of=20 coupled cells can be used to increase the sensitivity. It is an advantage t= o make=20 the shadow plate out of etched double sided glass board. The 'electrical=20 thickness' is the actual thickness divided by the dielectric constant. Havi= ng all=20 three boards made from the same material greatly reduces any thermal drift.= =20 There is no air flow problem with plate movement. They usually operate at relatively high frequencies, from khz to mhz, which= =20 complicates design and implementation problems"=20 Operating at 10 to 50 k Hz is just fine. You can use digital to sine=20 weighted step down counters which give very good sine waves - see=20 _http://www.eas.slu.edu/People/STMorrissey/index.html_=20 (http://www.eas.slu.edu/People/STMorrissey/index.html) Alternatively, you= can use a LTC1043 quad chopper switch=20 / oscillator with either sine or square waves. Using sine waves allows you=20= to=20 get a higher S/N ratio. XR8038 & especially XR2206 function generators can=20 give quite a good performance, as can a FET stabilised Wein Bridge oscillat= or=20 - see _http://www.keckec.com/seismo/_ (http://www.keckec.com/seismo/) . Two=20= =20 stages of RC bandpass filter are used in=20 _http://psn.quake.net/info/bb13OperManual.pdf_ (http://psn.quake.net/info/bb= 13OperManual.pdf) starting with the=20 square wave from a quartz oscillator. For low drift, avoid resonant circuit= s=20 and diode rectification. It looks like the AD device would solve some of these concerns.=20 The concerns seem to be largely illusory in practice. =20 =20 In a message dated 13/04/2006 14:48:47 GMT Daylight Time, =20 Brett3kg@............. writes:=20 Biggest VRDT problem seems to be its low drive frequency. In a feedback =20 design the large demod filters are prime contributors to loop oscillation =20 problems. So reduce the filtration and apply a DC + pulsed feedback? Use another=20 method? The feedback phase delay is only a problem if you do it this way! >I'm not sure about the noise. Does the VBB measure displacements in the 1=20= =20 >=B1 nm range? With the sensor plates above, 1LSB=3D0.08nm. But I think noise is what=20 determines the useful resolution. However 0.3nm / sqrt-Hz and 2.1nm RMS at= =20 50 SPS isn't too shabby. It would be interesting to assume a seismic-mass=20 system and model how this would compare with commercial instruments and=20 earth-noise models. I'm betting it won't look so bad. Have you measured your environmental noise level? Is 2.1 nm a realistic= =20 target? The amplitude of the 6 second ocean microseisms may be from 500 to=20 15,000 nm! =20 He then goes on to describe the VRDT. I suppose for the VBB sensor this=20 would greatly simplify the electronic design if one can deal with small sen= sor =20 gaps. I'm not sure about the noise. Does the VBB measure displacements in t= he=20 1 =B1 nm range? --- Just thinking out loud. I think it greatly depends on= =20 what type of sensing one wants to do local, regional or teleseismic. Amateur seismometers are usually limited by either microseisms or by=20 environmental noise - we can't usually choose a quiet remote site. I manage= d=20 to reduce the noise of my LVDT to about 7 nm for a 6 mm range at 10 Hz, but= my=20 environmental noise is much greater than this.=20 =20 It would be great to be able to use this with feedback. No question that=20 you could use it for integral feedback, which mainly works below the low =20 frequency roll off (say, below 0.011 Hz). You could make an awesome =20 integrator by digital summing, then feed back with a D/A. Mid frequency=20 range (derivative feedback) may not be practical. Although you could keep=20 your beam well centred with integral feedback, without derivative feedback=20 at higher frequencies, you're limited by the +/- 1.0mm (+/- 0.5 mm max, for= =20 linearity) sensor gap. I'm suspecting that clipping levels in the=20 mid-frequency range are going to be the biggest limitation. So, we may need some 'lateral thinking' here! There are 'problems that you=20 do not need to have' - like:- =20 The velocity feedback damping does not need to be generated that way! =20 Neither do we need to use that troublesome design of capacitative senso= r! =20 *** You can use JUST position + integral current / coil feedback if you=20 ALSO have a quad magnet + Cu plate for the velocity damping! Trying to prov= ide=20 velocity damping by differentiation and coil feedback is likely to very=20 significantly increase the overall circuit noise! *** =20 Regards, =20 Chris Chapman
In a message dated 13/04/2006, barry_lotz@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Brett
  STM wrote as a solution to LVDTs "The common solution is to us= e a=20 capacitive bridge transducer, where a moving vane moves between two fixed=20 plates that form a capacitive bridge that is unbalanced by the movement of= the=20 vane. With proper geometry, these can be very sensitive and linear over a=20 range of several hundred microns.
Hi Barry,
 
    The capacitance in pF =3D 0.0885xAxK / d, where= A is=20 the plate area in sq cm, K is the dielectric constant and d is the plate=20 separation in cm.
    With proper design, sensors can be linear over=20= +/-5=20 mm or more. It depends on what you need. It may be difficult to get the nois= e=20 below 1 ppm x range for 10 Hz bandwidth, but it can be done.
However, they are difficult to construct and have a working gap o= f less=20 than a millimetre, and are prone to off axis sensitivity.=20
    This is largely incorrect for amateur applicati= ons.=20 If you demand 1nm resolution or better, you do need special materials and=20 construction -> Silver coated Invar / Platinum coated Quartz electrodes.=20
 
    There are three basic types of capacitor sensor= ..=20 You can have a pair of parallel plates excited by sine or square waves with=20= a=20 central sensor plate which moves perpendicular to the plane. This nee= ds=20 voltage detection to be highly linear and has a range limited by=20 the separation of the outer plates - likely to be quite limited. If you= use=20 charge sensing, the linear range is reduced to maybe 1/4. You are likel= y to=20 have to bore holes in the plates to allow adequate airflow as they move.
    You can use two pairs of parallel plates with a= =20 central sensor plate moving parallel to the plane - a split stator=20 variable capacitor. The excitation is applied between the pairs of plates on= =20 opposite sides of the sensor plate. Charge detection is usually used with an= =20 electrical connection to central plate. The sensor range depends on=20 the width of the moving plate, which is half the overall stator wi= dth.=20 There is no air flow problem with plate movement.
    You can use basically parallel circuit board pl= ates=20 with a pair of excitation strips on one side, a cross coupled square /=20 rectangular sense array on the other and a plate with vertical 'shadow strip= s'=20 moving parallel in between. It is easy to make these out of double si= ded=20 glass circuit board. The central shadow plate does not need to be earth= ed.=20 Only the fixed plates need to be wired up, which is a considerable=20 advantage. The maximum movement is half the square 'cell size'. Aga= in=20 this can be quite large. See Randall Peters' SDC sensor at http://physics.mercer.ed= u/petepag/sens.htm Charge=20 detection is usually used. An array of coupled cells can be used to increase= the=20 sensitivity. It is an advantage to make the shadow plate out of etched doubl= e=20 sided glass board. The 'electrical thickness' is the actual thickness divide= d by=20 the dielectric constant. Having all three boards made from the same material= =20 greatly reduces any thermal drift. There is no air flow problem with plate=20 movement.
They usually operate at relatively high frequencies, from khz to=20= mhz,=20 which complicates design and implementation problems"
    Operating at 10 to 50 k Hz is just fine. You ca= n=20 use digital to sine weighted step down counters which give very good sine wa= ves=20 - see http://www.eas= ..slu.edu/People/STMorrissey/index.html =20 Alternatively, you can use a LTC1043 quad chopper switch / oscillator w= ith=20 either sine or square waves. Using sine waves allows you to get a highe= r=20 S/N ratio. XR8038 & especially XR2206 function generators can give quite= a=20 good performance, as can a FET stabilised Wein Bridge oscillator - see http://www.keckec.com/seismo/. Tw= o=20 stages of RC bandpass filter are used in http://psn.quake.net/i= nfo/bb13OperManual.pdf starting=20 with the square wave from a quartz oscillator. For low drift, avoid=20 resonant circuits and diode rectification.
It looks like the AD device would solve some of these=20 concerns. 
    The concerns seem to be largely illusory in=20 practice.
 
 
In a message dated 13/04/2006 14:48:47 GMT Daylight Time,=20 Brett3kg@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Biggest=20 VRDT problem seems to be its low drive frequency. In a feedback=20
design the large demod filters are prime contributors to loop oscillat= ion=20 problems.
    So reduce the filtration and apply a DC + pulse= d=20 feedback? Use another method?
    The feedback phase delay is only a problem if y= ou=20 do it this way!
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>I'm=20 not sure about the noise. Does the VBB measure displacements in the 1=20
>=B1 nm range?

With the sensor plates above, 1LSB=3D0.08nm.&= nbsp;=20 But I think noise is what
determines the useful resolution.  Howe= ver=20 0.3nm / sqrt-Hz and 2.1nm RMS at
50 SPS isn't too shabby.  It wou= ld=20 be interesting to assume a seismic-mass
system and model how this woul= d=20 compare with commercial instruments and
earth-noise models.  I'm=20 betting it won't look so bad.
    Have you measured your environmental noise leve= l?=20 Is 2.1 nm a realistic target? The amplitude of the 6 second ocean microseism= s=20 may be from 500 to 15,000 nm!
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2> He=20 then goes on to describe the VRDT. I suppose for the VBB sensor this would= =20 greatly simplify the electronic design if one can deal with small sen= sor=20 gaps. I'm not sure about the noise. Does the VBB measure displacement= s in=20 the 1 =B1 nm range?   --- Just thinking out loud. I think it gre= atly=20 depends on what type of sensing one wants to do local, regional or=20 teleseismic.
      Amateur seismometers are usual= ly=20 limited by either microseisms or by environmental noise - we can't usually=20 choose a quiet remote site. I managed to reduce the noise of my LVDT to abou= t 7=20 nm for a 6 mm range at 10 Hz, but my environmental noise is much greater=20 than this.
 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>It would=20 be great to be able to use this with feedback.  No question that
= you=20 could use it for integral feedback, which mainly works below the low=20
frequency roll off (say, below 0.011 Hz).  You could make an awes= ome=20
integrator by digital summing, then feed back with a D/A.  Mid=20 frequency
range (derivative feedback) may not be practical.  Alth= ough=20 you could keep
your beam well centred with integral feedback, without=20 derivative feedback
at higher frequencies, you're limited by the +/- 1= ..0mm=20 (+/- 0.5 mm max, for
linearity) sensor gap.  I'm suspecting that=20 clipping levels in the
mid-frequency range are going to be the biggest= =20 limitation.
 
    So, we may need some 'lateral thinking'=20 here! There are 'problems that you do not need to have' - like:-
 
    The velocity feedback damping does not need to=20= be=20 generated that way!
 
    Neither do we need to use that troublesome desi= gn=20 of capacitative sensor!
 
 ***   You can use JUST position +=20 integral current / coil feedback if you ALSO have a quad magne= t +=20 Cu plate for the velocity damping! Trying to provide velocity damping by=20 differentiation and coil feedback is likely to very significantly increase t= he=20 overall circuit noise!  ***
 
    Regards,
 
    Chris Chapman
Subject: Update to my earthquake webpage From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 14 Apr 2006 01:05:25 +0000 Hi all I have updated my earthquake webpage. I want to know what you think about it and to help me to locate any spelling error that i might have left in the english section of the page. The link to the webpage is in the signature. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: The New Madrid seismic zone From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 14 Apr 2006 01:37:34 +0000 Hi all I did find this news today about the New madrid seismic zone in the U.S. They think that large earthquake might happen there sometimes in the future. http://science.monstersandcritics.com/news/article_1154951.php/Big_quake_might_ravage_U.S._Midwest Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Honeywell DC001NDR5 sensor From: Barry Lotz barry_lotz@............. Date: Thu, 13 Apr 2006 20:33:44 -0700 (PDT) Hi All Not to get of the current thread but I was thinking of the honeywell pressure transducer. If one has a horizontally oriented cylinder(say 6" long - maybe 2" diameter) filled with a non-evaporative liquid of low viscosity. At each would be a manometer tube attached to the end plates and directed up and partially filled with the liquid. Attach the DC001ndrr5 to one end and maybe leave the manometer tube at the other end open (maybe closed I'm not sure). It would seem that the sensor would measure the pressure difference as the liquid moved horizontally due to seismic motion. I did the math for a column of water 6" long and got g numbers pretty low say 10^-5 for a sensor of ą 125 pa. I don't think there would be fluid flow issues at the manometer ports since the fluid velocities would seem to me low. One would probably have to put the sensor in a sealed container to minimize barometric fluxuations. I think scientific american had something like this years ago but measured the water levels some other way. Regards Barry
Hi All
 Not to get of the current thread but I was thinking of the honeywell pressure transducer. If one has a horizontally oriented cylinder(say 6" long - maybe 2" diameter) filled with a non-evaporative liquid of low viscosity. At each would be a manometer tube attached to the end plates and directed up and partially filled with the liquid. Attach the DC001ndrr5 to one end and maybe leave the manometer tube at the other end open (maybe closed I'm not sure). It would seem that the sensor would measure the pressure difference as the liquid moved horizontally due to seismic motion. I did the math for a column of water 6" long and got g numbers pretty low say 10^-5 for a sensor of ą 125 pa. I don't think there would be fluid flow issues at the manometer ports since the fluid velocities would seem to me low. One would probably have to put the sensor in a sealed container to minimize barometric fluxuations. I think scientific american had something like this years ago but measured the water levels some other way.
Regards
Barry
Subject: Re: AD7745 Capacitative sensors From: Brett Nordgren Brett3kg@............. Date: Fri, 14 Apr 2006 10:23:55 -0400 Hi Chris, I was hoping you'd get in on this thread. I enjoy hearing your ideas. At 08:30 PM 4/13/2006 -0400, you wrote: > However, they are difficult to construct and have a working gap= of > less than a millimetre, and are prone to off axis sensitivity. > > This is largely incorrect for amateur applications. If you demand 1nm= =20 > resolution or better, you do need special materials and construction ->=20 > Silver coated Invar / Platinum coated Quartz electrodes. I'm not sure pure resolution is that hard to come by. Noise & temperature= =20 sensitivity are another matter, though. > There are three basic types of capacitor sensor. >You can have a pair of parallel plates excited by sine or square waves=20 >with a central sensor plate which moves perpendicular to the plane. > You can use two pairs of parallel plates with a central sensor plate= =20 > moving parallel to the plane > You can use basically parallel circuit board plates with a pair of=20 > excitation strips on one side, a cross coupled square / rectangular=20 > sense array on the other and a plate with vertical 'shadow strips'=20 > moving parallel in between. I'd always assumed that only the first type had adequate displacement=20 sensitivity, a couple of orders of magnitude greater than the=20 others. Sounds like I need to go back and check the numbers. >They usually operate at relatively high frequencies, from khz to mhz,=20 >which complicates design and implementation problems" > > Operating at 10 to 50 k Hz is just fine. > > > The concerns seem to be largely illusory in practice. Absolutely. There's nothing that difficult with managing high audio=20 frequencies. > In a message dated 13/04/2006 14:48:47 GMT Daylight Time,=20 > Brett3kg@............. writes: >Biggest VRDT problem seems to be its low drive frequency. In a feedback >design the large demod filters are prime contributors to loop oscillation= =20 >problems. > So reduce the filtration and apply a DC + pulsed feedback? Use=20 > another method? Can you amplify on this? Not exactly sure what your'e proposing, but it=20 sounds interesting. > The feedback phase delay is only a problem if you do it this way! > >I'm not sure about the noise. Does the VBB measure displacements in the 1 > >=B1 nm range? > >With the sensor plates above, 1LSB=3D0.08nm. But I think noise is what >determines the useful resolution. However 0.3nm / sqrt-Hz and 2.1nm RMS at >50 SPS isn't too shabby. It would be interesting to assume a seismic-mass >system and model how this would compare with commercial instruments and >earth-noise models. I'm betting it won't look so bad. > Have you measured your environmental noise level? Is 2.1 nm a=20 > realistic target? The amplitude of the 6 second ocean microseisms may be= =20 > from 500 to 15,000 nm! Actually 2.1nm was no target. That's just what I calculated you could get= =20 using the AD7745. I agree that it is a good bit better than a typical home= =20 site would justify, which is why it looked so interesting. > He then goes on to describe the VRDT. I suppose for the VBB sensor this= =20 > would greatly simplify the electronic design if one can deal with small=20 > sensor gaps. I'm not sure about the noise. Does the VBB measure=20 > displacements in the 1 =B1 nm range? --- Just thinking out loud. I think= =20 > it greatly depends on what type of sensing one wants to do local,=20 > regional or teleseismic. > Amateur seismometers are usually limited by either microseisms or=20 > by environmental noise - we can't usually choose a quiet remote site. I=20 > managed to reduce the noise of my LVDT to about 7 nm for a 6 mm range at= =20 > 10 Hz, but my environmental noise is much greater than this. > > It would be great to be able to use this with feedback. > > > So, we may need some 'lateral thinking' here! There are 'problems=20 > that you do not need to have' - like:- > > The velocity feedback damping does not need to be generated that way! > > Neither do we need to use that troublesome design of capacitative= sensor! > > *** You can use JUST position + integral current / coil feedback if=20 > you ALSO have a quad magnet + Cu plate for the velocity damping! Trying=20 > to provide velocity damping by differentiation and coil feedback is=20 > likely to very significantly increase the overall circuit noise! *** I'm now thinking that's where I was heading, except for retaining the=20 "perpendicular" capacitance sensor. Since the AD7746 goes directly from=20 capacitance to digital, I was hoping to use either a PC or commercial DSP=20 chip or FPGA to do most of the Position-Velocity derivative and other=20 shaping. I like that because that needs minimal analog circuitry and what= =20 you do need (integral current feedback) is working at virtually DC. And,=20 yes, for that to work you would need a well-damped and stable spring=20 mass. Don't know how easy that is to do with a vertical, but assume=20 there's an answer. First-order displacement linearization could be done=20 digitally. Also you'd need to be sure that your displacement sensor range= =20 was adequate. Thanks for your thoughts, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: The New Madrid seismic zone From: Jim Hannon jmhannon@......... Date: Fri, 14 Apr 2006 15:34:19 -0500 We live close enough that I worry about it now and then. http://www.eas.slu.edu/Earthquake_Center/eqhist.html Jim Hannon Jón Frímann wrote: >Hi all > >I did find this news today about the New madrid seismic zone in the U.S. >They think that large earthquake might happen there sometimes in the >future. >http://science.monstersandcritics.com/news/article_1154951.php/Big_quake_might_ravage_U.S._Midwest > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Possible that large earthquake is going to strike SISZ soon From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 14 Apr 2006 23:00:48 +0000 Hi all According to the experts at Icelandic Met Office (IMO). They think that there is a risk of a large earthquake going to strike the SISZ (Southern Iceland Seismic Zone) soon. They base there opinion on this data. Yesterday there was a swarm of about 20 small earthquakes 3 km WSW of Hveragerđi (town), all of this earthquakes where smaller then 1.0Ml in size. They can't rule out the option that this is pre-activie of a larger earthquake that might strike there. I assume that they draw this from what was learned in the year 2000 in the large earthquakes that did hit the SISZ then. There is good report on those earthquakes here http://hraun.vedur.is/ja/skyrslur/June17and21_2000/index.html I wanted to let you all know of this, in case something happens. I can forward more info on this if i learn something new. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: AD7745 Capacitative sensors From: ChrisAtUpw@....... Date: Sat, 15 Apr 2006 00:24:42 EDT In a message dated 14/04/2006, Brett3kg@............. writes: > However, they are difficult to construct and have a working gap= =20 of > less than a millimetre, and are prone to off axis sensitivity. > > This is largely incorrect for amateur applications. If you demand 1nm=20 > resolution or better, you do need special materials and construction. I'm not sure pure resolution is that hard to come by. Noise & temperature=20 sensitivity are another matter, though. Hi Brett, =20 There are ways of reducing the effects of thermal expansion without=20 using exotic materials. Noise can be greatly reduced using a dual FET front= end=20 on a chopper amplifier. The latest types give about 1 nV rms / Root Hz.=20 > There are three basic types of capacitor sensor. >You can have a pair of parallel plates excited by sine or square waves=20 >with a central sensor plate which moves perpendicular to the plane. There are two major disadvantages with this type. Movement of the sensor plate displaces air between the plates on both=20 sides. This damping + spring cushion effect depends on the plate size, thei= r=20 separation and on the plate velocity - it varies a lot. The traditional met= hods=20 of reducing these problems involve boring air holes in the capacitor plates= =20 and evacuating the seismometer case.=20 This sort of sensor is only linear over the whole movement range if you= =20 use either voltage sensing or a special feedback circuit with 'floating'=20 power supplies. However, you are critically dependant on stray capacity eff= ects.=20 These can be largely compensated for sine wave excitation, but with some=20 difficulty. If you use a charge amplifier, it will only be approximately li= near=20 for 1/3 to 1/4 the available movement range. Since other designs without these problems are available, why do things= =20 the hard way? > You can use two pairs of parallel plates with a central sensor plate=20 > moving parallel to the plane > You can use basically parallel circuit board plates with a pair of=20 excitation strips on one side, a cross coupled square / rectangular sense a= rray=20 on the other and a plate with vertical 'shadow strips' moving parallel in=20 between. It is easy to make these out of double sided glass circuit board.=20= The=20 central shadow plate does not need to be earthed. Only the fixed plates nee= d=20 to be wired up, which is a considerable advantage. The maximum movement is=20 half the square 'cell size'. Again this can be quite large. See Randall Pet= ers'=20 SDC sensor at _http://physics.mercer.edu/petepag/sens.htm_=20 (http://physics.mercer.edu/petepag/sens.htm) Charge detection is usually u= sed. An array of=20 coupled cells can be used to increase the sensitivity. It is an advantage t= o=20 make the shadow plate out of etched double sided glass board. The 'electric= al=20 thickness' is the actual thickness divided by the dielectric constant. Havi= ng=20 all three boards made from the same material greatly reduces any thermal=20 drift. There is no air flow problem with plate movement. I'd always assumed that only the first type had adequate displacement=20 sensitivity, a couple of orders of magnitude greater than the=20 others. Sounds like I need to go back and check the numbers. They mostly come down to dL / L considerations. The larger you make the= =20 total range L, the more you need to amplify the signal. It is quite possibl= e=20 to maintain a very high sensitivity by detecting the whole signal range and= =20 then adding a high pass filter and more amplification. My LVDT Lehman senso= r=20 allows the first stage to give +/-10V for the allowed +/-10 mm range. This=20 signal is then put through a high pass filter and the 'AC' component is=20 amplified further. This allows resolution of a few 10s of nm on my 16 bit AD= C over=20 the whole 10 mm range. =20 > In a message dated 13/04/2006, Brett3kg@............. writes: >Biggest VRDT problem seems to be its low drive frequency. In a feedback >design the large demod filters are prime contributors to loop oscillation=20 >problems. > So reduce the filtration and apply a DC + pulsed feedback? Use=20 > another method? Can you amplify on this? Not exactly sure what your'e proposing, but it=20 sounds interesting. If you look at the circuit in=20 _http://psn.quake.net/info/bb13OperManual.pdf_ (http://psn.quake.net/info/bb= 13OperManual.pdf) two stages of RC bandpass=20 filter are used starting with the square wave from a quartz oscillator. One= =20 filter is on the input line to the differential capacitor sensor and the=20 other on the amplified output from the sensor. The output of the final ampl= ifier=20 has a DC component with a large AC ripple on it at twice the oscillator=20 frequency. This is applied to the inductive winding of the feedback coil th= rough a=20 parallel RC link to give a low phase error feedback signal. If you fully=20 smoothed the output, you would have a greater phase delay. You then add a l= ow=20 pass filter to smooth the signal for the A/D converter. > The feedback phase delay is only a problem if you do it this way! > >I'm not sure about the noise. Does the VBB measure displacements in the > >=B11 nm range? > >With the sensor plates above, 1LSB=3D0.08nm. But I think noise is what >determines the useful resolution. However 0.3nm / sqrt-Hz and 2.1nm RMS a= t >50 SPS isn't too shabby. It would be interesting to assume a seismic-mass >system and model how this would compare with commercial instruments and >earth-noise models. I'm betting it won't look so bad. > Have you measured your environmental noise level? Is 2.1 nm a=20 > realistic target? The amplitude of the 6 second ocean microseisms may be=20 > from 500 to 15,000 nm! Actually 2.1nm was no target. That's just what I calculated you could get=20 using the AD7745. I agree that it is a good bit better than a typical home= =20 site would justify, which is why it looked so interesting. The lower limit for LVDT measurements is about 0.1 nano m. With=20 capacitative sensors you can reduce this by 100. This is far smaller than t= he=20 background noise limits.=20 > He then goes on to describe the VRDT. I suppose for the VBB sensor this=20 > would greatly simplify the electronic design if one can deal with small=20 > sensor gaps. I'm not sure about the noise. Does the VBB measure=20 > displacements in the 1 =B1 nm range? --- Just thinking out loud. I thin= k=20 > it greatly depends on what type of sensing one wants to do local,=20 > regional or teleseismic. > Amateur seismometers are usually limited by either microseisms or =20 > by environmental noise - we can't usually choose a quiet remote site. I=20 > managed to reduce the noise of my LVDT to about 7 nm for a 6 mm range at=20 > 10 Hz, but my environmental noise is much greater than this. > > There are 'problems that you do not need to have' :- > > The velocity feedback damping does not need to be generated that way= ! > > Neither do we need to use that troublesome design of capacitative=20 sensor! > > *** You can use JUST position + integral current / coil feedback if=20 > you ALSO have a quad magnet + Cu plate for the velocity damping! Trying=20 > to provide velocity damping by differentiation and coil feedback is=20 > likely to very significantly increase the overall circuit noise! *** I'm now thinking that's where I was heading, except for retaining the=20 "perpendicular" capacitance sensor. =20 I suggest that you reconsider the capacitative sensor design. You reall= y=20 don't need pneumatic damping problems and it is helpful to be able to choos= e=20 your range. If you are trying to measure a few parts in a 15,000 nm signal,= =20 you need the lowest noise most linear system that you can get. A considerab= le=20 reduction in expansion coefficient is possible using either conducting=20 paint, evaporated metal, or etched metal on thin pyrex sheet glass. You can= stick=20 metal foil onto sheet glass with acrylic adhesive - don't try epoxy unless=20 you prebake the glass to over 150 C. The electrode plates can be made by ph= oto=20 etching. True chopper amplifier circuits are available. These are immune to 1/f=20 noise. The SDC type sensor offers a great constructional advantage in ease=20= of=20 wiring - no electrical connections are required to the seismic mass - and y= ou=20 can use coaxial screened cable with a charge amplifier. The design is not=20 too critical on electrode spacing, which can be quite small. Since the AD7746 goes directly from=20 capacitance to digital, I was hoping to use either a PC or commercial DSP=20 chip or FPGA to do most of the Position-Velocity derivative and other=20 shaping. I like that because that needs minimal analog circuitry and what=20 you do need (integral current feedback) is working at virtually DC. And,=20 yes, for that to work you would need a well-damped and stable spring=20 mass. First-order displacement linearization could be done digitally. Also= =20 you'd need to be sure that your displacement sensor range was adequate. There are two problems associated with either analogue or digital generatio= n=20 of a velocity feedback signal from a position signal. The generated signal=20 is inherently noisy. You can also run off the end of the voltage or count=20 scale --> system failure. The phase errors / delays need to be considered /= =20 compensated.=20 It is relatively easy to provide a very quiet precision velocity=20 feedback signal within the stop limits of the mass movement using either ma= gnet /=20 coil / resistor damping or a quad magnet / variable area damping plate. Thi= s=20 uses NO external power OR electronics! Why 'do things the hard way'? The _http://gravity.ucsd.edu/research/OFSEIS/opt_seis.html_=20 (http://gravity.ucsd.edu/research/OFSEIS/opt_seis.html) account claims a r= eduction in the=20 feedback noise using magnet / coil / resistor damping. 24 bit DACs are available for positional feedback / integral feedback. =20 Another factor which can significantly effect the overall seismometer=20 performance lies in the design of the suspension system, as you outlined in= =20 your rolling foil design.=20 The 'art' of being successful lies largely in not making mistakes and i= n=20 avoiding unnecessary problems and limitations. =20 Regards, =20 Chris Chapman
In a message dated 14/04/2006, Brett3kg@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>           However, they are=20 difficult to construct and have a working gap of
>    &nbs= p;=20      less than a millimetre, and are prone to off axis=20 sensitivity.
>
>    This is largely incorrect for=20 amateur applications. If you demand 1nm
> resolution or better, you= do=20 need special materials and construction.

I'm not sure pure resoluti= on=20 is that hard to come by.  Noise & temperature
sensitivity are= =20 another matter, though.
Hi Brett,
 
    There are ways of reducing the effects of therm= al=20 expansion without using exotic materials. Noise can be greatly reduced using= =20 a dual FET front end on a chopper amplifier. The latest types give abou= t 1=20 nV rms / Root Hz. 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>      There are three basic types of capacitor= =20 sensor.
>You can have a pair of parallel plates excited by sine or=20 square waves
>with a central sensor plate which moves perpendicular= to=20 the plane. <clip>
    There are two major disadvantages with this=20 type.
    Movement of the sensor plate displaces air betw= een=20 the plates on both sides. This damping + spring cushion effect dep= ends=20 on the plate size, their separation and on the plate velocity - it vari= es a=20 lot. The traditional methods of reducing these problems involve boring air h= oles=20 in the capacitor plates and evacuating the seismometer case. 
    This sort of sensor is only linear over the who= le=20 movement range if you use either voltage sensing or a special feed= back=20 circuit with 'floating' power supplies. However, you are critically dependan= t on=20 stray capacity effects. These can be largely compensated for sine wave=20 excitation, but with some difficulty. If you use a charge amplifier, it will= =20 only be approximately linear for 1/3 to 1/4 the available movement range.
    Since other designs without these problems are=20 available, why do things the hard way?
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     You can use two pairs of parallel plates=20= with a=20 central sensor plate
> moving parallel to the plane=20 <clip>
>     You can use basically=20 parallel circuit board plates with a pair of excitation strips on one side= , a=20 cross coupled square / rectangular sense array on the other and a plate wi= th=20 vertical 'shadow strips' moving parallel in between. It is easy to=20= make=20 these out of double sided glass circuit board. The central shadow pla= te=20 does not need to be earthed. Only the fixed plates need to be wired= up,=20 which is a considerable advantage. The maximum movement is half t= he=20 square 'cell size'. Again this can be quite large. See Randall Peters' SDC= =20 sensor at http://physics.mercer.= edu/petepag/sens.htm Charge=20 detection is usually used. An array of coupled cells can be used to increa= se=20 the sensitivity. It is an advantage to make the shadow plate out of etched= =20 double sided glass board. The 'electrical thickness' is the actual thickne= ss=20 divided by the dielectric constant. Having all three boards made from the=20= same=20 material greatly reduces any thermal drift. There is no air flow problem w= ith=20 plate movement.  <clip>

I'd always assumed that only the= =20 first type had adequate displacement
sensitivity, a couple of orders o= f=20 magnitude greater than the
others. Sounds like I need to go back=20= and=20 check the numbers.
    They mostly come down to dL / L considerations.= The=20 larger you make the total range L, the more you need to amplify the sig= nal.=20 It is quite possible to maintain a very high sensitivity by detecting the wh= ole=20 signal range and then adding a high pass filter and more amplification. My L= VDT=20 Lehman sensor allows the first stage to give +/-10V for the allowed +/-10 mm= =20 range. This signal is then put through a high pass filter and the 'AC' compo= nent=20 is amplified further. This allows resolution of a few 10s of nm on my 16 bit= ADC=20 over the whole 10 mm range.  
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>   In a message dated 13/04/2006, Brett3kg@bnordgre= n.org=20 writes:
>Biggest VRDT problem seems to be its low drive frequency. I= n a=20 feedback
>design the large demod filters are prime contributors to l= oop=20 oscillation
>problems.
>     So reduce the=20 filtration and apply a DC + pulsed feedback? Use
> another=20 method?

Can you amplify on this?  Not exactly sure what your'e= =20 proposing, but it
sounds interesting.
    If you look at the circuit in http://psn.quake.net/i= nfo/bb13OperManual.pdf two=20 stages of RC bandpass filter are used starting with the square wave fro= m a=20 quartz oscillator. One filter is on the input line to the differential capac= itor=20 sensor and the other on the amplified output from the sensor. The output of=20= the=20 final amplifier has a DC component with a large AC ripple on it at twice the= =20 oscillator frequency. This is applied to the inductive winding of the feedba= ck=20 coil through a parallel RC link to give a low phase error feedback sign= al.=20 If you fully smoothed the output, you would have a greater phase delay. You=20= then=20 add a low pass filter to smooth the signal for the A/D converter.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     The feedback phase delay is only a proble= m if=20 you do it this way!
> >I'm not sure about the noise. Does the VBB= =20 measure displacements in the
> >=B11 nm range?
>
>Wit= h the=20 sensor plates above, 1LSB=3D0.08nm.  But I think noise is=20 what
>determines the useful resolution.  However 0.3nm / sqrt-H= z=20 and 2.1nm RMS at
>50 SPS isn't too shabby.  It would be interes= ting=20 to assume a seismic-mass
>system and model how this would compare wi= th=20 commercial instruments and
>earth-noise models.  I'm betting it= =20 won't look so bad.
>     Have you measured your=20 environmental noise level? Is 2.1 nm a
> realistic target? The=20 amplitude of the 6 second ocean microseisms may be
> from 500 to 15= ,000=20 nm!

Actually 2.1nm was no target.  That's just what I calculat= ed=20 you could get
using the AD7745.  I agree that it is a good bit be= tter=20 than a typical home
site would justify, which is why it looked so=20 interesting.
    The lower limit for LVDT measurements is a= bout=20 0.1 nano m. With capacitative sensors you can reduce this by 100. This=20= is=20 far smaller than the background noise limits.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>  He then goes on to describe the VRDT. I suppose for th= e VBB=20 sensor this
> would greatly simplify the electronic design if one c= an=20 deal with small
> sensor gaps. I'm not sure about the noise. Does t= he=20 VBB measure
> displacements in the 1 =B1 nm range?   ---=20= Just=20 thinking out loud. I think
> it greatly depends on what type of sen= sing=20 one wants to do local,
> regional or teleseismic.
>  &nb= sp;=20    Amateur seismometers are usually limited by either microseism= s or=20
> by environmental noise - we can't usually choose a quiet remote s= ite.=20 I
> managed to reduce the noise of my LVDT to about 7 nm for a 6 mm= =20 range at
> 10 Hz, but my environmental noise is much greater than=20 this.
>
>     There are 'problems = that=20 you do not need to have' :-
>
>     The=20 velocity feedback damping does not need to be generated that=20 way!
>
>     Neither do we need to use that=20 troublesome design of capacitative sensor!
>
> =20 ***   You can use JUST position + integral current / coil feedba= ck=20 if
> you ALSO have a quad magnet + Cu plate for the velocity dampin= g!=20 Trying
> to provide velocity damping by differentiation and coil=20 feedback is
> likely to very significantly increase the overall cir= cuit=20 noise!  ***

I'm now thinking that's where I was heading, excep= t=20 for retaining the
"perpendicular" capacitance sensor. =20
    I suggest that you reconsider the capacitative=20 sensor design. You really don't need pneumatic damping problems and it is=20 helpful to be able to choose your range. If you are trying to measure a few=20 parts in a 15,000 nm signal, you need the lowest noise most linear system th= at=20 you can get. A considerable reduction in expansion coefficient is possible u= sing=20 either conducting paint, evaporated metal, or etched metal on thin pyrex she= et=20 glass. You can stick metal foil onto sheet glass with acrylic adhesive=20= -=20 don't try epoxy unless you prebake the glass to over 150 C. The electrode pl= ates=20 can be made by photo etching.
    True chopper amplifier circuits are available.=20 These are immune to 1/f noise. The SDC type sensor offers a great constructi= onal=20 advantage in ease of wiring - no electrical connections are required to the=20 seismic mass - and you can use coaxial screened cable with a charge=20 amplifier.  The design is not too critical on electrode spacing, which=20= can=20 be quite small.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Since=20 the AD7746 goes directly from
capacitance to digital, I was hoping to=20= use=20 either a PC or commercial DSP
chip or FPGA to do most of the=20 Position-Velocity derivative and other
shaping.  I like that beca= use=20 that needs minimal analog circuitry and what
you do need (integral cur= rent=20 feedback) is working at virtually DC.  And,
yes, for that to work= you=20 would need a well-damped and stable spring
mass. First-order displacem= ent=20 linearization could be done digitally.  Also you'd need to be sure th= at=20 your displacement sensor range was adequate.
    There are two problems associated with either=20 analogue or digital generation of a velocity feedback signal from a position= =20 signal. The generated signal is inherently noisy. You can also run off the e= nd=20 of the voltage or count scale --> system failure. The phase errors /= =20 delays need to be considered / compensated.
    It is relatively easy to provide a very quie= t=20 precision velocity feedback signal within the stop limits of the mass=20 movement using either magnet / coil / resistor damping or a quad magnet /=20 variable area damping plate. This uses NO external power OR electronics! Why= 'do=20 things the hard way'?
    The http://gravit= y.ucsd.edu/research/OFSEIS/opt_seis.html account=20 claims a reduction in the feedback noise using magnet / coil / resistor= =20 damping.
    24 bit DACs are available for positional feedba= ck /=20 integral feedback.
 
    Another factor which can significantly effect t= he=20 overall seismometer performance lies in the design of the suspension system,= as=20 you outlined in your rolling foil design. 
    The 'art' of being successful lies largely in n= ot=20 making mistakes and in avoiding unnecessary problems and limitations.
 
    Regards,
 
    Chris Chapman
Subject: Re: Possible that large earthquake is going to strike SISZ soon From: ian ian@........... Date: Sat, 15 Apr 2006 07:17:50 +0100 you might find that, with a large event nearby, your system will saturate - the signal level will be too great for your A/D. If you have a spare channel on your filter/amplifier you might want to connect your geophone to 2 channels, the second one having a lower gain in the hope that it will not saturate. Ian Jón Frímann wrote: >Hi all > >According to the experts at Icelandic Met Office (IMO). They think that >there is a risk of a large earthquake going to strike the SISZ (Southern >Iceland Seismic Zone) soon. They base there opinion on this data. >Yesterday there was a swarm of about 20 small earthquakes 3 km WSW of >Hveragerđi (town), all of this earthquakes where smaller then 1.0Ml in >size. They can't rule out the option that this is pre-activie of a >larger earthquake that might strike there. I assume that they draw this >from what was learned in the year 2000 in the large earthquakes that did >hit the SISZ then. There is good report on those earthquakes here >http://hraun.vedur.is/ja/skyrslur/June17and21_2000/index.html > >I wanted to let you all know of this, in case something happens. I can >forward more info on this if i learn something new. > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Possible that large earthquake is going to strike SISZ soon From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sat, 15 Apr 2006 06:50:03 +0000 Hi Ian and everybody else. > If you have > a spare channel on your filter/amplifier you might want to connect > your > geophone to 2 channels, the second one having a lower gain in the > hope > that it will not saturate. I don't have spare channel. So my system is just going to have to saturate. However i know the distance at approx, and I am less then 220 Km away from possible earthquake location. So I subspect that anything over 5.0 in mag is going to saturate my system anyway. I don't know what made experts at IMO to draw the conclutions that large earthquake is going to happen soon in that area. But I see no reasion to doubt there judgment. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Possible that large earthquake is going to strike SISZ soon From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sat, 15 Apr 2006 23:14:11 +0000 Hi all If this happens, i am going to record huge amont of earthquakes in the aftermath. Here is a map of how the earthquake activite was after the big earthquakes in the year 2000. http://hraun.vedur.is/ja/viku/2000/vika_24/index.html#mark http://hraun.vedur.is/ja/viku/2000/vika_25/index.html#mark http://hraun.vedur.is/ja/viku/2000/vika_26/index.html#mark http://hraun.vedur.is/ja/viku/2000/vika_27/index.html#mark http://hraun.vedur.is/ja/viku/2000/vika_28/index.html#mark Vika = Week Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Earthquake artical from BBC News about San Andreas Fault From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 17 Apr 2006 00:08:58 +0000 Hi all Here is a intresting artical about the San Andreas Fault and activite there. http://news.bbc.co.uk/1/hi/sci/tech/4906678.stm Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Volksmeter sensor and the AD774x CDC chip From: Larry Cochrane lcochrane@.............. Date: Tue, 18 Apr 2006 01:37:26 -0700 Hi Everyone, The discussion last week about the AD7745/6 chip was rather timely. Below is an email from Dr. Randall Peters regarding the new Analog Devices converter chip and it's use in seismology. The event files that I have been posting on the event file archive system with the file extension of *.LCTST.PSN are from the new Volksmeter sensor. If you compare the LC8 channel of my S-G sensor and the new Volksmeter sensor you will see they are similar since they both use a short period pendulum and a displacement pickup. Larry Cochrane Redwood City, PSN From Dr. Randall Peters: With the considerable recent interest expressed on the list-serve concerning Analog Devices new capacitance to digital converter chip, the AD774x; I figured it was time for me to mention the following: Two instruments using my patented (fully differential capacitive) sensor have already been outfitted with this marvelous new technology. The first was the computerized Cavendish balance sold by a physics instrument company in Michigan: http://telatomic.com/sdct1.html This instrument has been in alpha/beta test phase for about a month now, and the results look very promising. The second instrument involves my business partners Les Lazar of Zoltech Corp. ( http://zoltech.com/ ) and your own Larry Cochrane. Let me give you a little background on this instrument before discussing the details of its operation with the AD774x (x = 5 for the single channel chip and x = 6 for the dual channel chip).. This instrument, which is a conventional pendulum having a period of about 1 s, is called the Volksmeter. The name was influenced by Spiegel in Germany after a Mercer University news release following the great Andeman-Sumatra earthquake. Subsequent articles included a piece in Popular Science (April 2005), which motivated Les to contact me, expressing his wish to build the instrument. Tested first with analog electronics (using the now-defunct NE5521 integrated circuit that was developed for LVDT operation), the Volksmeter has demonstrated excellence for the detection of body waves from local earthquakes. For most, there is a surprise associated with this instrument, since the simple pendulum as a seismometer lost favor with the professional seismologists about a century ago. Based on my research activities with Jim Shirley of the Jet Propulsion Laboratory (basis for the progenitor to the Volksmeter and which responded to the tsunami-causing earthquake) I was confident that such a pendulum was useful for more than just local events (see, for example http://arxiv.org/html/physics/0508028 ). For neither Les nor myself, was our experience suited to the task of outfitting an AD7746 to the Volksmeter. But after Les contacted Larry, it became clear that we had found somebody whose experience was just of the right type. In a matter of less than two days, Larry had a single-pendulum Volksmeter operating with an AD7746 evaluation board—and even placed the instrument online, using one of his existing PIC chips.. (For those who might think the evaluation board could serve as the backbone for a practical instrument, the answer is a definite NO. The company has no intention of letting you do this, and the maximum duration of a recorded record is 8-h at the slowest sample rate (2.3 per s) permitted by their LabView generated executable—which has some bugs, as I discovered.) For those interested in watching this instrument’s capabilities, I refer you to Larry’s website at the following URL: http://seismicnet.com/quakes/images/lctst.gif The helicord record is updated every five minutes, and I noticed that just this morning (16 April) it had recorded an earthquake of magnitude 2.8 at a distance of 25.3 miles from Larry’s home where the instrument sits on a wood-over-concrete slab floor. The instrument also responded last week to teleseismic surface waves of period 16 s, from the Fiji Islands earthquake. Schedule permitting, I will plan on giving more details about the Volksmeter and some of my own research that spawned it in the weeks to come. Larry has graciously consented to ‘serve as a buffer’ for me, since in all likelihood my ‘plate is too full’ with university duties at this time to try and answer individual emails. Such mail consumes a lot of my time already; but I would like to hear from you—if you should not be offended in the event that I don’t respond quickly if at all. Randall Peters, Professor and Chairman Department of Physics Mercer University 1400 Coleman Ave. Macon, Georgia 31207 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Volksmeter sensor and the AD774x CDC chip From: ChrisAtUpw@....... Date: Tue, 18 Apr 2006 19:07:32 EDT In a message dated 18/04/2006, lcochrane@.............. writes: The discussion last week about the AD7745/6 chip was rather timely. The event files that I have been posting on the event file archive system with the file extension of *.LCTST.PSN are from the new Volksmeter sensor. If you compare the LC8 channel of my S-G sensor and the new Volksmeter sensor you will see they are similar since they both use a short period pendulum and a displacement pickup. Hi Larry, What period compensation are you claiming for this sensor? Do the plots show a compensated velocity / compensated displacement / uncompensated signal, or what? How are you performing the velocity feedback / damping necessary to stabilise the response? I note that in your SG EMail reference, you claim a flat response from 50 sec to 3 Hz, but remarked that you had to substantially increase the damping to get this. I note that in your latest circuit diagram, you seem to have greatly reduced the itegration time and wondered if the circuit values were correct? Regards, Chris Chapman
In a message dated 18/04/2006, lcochrane@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>The=20 discussion last week about the AD7745/6 chip was rather timely. The event=20 files that I have been posting on the event file archive system with the f= ile=20 extension of *.LCTST.PSN are from the new Volksmeter sensor. If you compar= e=20 the LC8 channel of my S-G sensor and the new Volksmeter sensor you will se= e=20 they are similar since they both use a short period pendulum and a=20 displacement pickup.
Hi Larry,
 
    What period compensation are you claiming for t= his=20 sensor?
    Do the plots show a compensated velocity /=20 compensated displacement / uncompensated signal, or what?
    How are you performing the velocity feedback /=20 damping necessary to stabilise the response?
 
    I note that in your SG EMail reference, you cla= im a=20 flat response from 50 sec to 3 Hz, but remarked that you had to substantiall= y=20 increase the damping to get this. I note that in your latest circuit diagram= ,=20 you seem to have greatly reduced the itegration time and wondered if the cir= cuit=20 values were correct?
 
    Regards,
 
    Chris Chapman
Subject: Re: Volksmeter sensor and the AD774x CDC chip From: Larry Cochrane lcochrane@.............. Date: Wed, 19 Apr 2006 23:40:41 -0700 Hi Chris, ChrisAtUpw@....... wrote: > > In a message dated 18/04/2006, lcochrane@.............. writes: > > The discussion last week about the AD7745/6 chip was rather timely. > The event files that I have been posting on the event file archive > system with the file extension of *.LCTST.PSN are from the new > Volksmeter sensor. If you compare the LC8 channel of my S-G sensor > and the new Volksmeter sensor you will see they are similar since > they both use a short period pendulum and a displacement pickup. > > Hi Larry, > > What period compensation are you claiming for this sensor? > Do the plots show a compensated velocity / compensated displacement > / uncompensated signal, or what? > How are you performing the velocity feedback / damping necessary to > stabilise the response? There is no period compensation in either the SG sensor or the Volksmeter (VM). Both use simple damping. The SG sensor has a feedback loop but it's just there to damp the pendulum. It might make the sensor more stable do to the feedback loop, but I'm not sure of that. The VM sensor uses eddy-current damping and has no feedback system. Randall will be sending a response to this shorty. The plots are from the raw data right out of the sensor, but with a 60 second 2 pole high-pass and 2 Hz 2 pole low-pass filter applied to the data before making the GIF image. The event files are the raw data from the AD7746 chip. > > I note that in your SG EMail reference, you claim a flat response > from 50 sec to 3 Hz, but remarked that you had to substantially increase > the damping to get this. I note that in your latest circuit diagram, you > seem to have greatly reduced the itegration time and wondered if the > circuit values were correct? Like the VM channel (LCTST) my LC8 channel is pretty much the raw data from the pickup except there are two 60 second high-pass filters in the signal path. My LC3 channel, the integrated output, should have a velocity response from about 1 second, the period of the pendulum, to about 50 seconds. I have not made any changes to my SG sensor for many years so the value of the integrator parts should be the same. -Larry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Volksmeter sensor and the AD774x CDC chip From: "ratosha morgan" morganrat@....... Date: Thu, 20 Apr 2006 14:00:36 -0400



I built a seismometer and I measured my data in currnt and time. I am trying to convert that into wavelength and oscillation. How can I do that?
From:  Larry Cochrane <lcochrane@..............>
Reply-To:  psn-l@..............
To:  psn-l@..............
Subject:  Re: Volksmeter sensor and the AD774x CDC chip
Date:  Wed, 19 Apr 2006 23:40:41 -0700
>Hi Chris,
>
>ChrisAtUpw@....... wrote:
>>
>>In a message dated 18/04/2006, lcochrane@.............. writes:
>>
>>     The discussion last week about the AD7745/6 chip was rather
>>timely.
>>     The event files that I have been posting on the event file
>>archive
>>     system with the file extension of *.LCTST.PSN are from the new
>>     Volksmeter sensor. If you compare the LC8 channel of my S-G
>>sensor
>>     and the new Volksmeter sensor you will see they are similar
>>since
>>     they both use a short period pendulum and a displacement
>>pickup.
>>
>>Hi Larry,
>>      What period compensation are you claiming for this sensor?
>
>>     Do the plots show a compensated velocity / compensated
>>displacement / uncompensated signal, or what?
>>     How are you performing the velocity feedback / damping
>>necessary to stabilise the response?
>
>There is no period compensation in either the SG sensor or the
>Volksmeter (VM). Both use simple damping. The SG sensor has a
>feedback loop but it's just there to damp the pendulum. It might
>make the sensor more stable do to the feedback loop, but I'm not
>sure of that. The VM sensor uses eddy-current damping and has no
>feedback system. Randall will be sending a response to this shorty.
>
>The plots are from the raw data right out of the sensor, but with a
>60 second 2 pole high-pass and 2 Hz 2 pole low-pass filter applied
>to the data before making the GIF image. The event files are the raw
>data from the AD7746 chip.
>
>>      I note that in your SG EMail reference, you claim a flat
>>response from 50 sec to 3 Hz, but remarked that you had to
>>substantially increase the damping to get this. I note that in your
>>latest circuit diagram, you seem to have greatly reduced the
>>itegration time and wondered if the circuit values were correct?
>
>Like the VM channel (LCTST) my LC8 channel is pretty much the raw
>data from the pickup except there are two 60 second high-pass
>filters in the signal path. My LC3 channel, the integrated output,
>should have a velocity response from about 1 second, the period of
>the pendulum, to about 50 seconds. I have not made any changes to my
>SG sensor for many years so the value of the integrator parts should
>be the same.
>
>-Larry
>
>
>
>
>__________________________________________________________
>
>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: Strange seismic signals PAB and GNI From: "Charles Spedener" charelsp@..... Date: Thu, 20 Apr 2006 23:18:31 +0200 Hi all, The elfrad group is going to discuss strange seismic signals like these ones:=20 http://www.4shared.com/file/1317969/8beb7399/oddduo.html The first is from PAB in San Pablo, Spain. This was taken on April 10, = 2006 The second is from GNI in Garni, Armenia. This was taken on April 17, = 2006 Any ideas what these signals means? Kind regards Charles -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of J=F3n Fr=EDmann Sent: Montag, 17. April 2006 02:09 To: PSN-Postlist Subject: Earthquake artical from BBC News about San Andreas Fault Hi all Here is a intresting artical about the San Andreas Fault and activite there. http://news.bbc.co.uk/1/hi/sci/tech/4906678.stm Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) ____________ Virus checked by G DATA AntiVirusKit Version: AVK 16.6885 from 18.04.2006 Virus news: www.antiviruslab.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Strange seismic signals PAB and GNI From: "Geoffrey" gmvoeth@........... Date: Thu, 20 Apr 2006 14:57:52 -0700 Is there another place to see these then this ? http://www.4shared.com/file/1317969/8beb7399/oddduo.html Servers Upgrade 4shared servers are currently undergoing maintenance. We appreciate your patience, and apologize for any inconvenience this may cause. Please contact us if you have any questions or other issues. Thank you. ----- Original Message ----- From: "Charles Spedener" To: Sent: Thursday, April 20, 2006 2:18 PM Subject: Strange seismic signals PAB and GNI Hi all, The elfrad group is going to discuss strange seismic signals like these ones: http://www.4shared.com/file/1317969/8beb7399/oddduo.html The first is from PAB in San Pablo, Spain. This was taken on April 10, 2006 The second is from GNI in Garni, Armenia. This was taken on April 17, 2006 Any ideas what these signals means? Kind regards Charles -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Jón Frímann Sent: Montag, 17. April 2006 02:09 To: PSN-Postlist Subject: Earthquake artical from BBC News about San Andreas Fault Hi all Here is a intresting artical about the San Andreas Fault and activite there. http://news.bbc.co.uk/1/hi/sci/tech/4906678.stm Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) ____________ Virus checked by G DATA AntiVirusKit Version: AVK 16.6885 from 18.04.2006 Virus news: www.antiviruslab.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Volksmeter sensor and the AD774x CDC chip From: ChrisAtUpw@....... Date: Thu, 20 Apr 2006 22:51:13 EDT In a message dated 20/04/2006, lcochrane@.............. writes: > Hi Larry, > What period compensation are you claiming for this sensor? > Do the plots show a compensated velocity / compensated displacement > / uncompensated signal, or what? > How are you performing the velocity feedback / damping necessary to > stabilise the response? There is no period compensation in either the SG sensor or the Volksmeter (VM). Both use simple damping. The SG sensor has a feedback loop but it's just there to damp the pendulum. The VM sensor uses eddy-current damping and has no feedback system. Randall will be sending a response to this shorty. The plots are from the raw data right out of the sensor, but with a 60 second 2 pole high-pass and 2 Hz 2 pole low-pass filter applied to the data before making the GIF image. The event files are the raw data from the AD7746 chip. Hi Larry, The original S/G circuit used a 62.5 sec AC coupled integrator with a gain of 10, a 1 sec low pass filter and critical damping. This was to give it an output linear with velocity. > I note that in your SG EMail reference (_http://psn.quake.net/freqtest.html_ (http://psn.quake.net/freqtest.html) ), you claim a flat response > from 50 sec to 3 Hz, but remarked that you had to substantially increase > the damping to get this. I note that in your latest circuit diagram, you > seem to have greatly reduced the itegration time and wondered if the > circuit values were correct? Like the VM channel (LCTST) my LC8 channel is pretty much the raw data from the pickup except there are two 60 second high-pass filters in the signal path. My LC3 channel, the integrated output, should have a velocity response from about 1 second, the period of the pendulum, to about 50 seconds. I have not made any changes to my SG sensor for many years so the value of the integrator parts should be the same. The circuit at _http://psn.quake.net/sg-schm.gif_ (http://psn.quake.net/sg-schm.gif) shows a 100 K Ohm input resistor, a 470 K Ohm feedback resistor and a 2 mu F parallel capacitor. This RC combination rolls off at a period of only 5.9 seconds - a factor of 10 less than we want. This is why I asked if the published circuit values are correct?? Do you still use a 4.7 M Ohm feedback resistor, like in your previous circuit at _http://psn.quake.net/sgproc.gif_ (http://psn.quake.net/sgproc.gif) ? Moreover, there does not seem to be a 1 sec low pass circuit to produce a velocity response? It is possible to ''squash'' this sort of humped response by heavy overdamping and a considerable increase in the amplifier gain, but you tend to run into serious noise problems. The original circuit used an input capacitor to the integrator, which should effectively limit the VLF 1/f noise. A 100 mu F non polar capacitor? Note that it is usually possible to lengthen the period using digital processing - if there is sufficient signal resolution, as seems likely with the VM 24 bit ADC. However, doing this to a displacement signal is likely to give rather large amplitudes at the low frequencies. Maybe the VM displacement signal could be converted into a velocity signal? Regards, Chris Chapman
In a message dated 20/04/2006, lcochrane@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>> Hi=20 Larry,
>     What period compensation are you claimin= g=20 for this sensor?
>     Do the plots show a compensate= d=20 velocity / compensated displacement
> / uncompensated signal, or=20 what?
>     How are you performing the velocity feedb= ack=20 / damping necessary to
> stabilise the response?

There is no= =20 period compensation in either the SG sensor or the Volksmeter (VM). Both u= se=20 simple damping. The SG sensor has a feedback loop but it's just there to d= amp=20 the pendulum. The VM sensor uses eddy-current damping and has no feedback=20 system.
Randall will be sending a response to this shorty.

The=20 plots are from the raw data right out of the sensor, but with a 60 second=20= 2=20 pole
high-pass and 2 Hz 2 pole low-pass filter applied to the data bef= ore=20 making the GIF
image. The event files are the raw data from the AD7746= =20 chip.
Hi Larry,
 
    The original S/G circuit used a 62.5 sec AC cou= pled=20 integrator with a gain of 10, a 1 sec low pass filter and critical damp= ing.=20 This was to give it an output linear with velocity.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     I note that in your SG EMail reference (<= A=20 href=3D"http://psn.quake.net/freqtest.html">http://psn.quake.net/freqtest.= html),=20 you claim a flat response
> from 50 sec to 3 Hz, but remarked that=20= you=20 had to substantially increase
> the damping to get this. I note tha= t in=20 your latest circuit diagram, you
> seem to have greatly reduced the= =20 itegration time and wondered if the
> circuit values were=20 correct?

Like the VM channel (LCTST) my LC8 channel is pretty much=20= the=20 raw data from the
pickup except there are two 60 second high-pass filt= ers=20 in the signal path. My LC3
channel, the integrated output, should have= a=20 velocity response from about 1 second, the period of the pendulum, to abou= t 50=20 seconds. I have not made any changes to my SG sensor for many years so the= =20 value of the integrator parts should be the same.
    The circuit at http://psn.quake.net/sg-schm.gif shows=20 a 100 K Ohm input resistor, a 470 K Ohm feedback resistor and a 2 mu F=20 parallel capacitor. This RC combination rolls off at a period of only 5.9= =20 seconds - a factor of 10 less than we want. This is why I asked if the=20 published circuit values are correct??
    Do you still use a 4.7 M Ohm feedback resistor,= =20 like in your previous circuit at http://psn.quake.net/sgproc.gif=  ?
    Moreover, there does not seem to be a 1 sec low= =20 pass circuit to produce a velocity response?
 
    It is possible to ''squash'' this sort of humpe= d=20 response by heavy overdamping and a considerable increase in the amplif= ier=20 gain, but you tend to run into serious noise problems.
    The original circuit used an input capacitor to= the=20 integrator, which should effectively limit the VLF 1/f noise. A 100 mu=20= F=20 non polar capacitor?
 
    Note that it is usually possible to length= en=20 the period using digital processing - if there is sufficient signal=20 resolution, as seems likely with the VM 24 bit ADC. However, doing this= to=20 a displacement signal is likely to give rather large amplitudes at the low=20 frequencies. Maybe the VM displacement signal could be converted into a velo= city=20 signal?
 
    Regards,
 
    Chris Chapman
Subject: My geophone did pickup mag 7.7 earthquake in siberia From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 21 Apr 2006 05:46:31 +0000 Hi all My geophone did pickup the 7.7Mw earthquake in Siberia last night. Both p and s waves are there, along with the surface wave. I will send the psn files to the event list shortly. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My geophone did pickup mag 7.7 earthquake in siberia From: Ian Smith ian@........... Date: Fri, 21 Apr 2006 07:19:15 +0100 Hi, IRIS lists it as a 6.1 but either way, it's sent out a good signal for=20 us "northerners". I was able for the first time to test my 2 gain=20 system as this quake saturated my 12 bit A/D. I've been recording on 2=20 channels for a while now (the 2nd channel having a lower gain by a=20 factor of 10) and for this trace have "stitched" the 2 files together.=20 From the 2 files I create 1 file consisting of the non-saturated high=20 gain values and the low gain values when the high gain is saturated.=20 The resultant trace is excellant and has a resolution of around 15 bits. I'll try to post it later. J=F3n Fr=EDmann wrote: >Hi all > >My geophone did pickup the 7.7Mw earthquake in Siberia last night. Both >p and s waves are there, along with the surface wave. I will send the >psn files to the event list shortly. > >Regards. > =20 > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My geophone did pickup mag 7.7 earthquake in siberia From: Ian Smith ian@........... Date: Fri, 21 Apr 2006 07:19:15 +0100 Hi, IRIS lists it as a 6.1 but either way, it's sent out a good signal for=20 us "northerners". I was able for the first time to test my 2 gain=20 system as this quake saturated my 12 bit A/D. I've been recording on 2=20 channels for a while now (the 2nd channel having a lower gain by a=20 factor of 10) and for this trace have "stitched" the 2 files together.=20 From the 2 files I create 1 file consisting of the non-saturated high=20 gain values and the low gain values when the high gain is saturated.=20 The resultant trace is excellant and has a resolution of around 15 bits. I'll try to post it later. J=F3n Fr=EDmann wrote: >Hi all > >My geophone did pickup the 7.7Mw earthquake in Siberia last night. Both >p and s waves are there, along with the surface wave. I will send the >psn files to the event list shortly. > >Regards. > =20 > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My geophone did pickup mag 7.7 earthquake in siberia From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 21 Apr 2006 07:35:44 +0000 Hi Ian I did check my record for the biggest aftershock, it was 6.3mb according to emsc-csem. I did not record that one. I have sent my traces to the psn event file list. The P wave is clear in the recording, but it is alot harder to see the S wave. Surfaces waves appear also, good enugh to be seen. I did lowpass filter the event files to 1Hz to see the signal clear enugh. But anything above that didn't show it. This earthquake is the biggest one I have recorded so far. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fwd: Force Feedback From: Larry Cochrane lcochrane@.............. Date: Fri, 21 Apr 2006 00:53:07 -0700 From Dr. Randall Peters.... There is this myth that the only way to see teleseismic events is by working with a long period instrument in which the characteristics are governed by force feedback. Why the myth has persisted for so long remains a mystery to me, as I now explain. The response of a seismometer involves the convolution of two parts: (i) the mechanical, and (ii) the electronics. When electronics wasn’t very good, the obvious thing to do was ‘wring every ounce’ of performance out of the mechanical parts. Now that the electronics is much better understood than the mechanical characteristics (because of complex internal friction—concerning which I am an internationally recognized expert), a paradigm shift is called for. It’s not an easy shift for people who are steeped in the tradition that has ruled now for many decades. The LaCoste spring instrument was an example of a major mechanical improvement over previous vertical seismometer designs. Before the use of capacitive sensors, force feedback was not employed, since the Faraday law (velocity) detectors that were employed, still functioned well over a large mechanical range. All that changed with the introduction of gap-varying capacitive sensors. Their mechanical range is so small that force balance became necessary. I see force balance as something of a mix of better electronics, but having mechanical properties not much better than the situation before LaCoste’s contribution. Force-balance has been built around fairly-early-generation solid state, analog electronics (now more than twenty years old). The mix has yielded an outstanding but complicated (expensive) instrument for earthquake detection. When it comes to frequencies below about 10 mHz, however, I predict that the Volksmeter that Larry has online (having a period of about 1 s and no feedback whatsoever) will outperform the $50K instruments, when it comes to the matter of studying low frequency earth motions. (In a later note I will explain why the response of conventional force-balance instruments below their lower corner frequency is a disaster. It’s tantamount to operating an oscilloscope in the a.c. coupled mode, when d.c. coupling is called for.) The Volksmeter (VM) doesn’t need feedback This designer doesn’t even want to ever consider feedback! Yes, feedback would improve the appearance of teleseismic surface waves in the VM raw data displayed by the helicord being generated by Larry Cochrane. But it is not necessary. Once a teleseismic event has been observed above noise in the helicord (if not observed, it probably would not have been readily seen even with feedback), it is a simple matter with the WinQuake software to ‘present that earthquake’ to the world in the form with which the world is accustomed to ‘viewing earthquake records’. All that is necessary, after having downloaded the pertinent segment, is to (i) do a high pass filter whose cutoff is just below the lowest frequency component of the surface waves, and then (ii) integrate the filtered result, using Larry’s “I” button. What is immediately displayed is a nearly ‘flat to velocity’ record, the display choice to which seismology became long ago addicted (apparently in large measure because of Faraday law detectors). I just heard from Larry today that he is planning to provide a channel in addition to lctst, which is the output from our displacement (d.c. position) detector, whose attenuation is proportional to frequency squared below about 1 Hz). This new channel will be a filtered/integrated output of the lctst signal; i.e., a ‘velocity’ output. With it, teleseismic events should be more readily observed, whereas the still-present ‘mother signal’ lctst will still be available as a superior channel for purpose of local, higher frequency events. Thus we will have something very similar to the two channels of lc8 and lc3—output from Larry’s Shackelford-Gunderson (SG) seismometer. Though it was many years ago, the amateur messrs S & G were ‘right on target’ with their approach—using an ordinary pendulum with the best electronics available to them at the time. The reason this simple filter/integrate operation works so surprisingly well (nearly as good as force balance at a very, very small fraction of the cost and complexity) has to do with the nature of the Volksmeter’s (i) pendulum, and (ii) sensor. Insofar as the viscous damped, driven harmonic oscillator as an approximation to the behavior of a seismometer is concerned, the pendulum is the best candidate having some chance of being adequately described by it (the model everybody uses, even for the many cases where it is inappropriate). When the frequency of drive is below the natural frequency of the pendulum (which for the VM is eddy-current damped near critical using a rare earth magnet sub-assembly), the transfer functions falls off as frequency squared. (Velocity detectors below their lower corner fall off even faster, as frequency cubed, expressed relative to displacement). The quadratic in frequency falloff of the VM in this region, means that the signal for teleseismic surface waves corresponds to what is called ‘acceleration response’. Actually, every seismometer responds only to acceleration and NOTHING else. ( I will address this in a later note—even plan to write an article titled “Seismometer physics for dummies”.) Because the VM sensor output is one of position, the integral of the teleseismic filtered signal is a decent approximation to ground velocity. I have satisfied myself concerning this approximation by looking at the Fiji Islands earthquake and comparing the integration result against artifacts that were shown by modeling to be possible, due to transients. For those who should employ this ‘trick’, keep in mind that the spectral components way below periods of about 15 s (which are present in the VM output if not high-pass filtered) can generate huge artifacts. Also, before doing Larry’s FFT, which does not use apodization (such as a Hanning window, for which I am glad), a high pass filter is necessary before the spectrum is meaningful. I am pleased with what I’ve seen in this method, and to make the earthquake signal comply more perfectly with signals generated by the Global Seismographic Network’s broadband $50 K instruments -- would require a deconvolution based on the FFT. I doubt that anybody is interested in ‘going there’. I need to point out something concerning the ‘drift’, as some might label the secular component of the output from the VM. Yes, this can result largely from electronics instability, due to the thermal coefficient of the AD774x . But don’t be too hasty to pigeon-hole everything into that category. Operated in a reasonably isothermal environment, these slowly changing features are the basis for the very (earth-related) dynamics for which the VM will shine. For those interested only in earthquakes, this secular trend can be easily removed with a simple recursive filter, as Larry already does before posting lctst on seismicnet. In my planned ‘dummies’ article I will try to help people understand, on the basis of the simple RC network, the infinite impulse response filters (esoteric world of digital signal processing (DSP), based on the formidable Z-transform—a discrete form of the Laplace transform, with which all electrical engineers are trained; which is more general (but less numerically powerful) than the Fourier transform, with which all physicists are trained—last one being the basis for the remarkable ‘fast version’ FFT, wonderfully embedded within Larry’s Winquake) The transfer function of the pendulum has no frequency dependence whatsoever when it comes to one of the two forms of acceleration to which it responds—that of tilt. Tilt acceleration is nothing other than the component of the earth’s field that is perpendicular to the direction in which an object falls. Einstein’s famous theories of relativity say that we cannot (local observation) tell the difference between this acceleration and horizontal ground acceleration devoid of tilt. For whatever reason, I appear to be the only person to have ever recognized what a marvelous opportunity this ‘tilt’ business is for purpose of studying the standing wave oscillations (hum) of the earth. The VM mechanical response is ‘flat to tilt displacement’, and global standing waves of the earth cause the direction of ‘little g’ to change at nrad levels for many such oscillations (for an instrument positioned somewhere along a nodal line). Thus the VM is the obvious, inexpensive means to study something that has mainly eluded the herculean efforts of some scientists who have become very much interested in earth hum. I was a participant in the IRIS Broadband Workshop concerned with extending the low-frequency response of seismic instruments. I am confident that the VM is an instrument that should be of interest to those who organized the conference, yet there is reluctance on their part to believe that something so simple (and cheap) as the VM could be of any real value to them. I hope that I can motivate some of you in the amateur community to participate with me in such studies. I have just become aware of some recent questions about the VM, to which I now respond. Seismometers with mechanical amplification are inherently ‘unstable’ and require force-balance when operating with gap-varying capacitive sensors. The biggest culprit is the temperature coefficient of the modulus of the spring constant. This is typically much worse than effects dues to the thermal coefficient of expansion differences between dissimilar materials. When constructed to provide inherent ‘gain’ by period lengthening, mechanical oscillators become not only more sensitive to earthquakes—but also more sensitive to the myriad problems associated with creep in their structures. My career has been devoted to the study of these problems (friction at the mesoscale) and I will in due time discuss some of its features with readers if they are interested. I have worked with many different forms of capacitive detectors. My PhD research used a gap varying transducer (non-differential) to measure harmonic distortion of 30 MHz longitudinally polarized ultrasonic (acoustic) waves in copper single crystals as a function of temperature—distortion due to the interatomic anharmonic (nonlinear) potential. Using a boxcar integrator this sensor could easily measure displacements less than 0.1 nm (1 Angstrom for you old-timers). For some purposes, these gap-varying sensors are without equal in terms of sensitivity, particularly if one uses cryogenic amplifiers as was done by some Russians in the late 1960’s—to get resolutions approaching nuclear dimensions (100,000 times smaller). Their biggest problem, when it comes to use in seismometers, is that the gap-varying capacitor is very much less versatile than the area-varying type that I have patented. The sensitivity of a single-element of one of my area-varying (first) fully-differential capacitive sensors does not compete favorably with the best gap-varying types. But when configured as an array, enormous mechanical dynamic range (as compared to the gap-varying units) is still possible without the sensitivity being inadequate. I will in due time also explain this to readers who are interested. The simple pendulum is without a doubt the most stable of all seismic instruments. Historically, it was one of the first seismographs, and it remains the instrument against which ‘sophisticated’ seismometers are compared—always, it seems, with an accompanying statement that the ordinary pendulum is not good enough for ‘real’ work because the period of an ‘acceptably small’ instrument is always too short for ‘adequate’ sensitivity.. When the pendulum operates with the ‘right’ sensor and electronics, none of this conventional rhetoric remains appropriate As compared to ‘unstable’ conventional instruments, the VM is exquisitely ‘stable’. I use quotes here because at the nm and smaller level there is no such thing as a truly static system. Indeed stress is always present and there is no level below which creep does not occur. Where we hope to eventually operate seismographs reliably, creep is not even ‘smooth’ and its ‘snap, crackle, and pop’ (the Portevin LeChatelier effect) are the nemesis of long-period seismometers. For too many years now, in the compromise between deficiencies of (i) electronics and (ii) mechanical structures, the emphasis was on trying to improve the mechanical. It is time to return to the simplest mechanical structure (pendulum) and ‘wring from the electronics’ (augmented by numerical methods such as Larry is planning) everything that the electronics can be (to use an army expression). To me, the award winning AD774x is a brand new, wonderful technology. I am delighted to have the apparent opportunity to work with talented amateur seismologists. I see us having the opportunity to become first in the world to show even the pro’s a thing or two. I expect that a collective effort, centered around this new chip, will result in discoveries of importance to the world of geoscience. I want everybody to rest assured that I have no intention of trying to ‘hog the glory’ that might result from such discovery. From what I’ve so far seen, I admire greatly the attributes of various individuals in this amateur community; and it is my promise to give you credit where it is due. (In the mountain country where I come from, a man is no better than his word. If you find me at anytime deviating from this promise, then broadcast the evidence for my transgression to the whole world by means of the list-serve.) Randall Peters PhD __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My geophone did pickup mag 7.7 earthquake in siberia From: Dave Nelson davenn@............... Date: Sat, 22 Apr 2006 11:18:04 +1000 Hi Ian the mainshock was adjusted down from M7.7 to 7.6 there were 2 x M6.1 aftershocks amongst dozens of other smaller ones Dave N At 07:19 AM 21/04/2006 +0100, you wrote: >Hi, >IRIS lists it as a 6.1 but either way, it's sent out a good signal for us >"northerners". I was able for the first time to test my 2 gain system as >this quake saturated my 12 bit A/D. I've been recording on 2 channels for >a while now (the 2nd channel having a lower gain by a factor of 10) and >for this trace have "stitched" the 2 files together. From the 2 files I >create 1 file consisting of the non-saturated high gain values and the low >gain values when the high gain is saturated. The resultant trace is >excellant and has a resolution of around 15 bits. > >I'll try to post it later. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.1.385 / Virus Database: 268.4.5/321 - Release Date: 21/04/2006 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Hayward Fault geometry... From: "Kareem" system98765@............. Date: Fri, 21 Apr 2006 22:57:25 -0700 Where can I find very comprehensive information on the trajectory of the Hayward Fault where the dip is illustrated? I'm looking specifically for the Hayward Fault area between San Pablo Bay and Oakland area. I would like to know if this strike slip fault has a 30 degree dip or any at all in the specified area. I've done a number of searches online but couldn't find anything useful. from: Kareem Lanier El Sobrante, California ------------------------------------------ www.heyjoojoo.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My geophone did pickup mag 7.7 earthquake in siberia From: ian ian@........... Date: Sat, 22 Apr 2006 07:36:57 +0100 Hi, IRIS has something wrong with it at the moment which is why I thought it was only a 6 magnitude. http://www.emsc-csem.org/index.php?page=current&sub=list&view=2 is showing 7.7, though Dave points out that this is now 7.6. The first file I uploaded somehow hadn't had the cat trimmed off of it which (luckily) jumped onto the enclosure about 30 minutes before the quake. I have since sent in a corrected version with the cat chopped off! http://www.webtronics.com/cgi-dos/makegif.exe?/quakes/0604/060421.002544.hd0.psn Well done for your geophone. Cheers Ian Jón Frímann wrote: >Hi Ian > >I did check my record for the biggest aftershock, it was 6.3mb according >to emsc-csem. I did not record that one. I have sent my traces to the >psn event file list. The P wave is clear in the recording, but it is >alot harder to see the S wave. Surfaces waves appear also, good enugh to >be seen. I did lowpass filter the event files to 1Hz to see the signal >clear enugh. But anything above that didn't show it. > >This earthquake is the biggest one I have recorded so far. > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My geophone did pickup mag 7.7 earthquake in siberia From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sat, 22 Apr 2006 09:13:49 +0000 Hi I did clean the file of any frequnacy above 1Hz, becose of local noise that was in the recording on higer frequancyes. I was not expecting that to be able to detect earthquake at this distance. Since my geophone is short period and not ment for this type of event at this distnace. I know that I can detect earthquakes that are at the distance of ~860km and around size mag 4.6 - 5.0 at that range. So far, emsc-csem says the earthquake is 7.7Mw. Regards. Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Siberia 7.6 on an FMES From: Angel sismos@.............. Date: Sat, 22 Apr 2006 10:06:08 +0000 Hi All, Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer. http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg Each line is 30 minutes long. FMES's are easy to build and are great for tele-seismic stuff and pretty good for the local events also. regards, Angel Saturday, April 22, 2006, 9:13:49 AM, you wrote: > Hi > I did clean the file of any frequnacy above 1Hz, becose of local noise > that was in the recording on higer frequancyes. > I was not expecting that to be able to detect earthquake at this > distance. Since my geophone is short period and not ment for this type > of event at this distnace. I know that I can detect earthquakes that are > at the distance of ~860km and around size mag 4.6 - 5.0 at that range. > So far, emsc-csem says the earthquake is 7.7Mw. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Siberia 7.6 on an FMES From: "jimo17@......... jimo17@juno.com Date: Sat, 22 Apr 2006 11:09:06 GMT what is a FMES-???? I broke my right hand so am typing left-handed...jim -- Angel wrote: Hi All, Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer. http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg Each line is 30 minutes long. FMES's are easy to build and are great for tele-seismic stuff and pretty good for the local events also. regards, Angel Saturday, April 22, 2006, 9:13:49 AM, you wrote: > Hi > I did clean the file of any frequnacy above 1Hz, becose of local noise= > that was in the recording on higer frequancyes. > I was not expecting that to be able to detect earthquake at this > distance. Since my geophone is short period and not ment for this type= > of event at this distnace. I know that I can detect earthquakes that a= re > at the distance of ~860km and around size mag 4.6 - 5.0 at that range.= > So far, emsc-csem says the earthquake is 7.7Mw. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: What is an FMES From: Angel sismos@.............. Date: Sat, 22 Apr 2006 12:04:39 +0000 Hello Jim, An FMES is a bunch of plumbing filled with water. Well, that is a bit over simplified but no too much. Fluid Mass Electrolytic Seismometer. Once you have the knack of it you can make one in just a few hours, not counting the electronics. With just your left hand it might take you a bit longer. Basically two transducer about a meter apart joined by some tubing so the electrolytic fluid (water and antifreeze) find a level within the transducers. The transducers form part of a sensitive resistive bridge which senses the motion of the fluid. Like I said this is over simplified but not by far. There is a yahoo group that chats now and then on building them and trading ideas, you can see some photos at the groups site: http://groups.yahoo.com/group/fmes/ Dave Nelson is the creator of FMES and he might pipe (no pun intended) in and say a bit more. Dave might have some more current pictures. angel Saturday, April 22, 2006, 11:09:06 AM, you wrote: > what is a FMES-???? > I broke my right hand so am typing left-handed...jim > -- Angel wrote: > Hi All, > Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in > Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer. > http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg > Each line is 30 minutes long. > FMES's are easy to build and are great for tele-seismic stuff and > pretty good for the local events also. > regards, > Angel > Saturday, April 22, 2006, 9:13:49 AM, you wrote: >> Hi >> I did clean the file of any frequnacy above 1Hz, becose of local noise >> that was in the recording on higer frequancyes. >> I was not expecting that to be able to detect earthquake at this >> distance. Since my geophone is short period and not ment for this type >> of event at this distnace. I know that I can detect earthquakes that are >> at the distance of ~860km and around size mag 4.6 - 5.0 at that range. >> So far, emsc-csem says the earthquake is 7.7Mw. > __________________________________________________________ > 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. -- Best regards, Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sat, 22 Apr 2006 13:19:57 +0000 Hi all The eastern Skaftarkatli has erupted and has created a glacial outburst flood. It has reached low level lands. It has already reached the town Kirkjubćjarklaustur (the town is save, no worryes about that), but Skaftá river flows close by it. It is expected that the glaciar outburst flood is expected to reach it's peak in a two days time. It is also expected that this is going to be rather big flood. Last flood there was in August last year. Following that flood there was an event of harmonic tremor, that did last for about ~12 hours. Such event is problay going to follow this glaciar outburst flood. This flood also opens up the possibliti of a eruption in the volcano that is under the ice there, but the volcano is often called "Hamarinn", is in the Bardarbunga volcano rupture zone. But the eruption is possible becose of the pressure change that happens on top of the volcano. In the year 2004, the trigger for the eruption in Grimsfjall caldera was a flood that did start two days earlyer. I do not know for sure if the harmonic tremor are going to show up on my geophone, but given that harmonic tremor frequancy is from 0.5Hz up to 60Hz (maybe higer) it is possible that i might see the harmonic tremor. This harmonic tremor problay won't happen after one or three days from now, but i am unsure of that time estimate that i have. I am just going to have to wait and see. I can replay more info for those who are intrested. But i am waiting for more news on this and on what exacly is happening. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Siberia 7.6 on an FMES From: "Erich Kern" efkern@............. Date: Sat, 22 Apr 2006 10:38:14 -0700 Wow Angel!! That is a very good clean recording, and I'm amazed at the sensitivity and low noise level. Is your FMES in a vault? Regards, Erich ----- Original Message ----- From: "Angel" To: "Jón Frímann" Sent: Saturday, April 22, 2006 3:06 AM Subject: Siberia 7.6 on an FMES Hi All, Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer. http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg Each line is 30 minutes long. FMES's are easy to build and are great for tele-seismic stuff and pretty good for the local events also. regards, Angel Saturday, April 22, 2006, 9:13:49 AM, you wrote: > Hi > I did clean the file of any frequnacy above 1Hz, becose of local noise > that was in the recording on higer frequancyes. > I was not expecting that to be able to detect earthquake at this > distance. Since my geophone is short period and not ment for this type > of event at this distnace. I know that I can detect earthquakes that are > at the distance of ~860km and around size mag 4.6 - 5.0 at that range. > So far, emsc-csem says the earthquake is 7.7Mw. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Siberia 7.6 on an FMES From: apsn apsn@........... Date: Sat, 22 Apr 2006 09:48:29 -0800 I agree with Erich, the record from your FMES is=20 outstanding, Angel. I need to build one=20 asap. Any information on how to do so or did you=20 already give that and I missed it? Bob PSN-Alaska http://apsn.awcable.com At 09:38 AM 4/22/2006, you wrote: >Wow Angel!! That is a very good clean recording,=20 >and I'm amazed at the sensitivity and low noise level. Is your FMES in >a vault? > >Regards, > >Erich > > >----- Original Message ----- >From: "Angel" >To: "J=F3n Fr=EDmann" >Sent: Saturday, April 22, 2006 3:06 AM >Subject: Siberia 7.6 on an FMES > > >Hi All, > >Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in >Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer. > >http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg > >Each line is 30 minutes long. > >FMES's are easy to build and are great for tele-seismic stuff and >pretty good for the local events also. > >regards, > >Angel > > >Saturday, April 22, 2006, 9:13:49 AM, you wrote: > > > Hi > > > I did clean the file of any frequnacy above 1Hz, becose of local noise > > that was in the recording on higer frequancyes. > > > I was not expecting that to be able to detect earthquake at this > > distance. Since my geophone is short period and not ment for this type > > of event at this distnace. I know that I can detect earthquakes that are > > at the distance of ~860km and around size mag 4.6 - 5.0 at that range. > > > So far, emsc-csem says the earthquake is 7.7Mw. > >__________________________________________________________ > >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: What is an FMES From: Barry Lotz barry_lotz@............. Date: Sat, 22 Apr 2006 14:10:08 -0700 (PDT) Hi Angel/ Dave I tried to look at the photos w/o success ????. I remembered a Scientific American amateur Scientist artical of 11/1973 which showed a sensitive tilt meter construction ( with Mercury however.) which used capacitive sensors at the ends. Is it similar to yours? While I was blowing the dust of the old issues I ran across the SG seismometer 9/1975 article. This is what started me down the amateur seismologist path. Regards Barry Angel wrote: Hello Jim, An FMES is a bunch of plumbing filled with water. Well, that is a bit over simplified but no too much. Fluid Mass Electrolytic Seismometer. Once you have the knack of it you can make one in just a few hours, not counting the electronics. With just your left hand it might take you a bit longer. Basically two transducer about a meter apart joined by some tubing so the electrolytic fluid (water and antifreeze) find a level within the transducers. The transducers form part of a sensitive resistive bridge which senses the motion of the fluid. Like I said this is over simplified but not by far. There is a yahoo group that chats now and then on building them and trading ideas, you can see some photos at the groups site: http://groups.yahoo.com/group/fmes/ Dave Nelson is the creator of FMES and he might pipe (no pun intended) in and say a bit more. Dave might have some more current pictures. angel Saturday, April 22, 2006, 11:09:06 AM, you wrote: > what is a FMES-???? > I broke my right hand so am typing left-handed...jim > -- Angel wrote: > Hi All, > Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in > Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer. > http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg > Each line is 30 minutes long. > FMES's are easy to build and are great for tele-seismic stuff and > pretty good for the local events also. > regards, > Angel
Hi Angel/ Dave
  I tried to look at the photos w/o success ????. I remembered a Scientific American amateur Scientist artical of 11/1973 which showed a sensitive tilt meter construction ( with Mercury however.) which used capacitive sensors at the ends. Is it similar to yours? While I was blowing the dust of the old issues I ran across the SG seismometer 9/1975 article. This is what started me down the amateur seismologist path.
Regards
Barry

Angel <sismos@..............> wrote:
Hello Jim,

An FMES is a bunch of plumbing filled with water. Well, that is a bit over
simplified but no too much. Fluid Mass Electrolytic Seismometer. Once
you have the knack of it you can make one in just a few hours, not
counting the electronics. With just your left hand it might take you a
bit longer.

Basically two transducer about a meter apart joined by some tubing so
the electrolytic fluid (water and antifreeze) find a level within the
transducers. The transducers form part of a sensitive resistive bridge
which senses the motion of the fluid. Like I said this is over
simplified but not by far.

There is a yahoo group that chats now and then on building them and
trading ideas, you can see some photos at the groups site:

http://groups.yahoo.com/group/fmes/

Dave Nelson is the creator of FMES and he might pipe (no pun intended)
in and say a bit more. Dave might have some more current pictures.

angel



Saturday, April 22, 2006, 11:09:06 AM, you wrote:

> what is a FMES-????
> I broke my right hand so am typing left-handed...jim

> -- Angel wrote:
> Hi All,

> Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in
> Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer.

> http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg

> Each line is 30 minutes long.

> FMES's are easy to build and are great for tele-seismic stuff and
> pretty good for the local events also.

> regards,

> Angel





Subject: Re[2]: Siberia 7.6 on an FMES From: Angel sismos@.............. Date: Sat, 22 Apr 2006 21:59:35 +0000 Hello Erich and Bob, Thanks, but all of the credit goes to Dave Nelson for dreaming up the idea and spending countless hours on this project. That particular FMES is in a vault and I live in a generally quite place. The vault is about 60 yards from the house and I get the signal to the house via TCP/IP. The digitizer is a single channel 24 bit $150 device from www.symres.com which goes into an Earthworm transport buffer and then published on the internet. My other FMES's are on a WinSDR system. I must add that my Winsdr board also exports to an Earthworm system. In its most simple from and FMES can be built in an afternoon with stuff you can get a hardware store. The fluid is made conductive with distilled water a .5% antifreeze and .1% anti-foam (Rug Doctor fluid). http://www.volcanbaru.com/fmes/an_fmes.JPG a newer model http://www.volcanbaru.com/fmes/a_Tranducer.JPG Transducer end http://www.volcanbaru.com/fmes/coner_of_shop.JPG corner of my shop an FMES is under the table under the silver foam insulation box http://www.volcanbaru.com/fmes/Electronics_stack.JPG Dave elelctronics, the schematics and board files are available. The LED make setup a snap. http://www.volcanbaru.com/fmes/fmes_angel.JPG new FMES on the work table http://www.volcanbaru.com/fmes/fmes_angel2.JPG more of the above http://www.volcanbaru.com/fmes/fmes_base.JPG Dave style base http://www.volcanbaru.com/fmes/fmes_parts.JPG Early FMES, they work real well and is made from hardware store stuff http://www.volcanbaru.com/fmes/fms65.JPG an FMES in my vault http://www.volcanbaru.com/fmes/internal_and_external_electrodes.JPG Electrode parts before assembly http://www.volcanbaru.com/fmes/mexico_1_4.jpg mexico jan 4 on early fmes 60 minute time scale http://www.volcanbaru.com/fmes/Pinch_valve.JPG pinch valve, no longer used http://www.volcanbaru.com/fmes/sandwich.jpg Sandwich Island quake and a little local event on first line and a bit of noise on the second line. 120 minutes per line http://www.volcanbaru.com/fmes/Transducer_detail.JPG Transducer parts http://www.volcanbaru.com/fmes/Transducer_end.JPG Assembles transducer http://www.volcanbaru.com/fmes/transducer_detai3.JPG more transducer details http://www.volcanbaru.com/fmes/transducer_detail2.JPG more detail http://www.volcanbaru.com/fmes/tube_valve.JPG restriction detail http://www.volcanbaru.com/fmes/two_traces.jpg my broadband top lineand the FMES on the bottom line http://www.volcanbaru.com/fmes/vault2.JPG BB and FMES in my vault I am sure that there are hundreds of ways to configure an FMES, these just a few. I will be on vacation for the next three weeks (starting the 28th) but will be but will try to check my mail and will be glad to help anyone get one of these going. I am sure that Dave will help also. I will try to write a bit more after dinner. I talked to Dave and he is going to pipe in. Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Calif--100th Anniversary From: "Connie and Jim Lehman" lehmancj@........... Date: Sat, 22 Apr 2006 22:39:48 -0400 Thanks Steve, Larry, Richard, John & Jan for arranging the informal PSN = get-together Tues. eve. We enjoyed several field trips as well as = several technical sessions during the week. Best wishes in keeping the = PSN vision alive and well.. Jim=20
Thanks Steve, Larry, Richard, = John &=20 Jan for arranging the informal PSN get-together Tues. eve.  We = enjoyed=20 several field trips as well as several technical sessions during the = week. =20 Best wishes in keeping the PSN vision alive and well..   Jim=20
Subject: Re: Calif--100th Anniversary From: John or Jan Lahr johnjan@........ Date: Sat, 22 Apr 2006 22:37:28 -0700 I've posted some pictures of the PSN meeting here: http://jclahr.com/psn/ The Seismological Society of America meeting was quite interesting. For me the highlights were seeing the fence near Crystal Springs Reservoir that was offset by the 1906 earthquake and seeing the retrofit of the Oakland City Hall -- it's now resting on huge rubber pads that provide base isolation. Cheers, John At 07:39 PM 4/22/2006, you wrote: >Thanks Steve, Larry, Richard, John & Jan for arranging the informal >PSN get-together Tues. eve. We enjoyed several field trips as well >as several technical sessions during the week. Best wishes in >keeping the PSN vision alive and well.. Jim __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Volksmeter sensor and the AD774x CDC chip From: Larry Cochrane lcochrane@.............. Date: Sun, 23 Apr 2006 02:01:24 -0700 Hi Chris, ChrisAtUpw@....... wrote: > Hi Larry, > > The original S/G circuit used a 62.5 sec AC coupled integrator with > a gain of 10, a 1 sec low pass filter and critical damping. This was to > give it an output linear with velocity. > > > I note that in your SG EMail reference > (http://psn.quake.net/freqtest.html), you claim a flat response > > from 50 sec to 3 Hz, but remarked that you had to substantially > increase > > the damping to get this. I note that in your latest circuit > diagram, you > > seem to have greatly reduced the itegration time and wondered if the > > circuit values were correct? > > Like the VM channel (LCTST) my LC8 channel is pretty much the raw > data from the > pickup except there are two 60 second high-pass filters in the > signal path. My LC3 > channel, the integrated output, should have a velocity response from > about 1 second, the period of the pendulum, to about 50 seconds. I > have not made any changes to my SG sensor for many years so the > value of the integrator parts should be the same. > > The circuit at http://psn.quake.net/sg-schm.gif shows a 100 K Ohm > input resistor, a 470 K Ohm feedback resistor and a 2 mu F parallel > capacitor. This RC combination rolls off at a period of only 5.9 seconds > - a factor of 10 less than we want. This is why I asked if the published > circuit values are correct?? > Do you still use a 4.7 M Ohm feedback resistor, like in your > previous circuit at http://psn.quake.net/sgproc.gif ? > Moreover, there does not seem to be a 1 sec low pass circuit to > produce a velocity response? > > It is possible to ''squash'' this sort of humped response by heavy > overdamping and a considerable increase in the amplifier gain, but you > tend to run into serious noise problems. > The original circuit used an input capacitor to the integrator, > which should effectively limit the VLF 1/f noise. A 100 mu F non polar > capacitor? I still use a 4.7M feedback resistor and a 2.2UF cap. There is a 60 second high-pass filter before the integrator to limit the low frequencies and DC offset going into the integrator. > > Note that it is usually possible to lengthen the period using > digital processing - if there is sufficient signal resolution, as seems > likely with the VM 24 bit ADC. However, doing this to a displacement > signal is likely to give rather large amplitudes at the low frequencies. > Maybe the VM displacement signal could be converted into a velocity signal? Remember that a pendulum with a displacement pickup will act as an accelerometer below the period of the pendulum, so both the SG and the new VM sensor are recording acceleration for teleseismic events. The integrator, in the SG sensor electronics (my LC3 channel), should be producing a velocity signal. I should be able to do the same thing in WinSDR by digitally integrating the acceleration signal from the VM sensor. Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 23 Apr 2006 09:41:18 +0000 Hi all For the first time, i can smell a solfourdyoxisde (i don't remember how it is spelled) that comes from this glaciar outburst flood coming from Vatnajokull. The smell is bad. This smell is also felt on most of the Northen part of Iceland, but the wind is SE at the moment. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: ian ian@........... Date: Sun, 23 Apr 2006 10:54:17 +0100 probably sulphur dioxide, or VOG in Hawaii. The usual advice is close the windows and no vigorous outdoor activity, particularly for children. Cheers Ian Jón Frímann wrote: >Hi all > >For the first time, i can smell a solfourdyoxisde (i don't remember how >it is spelled) that comes from this glaciar outburst flood coming from >Vatnajokull. The smell is bad. This smell is also felt on most of the >Northen part of Iceland, but the wind is SE at the moment. > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 23 Apr 2006 10:14:21 +0000 Hi I don't think that this sulphur dioxide is at dangerus levels, the source is ~150km away from my location. But the smell is awful. The wind is strong at my location, it is expected to stay strong today. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: ian ian@........... Date: Sun, 23 Apr 2006 11:19:53 +0100 I think the rule of thumb is that if the smell is "awfull" then (simple) precautions should be taken. When in Hawaii, I remeber that a day of VOG would give me sensation in my chest - presumably lungs. You could usually see it too as a very slight haze, hence the name VOG - volcanic fog. Cheers Ian Jón Frímann wrote: >Hi > >I don't think that this sulphur dioxide is at dangerus levels, the >source is ~150km away from my location. But the smell is awful. The wind >is strong at my location, it is expected to stay strong today. > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 23 Apr 2006 11:01:38 +0000 Hi When i ment awfull, i didn't mean it was strong. But since i did send the first email, the wind appears to have changed. Since the smell is gone for the moment. It might return if the wind direction changes agen. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 23 Apr 2006 12:38:05 +0000 Hi all According to the news the flood is still growing. There are also appearing harmonic tremors on the Icelandic Met Office seismometer at this moment. That indicates that there is something going on in Vatnajokull at the moment. The harmonic tremors are belived to come from water that is under pressure and is cracking the glacier. This progress is also releasing sulphur dioxide into the air. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 23 Apr 2006 12:57:00 +0000 Hi all Here are some statics about this flood. I did forget to send in my previus post. At this moment (12:47 UTC, 23.04.2006) this is amount of water that is coming down the river skafta. The statics are from a place called Asa Eldvatn in Skafta. Based on the latest data i can find. ~620m3/s is amount of water flowing, the higt is ~465 cm. But at other locations, it is over 3 meterers and has overflooded a flood barrier. No house are belived in danger at this moment. Sorry for the spelling errors. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatlieastern From: "Dave Nelson" davefnelson@....... Date: Sun, 23 Apr 2006 08:07:09 -0700 ----- Original Message ----- From: "Jón Frímann" To: Sent: Sunday, April 23, 2006 04:01 Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatlieastern > Hi > > When i ment awfull, i didn't mean it was strong. But since i did send > the first email, the wind appears to have changed. Since the smell is > gone for the moment. It might return if the wind direction changes agen. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > 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: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 23 Apr 2006 22:17:06 +0000 Hi all The glacial flood has reahced it's max, did so around 12:00 today according to mesurments. Since then it has been dropping slowly. Now the real intresting part. Is the pressure drop in the Hamarinn volcano (far as i can tell, i think it is this one here http://www.volcano.si.edu/world/volcano.cfm?vnum=1703-02= ) is going to start a eruption, it might not happen, but it might happen, it's a 50/50 chance. I expect that harmonic tremors are going to appear soon, but that is unceartin factor also. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Volksmeter sensor and the AD774x CDC chip From: ChrisAtUpw@....... Date: Sun, 23 Apr 2006 22:36:00 EDT In a message dated 23/04/2006, lcochrane@.............. writes: > Like the VM channel (LCTST) my LC8 channel is pretty much the raw > data from the pickup except there are two 60 second high-pass filters in the > signal path. My LC3 channel, the integrated output, should have a velocity >response from about 1 second, the period of the pendulum, to about 50 seconds. I > have not made any changes to my SG sensor for many years so the > value of the integrator parts should be the same. > > The circuit at http://psn.quake.net/sg-schm.gif shows a 100 K Ohm > input resistor, a 470 K Ohm feedback resistor and a 2 mu F parallel > capacitor. This RC combination rolls off at a period of only 5.9 seconds > - a factor of 10 less than we want. > Do you still use a 4.7 M Ohm feedback resistor, like in your > previous circuit at http://psn.quake.net/sgproc.gif ? > Moreover, there does not seem to be a 1 sec low pass circuit to > produce a velocity response? I still use a 4.7M feedback resistor and a 2.2UF cap. There is a 60 second high-pass filter before the integrator to limit the low frequencies and DC offset going into the integrator. I appreciated that you had split the integrator circuit over the two opamps. One way of improving the performance a bit is to use a two pole high pass filter on the input, instead of the single pole. It gives a much sharper cutoff. I also question whether we really do need a 60 sec response for general purposes? I suspect that 30 to 40 sec would be quite adequate? The other problem with the S/G circuit is that you do need to make an effort to limit the system noise, since the low frequency gains need to be quite high. This is a suitable application for CAZ opamps. I note that to give a velocity signal you need to differentiate the S/G output from 1 to 10 Hz. You would probably be able to use four instead of six stages of 10 Hz LP filter if you did this? A 3.3 mu F capacitor in series with the 50 K Ohm variable input resistor to the HF channel should do this quite well. > Note that it is usually possible to lengthen the period using > digital processing - if there is sufficient signal resolution, as seems > likely with the VM 24 bit ADC. However, doing this to a displacement > signal is likely to give rather large amplitudes at the low frequencies. > Maybe the VM displacement signal could be converted into a velocity signal? Remember that a pendulum with a displacement pickup will act as an accelerometer below the period of the pendulum, so both the SG and the new VM sensor are recording acceleration for teleseismic events. The integrator, in the SG sensor electronics (my LC3 channel), should be producing a velocity signal. I should be able to do the same thing in WinSDR by digitally integrating the acceleration signal from the VM sensor. Great! Can you also differentiate the VM signals above the 1 Hz pendulum frequency to give a velocity signal from 1 to 10 Hz? In the S/G Construction Notes the 'photos of my SG sensors' and the first 'photos of my sensors here' both have broken links. The link to Arie Verveer's S/G seismometers no longer works. Could you put his photos on your website, please? Regards, Chris Chapman
In a message dated 23/04/2006, lcochrane@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     Like the VM channel (LCTST) my LC8 channe= l is=20 pretty much the raw
>     data from the pickup=20 except there are two 60 second high-pass filters in the
> =20    signal path. My LC3 channel, the integrated output, should ha= ve a=20 velocity >response from about 1 second, the period of the pendulum= , to=20 about 50 seconds. I
>     have not made any changes t= o my=20 SG sensor for many years so the
>     value of the=20 integrator parts should be the same.
>
>     T= he=20 circuit at http://psn.quake.net/sg-schm.gif shows a 100 K Ohm
> inp= ut=20 resistor, a 470 K Ohm feedback resistor and a 2 mu F parallel
>=20 capacitor. This RC combination rolls off at a period of only 5.9 seconds=20
> - a factor of 10 less than we want.
>     Do= you=20 still use a 4.7 M Ohm feedback resistor, like in your
> previous=20 circuit at http://psn.quake.net/sgproc.gif ?
>    =20 Moreover, there does not seem to be a 1 sec low pass circuit to
>=20 produce a velocity response?

I still use a 4.7M feedback resistor a= nd a=20 2.2UF cap. There is a 60 second high-pass filter before the integrator to=20 limit the low frequencies and DC offset going into
the=20 integrator.
    I appreciated that you had split the integrator= =20 circuit over the two opamps. One way of improving the performance a bit is t= o=20 use a two pole high pass filter on the input, instead of the single pole. It= =20 gives a much sharper cutoff.
    I also question whether we really do need a 60=20= sec=20 response for general purposes? I suspect that 30 to 40 sec would be quite=20 adequate?
    The other problem with the S/G circuit is that=20= you=20 do need to make an effort to limit the system noise, since the low frequency= =20 gains need to be quite high. This is a suitable application for CAZ=20 opamps.
    I note that to give a velocity signal you need=20= to=20 differentiate the S/G output from 1 to 10 Hz. You would probably be able to=20 use four instead of six stages of 10 Hz LP filter if you did this?= A=20 3.3 mu F capacitor in series with the 50 K Ohm variable input resistor to th= e HF=20 channel should do this quite well.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     Note that it is usually possible to lengt= hen=20 the period using
> digital processing - if there is sufficient sign= al=20 resolution, as seems
> likely with the VM 24 bit ADC. However, doin= g=20 this to a displacement
> signal is likely to give rather large=20 amplitudes at the low frequencies.
> Maybe the VM displacement sign= al=20 could be converted into a velocity signal?

Remember that a pendulum= =20 with a displacement pickup will act as an accelerometer below the period o= f=20 the pendulum, so both the SG and the new VM sensor are recording accelerat= ion=20 for teleseismic events. The integrator, in the SG sensor electronics (my L= C3=20 channel), should be producing a velocity signal. I should be able to do th= e=20 same thing in WinSDR by digitally integrating the acceleration signal from= the=20 VM sensor.
    Great!
    Can you also differentiate the VM signals above= the=20 1 Hz pendulum frequency to give a velocity signal from 1 to 10 Hz?  
 
    In the S/G Construction Notes the 'photos of my= SG=20 sensors' and the first 'photos of my sensors here' both have broken=20 links.
    The link to Arie Verveer's S/G seismometers no=20 longer works. Could you put his photos on your website, please?
 
    Regards,
 
    Chris Chapman
Subject: Re: Glacial outburst flood in Vatnajokull coming from Skaftarkatli From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 24 Apr 2006 13:21:24 +0000 Hi all There where harmonic tremors detected during this glacial flood. Here is a plot of that tremor from the Icelandic Met Office. http://hraun.vedur.is/ja/viku/sidasta/oroahvidur.gif Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: interesting infrasound detections? From: "David Saum" DSaum@............ Date: Mon, 24 Apr 2006 12:50:04 -0400 I am still debugging my infrasound detector, but I have been picking up some interesting detections recently: Here is a 24 hour data plot from this morning http://www.infiltec.com/Infrasound@............... with an interesting data spike at 10:35UT (6:35AM local). Here is a blow up of the data showing that it is actually a small spike followed about 3 seconds later by a larger spike. http://www.infiltec.com/Infrasound@................ And here is a blow up of the two similar detections at 1:30 and 1:35UT (9:30 and 9:35PM local) http://www.infiltec.com/Infrasound@................ I have been picking up 0-10 similar detections per day, generally with the first spike smaller than the second, the spacing is about 3 seconds (all less than 10 seconds) and occasionally there is a third small spike about 3 seconds after the large spike. My infrasound monitor is on my 4th floor deck, with no spatial averaging. I am located in the Washington, DC metro area about 10 miles from Reagan airport and 10 miles from major construction on the Springfield, VA I95 interchange and the Potomac bridge project. Anyone have any idea what these signals could be coming from? System info: Exterior of microbarograph with serial cable: http://www.infiltec.com/Infrasound@................. Interior of microbarograph: http://www.infiltec.com/Infrasound@................. PCB removed from box http://www.infiltec.com/Infrasound@................. PCB and high-pass pneumatic filter removed from box: http://www.infiltec.com/Infrasound@................. System Bandpass: 0.01 to 4 Hz. High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube. Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701) Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D) Pres Resolution: ~0.004 Pa - possibly lower depending offsets Range: +/- 120 Pa (32768 times pressure resolution) Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P) Power: ~2ma 5VDC, derived from PC serial port, no external power supply Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0) Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5) Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000) Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC. Enclosure: diecast aluminum box for shielding (Hammond 1590P) Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767 Wind Spatial Averaging: array of micro-perforated garden tubing Data Log/Display: freeware PC AMASEIS seismic log/analysis software Dave __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: interesting infrasound detections? From: Col Lynam lynam@................ Date: Tue, 25 Apr 2006 09:53:32 +1000 Hi David, are these related to a storm front an the spikes are lightning "up" strike and related "down" strike or thunder? What was the weather like, this day? cheers col lynam Brisbane, Australia David Saum wrote: >I am still debugging my infrasound >detector, but I have been picking up >some interesting detections recently: > >Here is a 24 hour data plot from this morning >http://www.infiltec.com/Infrasound@............... >with an interesting data spike at 10:35UT (6:35AM local). > >Here is a blow up of the data showing that it is >actually a small spike followed about 3 seconds >later by a larger spike. >http://www.infiltec.com/Infrasound@................ > >And here is a blow up of the two similar detections >at 1:30 and 1:35UT (9:30 and 9:35PM local) >http://www.infiltec.com/Infrasound@................ > >I have been picking up 0-10 similar detections per day, >generally with the first spike smaller than the second, >the spacing is about 3 seconds (all less than 10 seconds) >and occasionally there is a third small spike about 3 seconds >after the large spike. > >My infrasound monitor is on my 4th floor deck, with >no spatial averaging. I am located in the Washington, DC >metro area about 10 miles from Reagan airport and 10 >miles from major construction on the Springfield, VA >I95 interchange and the Potomac bridge project. > >Anyone have any idea what these signals could >be coming from? > >System info: > >Exterior of microbarograph with serial cable: >http://www.infiltec.com/Infrasound@................. >Interior of microbarograph: >http://www.infiltec.com/Infrasound@................. >PCB removed from box >http://www.infiltec.com/Infrasound@................. >PCB and high-pass pneumatic filter removed from box: >http://www.infiltec.com/Infrasound@................. > >System Bandpass: 0.01 to 4 Hz. >High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube. >Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701) >Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D) >Pres Resolution: ~0.004 Pa - possibly lower depending offsets >Range: +/- 120 Pa (32768 times pressure resolution) >Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P) >Power: ~2ma 5VDC, derived from PC serial port, no external power supply >Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0) >Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5) >Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000) >Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC. >Enclosure: diecast aluminum box for shielding (Hammond 1590P) >Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767 >Wind Spatial Averaging: array of micro-perforated garden tubing >Data Log/Display: freeware PC AMASEIS seismic log/analysis software > >Dave > >__________________________________________________________ > >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 David,
are these related to a storm front an the spikes are lightning "up" strike and related "down" strike or thunder? What was the weather like, this day?
cheers
col lynam
Brisbane, Australia

David Saum wrote: 
I am still debugging my infrasound
detector, but I have been picking up
some interesting detections recently:

Here is a 24 hour data plot from this morning
http://www.infiltec.com/Infrasound@...............
with an interesting data spike at 10:35UT (6:35AM local).

Here is a blow up of the data showing that it is
actually a small spike followed about 3 seconds
later by a larger spike.
http://www.infiltec.com/Infrasound@................

And here is a blow up of the two similar detections
at 1:30 and 1:35UT (9:30 and 9:35PM local)
http://www.infiltec.com/Infrasound@................

I have been picking up 0-10 similar detections per day,
generally with the first spike smaller than the second,
the spacing is about 3 seconds (all less than 10 seconds)
and occasionally there is a third small spike about 3 seconds
after the large spike.

My infrasound monitor is on my 4th floor deck, with
no spatial averaging.  I am located in the Washington, DC
metro area about 10 miles from Reagan airport and 10
miles from major construction on the Springfield, VA
I95 interchange and the Potomac bridge project.

Anyone have any idea what these signals could
be coming from?

System info:

Exterior of microbarograph with serial cable:
http://www.infiltec.com/Infrasound@.................
Interior of microbarograph:
http://www.infiltec.com/Infrasound@.................
PCB removed from box
http://www.infiltec.com/Infrasound@.................
PCB and high-pass pneumatic filter removed from box:
http://www.infiltec.com/Infrasound@.................

System Bandpass: 0.01 to 4 Hz.
High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube.
Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701)
Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D)
Pres Resolution: ~0.004 Pa - possibly lower depending offsets
Range: +/- 120 Pa (32768 times pressure resolution)
Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P)
Power: ~2ma 5VDC, derived from PC serial port, no external power supply
Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0)
Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5)
Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000)
Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC.
Enclosure: diecast aluminum box for shielding (Hammond 1590P)
Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767
Wind Spatial Averaging: array of micro-perforated garden tubing
Data Log/Display: freeware PC AMASEIS seismic log/analysis software

Dave

__________________________________________________________

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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.
No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.5/322 - Release Date: 22/04/2006 Subject: Re: interesting infrasound detections? From: ChrisAtUpw@....... Date: Mon, 24 Apr 2006 21:57:16 EDT In a message dated 24/04/2006, DSaum@............ writes: I am still debugging my infrasound detector, but I have been picking up some interesting detections recently: Here is a 24 hour data plot from this morning _http://www.infiltec.com/Infrasound@................ (http://www.infiltec.com/Infrasound@................ with an interesting data spike at 10:35UT (6:35AM local). Here is a blow up of the data showing that it is actually a small spike followed about 3 seconds later by a larger spike. _http://www.infiltec.com/Infrasound@................. (http://www.infiltec.com/Infrasound@................. Hi Dave, I suggest that you seal up the air inlet tube and run the apparatus for 24 hrs to see if it is picking up electrical interference - and what sort? I note that you are using the computer power supplies - they are not always well filtered. The signals, although clear, are not very large. Do the times correspond to switching times of the building temperature control or ventilation systems? Maybe switch them on and off to see if you get any peaks? Do you have a fridge, or a water cooler on the same circuit? Could this be power switching on the grid? My lights do flicker occasionally. Regards, Chris Chapman
In a message dated 24/04/2006, DSaum@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am=20 still debugging my infrasound detector, but I have been picking up
some= =20 interesting detections recently:

Here is a 24 hour data plot from t= his=20 morning http://www.inf= iltec.com/Infrasound@...............
with=20 an interesting data spike at 10:35UT (6:35AM local).

Here is a blow= up=20 of the data showing that it is actually a small spike followed about 3 sec= onds=20 later by a larger spike.
http://www.in= filtec.com/Infrasound@................=20
Hi Dave,
 
    I suggest that you seal up the air inlet t= ube=20 and run the apparatus for 24 hrs to see if it is picking up electrical=20 interference - and what sort? I note that you are using the computer power=20 supplies - they are not always well filtered. The signals, although cle= ar,=20 are not very large.
     Do the times correspond to switching time= s of=20 the building temperature control or ventilation systems? Maybe switch t= hem=20 on and off to see if you get any peaks? Do you have a fridge, or a wate= r=20 cooler on the same circuit? Could this be power switching on the grid? My li= ghts=20 do flicker occasionally.
 
    Regards,
 
    Chris Chapman
Subject: Re: interesting infrasound detections? From: "David Saum" DSaum@............ Date: Tue, 25 Apr 2006 07:28:00 -0400 Mystery solved! Unfortunately the source was me. The initial small pulse is my front door opening, and the second larger pulse about 3 seconds later was my front door closing. I was able to reproduce the phenomena at will. Due to warmer weather, a window onto my deck had recently been opened about an inch, and the pulsing of the air from the house due to the front door opening and closing was enough to cause the spikes on my microbarograph. The microbarograph is about 10 feet away from the window, but changing its position does not seem to make much difference in the size of the spikes. My deck is enclosed on all but one side (dim ~20'x10'x10') so all the air in the deck volume seems to be getting pulsed by the window opening. The simplest solution seems to be closing the window, but longer term I need to set up a spatial averaging array of soaker hoses in a field. Sorry for the false alarm. No little green men this time. :( Dave __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: interesting infrasound detections? From: Barry Lotz barry_lotz@............. Date: Tue, 25 Apr 2006 05:39:14 -0700 (PDT) Hi David Maybe it could be some component of the building moving during heating and cooling of the day. Sunny during events? Regard Barry David Saum wrote: I am still debugging my infrasound detector, but I have been picking up some interesting detections recently: Here is a 24 hour data plot from this morning http://www.infiltec.com/Infrasound@............... with an interesting data spike at 10:35UT (6:35AM local). Here is a blow up of the data showing that it is actually a small spike followed about 3 seconds later by a larger spike. http://www.infiltec.com/Infrasound@................ And here is a blow up of the two similar detections at 1:30 and 1:35UT (9:30 and 9:35PM local) http://www.infiltec.com/Infrasound@................ I have been picking up 0-10 similar detections per day, generally with the first spike smaller than the second, the spacing is about 3 seconds (all less than 10 seconds) and occasionally there is a third small spike about 3 seconds after the large spike. My infrasound monitor is on my 4th floor deck, with no spatial averaging. I am located in the Washington, DC metro area about 10 miles from Reagan airport and 10 miles from major construction on the Springfield, VA I95 interchange and the Potomac bridge project. Anyone have any idea what these signals could be coming from? System info: Exterior of microbarograph with serial cable: http://www.infiltec.com/Infrasound@................. Interior of microbarograph: http://www.infiltec.com/Infrasound@................. PCB removed from box http://www.infiltec.com/Infrasound@................. PCB and high-pass pneumatic filter removed from box: http://www.infiltec.com/Infrasound@................. System Bandpass: 0.01 to 4 Hz. High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube. Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701) Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D) Pres Resolution: ~0.004 Pa - possibly lower depending offsets Range: +/- 120 Pa (32768 times pressure resolution) Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P) Power: ~2ma 5VDC, derived from PC serial port, no external power supply Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0) Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5) Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000) Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC. Enclosure: diecast aluminum box for shielding (Hammond 1590P) Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767 Wind Spatial Averaging: array of micro-perforated garden tubing Data Log/Display: freeware PC AMASEIS seismic log/analysis software Dave
Hi David
   Maybe it could be some component of the building moving during heating and cooling of the day. Sunny during events?
Regard
Barry

David Saum <DSaum@............> wrote:
I am still debugging my infrasound
detector, but I have been picking up
some interesting detections recently:

Here is a 24 hour data plot from this morning
http://www.infiltec.com/Infrasound@...............
with an interesting data spike at 10:35UT (6:35AM local).

Here is a blow up of the data showing that it is
actually a small spike followed about 3 seconds
later by a larger spike.
http://www.infiltec.com/Infrasound@................

And here is a blow up of the two similar detections
at 1:30 and 1:35UT (9:30 and 9:35PM local)
http://www.infiltec.com/Infrasound@................

I have been picking up 0-10 similar detections per day,
generally with the first spike smaller than the second,
the spacing is about 3 seconds (all less than 10 seconds)
and occasionally there is a third small spike about 3 seconds
after the large spike.

My infrasound monitor is on my 4th floor deck, with
no spatial averaging. I am located in the Washington, DC
metro area about 10 miles from Reagan airport and 10
miles from major construction on the Springfield, VA
I95 interchange and the Potomac bridge project.

Anyone have any idea what these signals could
be coming from?

System info:

Exterior of microbarograph with serial cable:
http://www.infiltec.com/Infrasound@.................
Interior of microbarograph:
http://www.infiltec.com/Infrasound@.................
PCB removed from box
http://www.infiltec.com/Infrasound@.................
PCB and high-pass pneumatic filter removed from box:
http://www.infiltec.com/Infrasound@.................

System Bandpass: 0.01 to 4 Hz.
High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube.
Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701)
Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D)
Pres Resolution: ~0.004 Pa - possibly lower depending offsets
Range: +/- 120 Pa (32768 times pressure resolution)
Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P)
Power: ~2ma 5VDC, derived from PC serial port, no external power supply
Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0)
Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5)
Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000)
Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC.
Enclosure: diecast aluminum box for shielding (Hammond 1590P)
Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767
Wind Spatial Averaging: array of micro-perforated garden tubing
Data Log/Display: freeware PC AMASEIS seismic log/analysis software

Dave

Subject: Re: Calif--100th Anniversary From: Richard Webb dwebb002@............. Date: Wed, 26 Apr 2006 01:58:08 -0400 John, For Pete's sake please remove our picture. Surely we can come up with a better one. :-) It was great meeting with all of you after having spoken to you on the phone and by email all these years. Nothing better than a great face to face dinner. Thanks, Dick John or Jan Lahr wrote: > I've posted some pictures of the PSN meeting here: > http://jclahr.com/psn/ > > The Seismological Society of America meeting was quite interesting. > For me the highlights were seeing the fence near Crystal Springs > Reservoir that was offset by the 1906 earthquake and seeing the > retrofit of the Oakland City Hall -- it's now resting on huge rubber > pads that provide base isolation. > > Cheers, > John > > At 07:39 PM 4/22/2006, you wrote: >> Thanks Steve, Larry, Richard, John & Jan for arranging the informal >> PSN get-together Tues. eve. We enjoyed several field trips as well >> as several technical sessions during the week. Best wishes in >> keeping the PSN vision alive and well.. Jim > > > __________________________________________________________ > > 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: Haifa Laboratory of earthquake's predictions. From: Alexandr Yagodin midia@.............. Date: Wed, 26 Apr 2006 10:02:47 +0200 Hi to all Colleagues! I inform you, that the work on creation of the project of System of a prediction of earthquakes is executed. Parameters of system unique. The description of System in Russian. If someone can make the qualified translation - I shall be grateful. On this project the positive review from the Chairman of expert council of the Russian Academy of sciences is received. It in Russian. For interested I shall send by electronic mail. The system will be created at the international level and all of you, in due course can become its participants. Best regards to All Alexandr Yagodon Haifa Laboratory of earthquake's predictions. +972-4-8598143 (rus) http://www.seu.ru/members/earthquakes/index.html?x=7139 ----- Original Message ----- From: "Richard Webb" To: Sent: Wednesday, April 26, 2006 7:58 AM Subject: Re: Calif--100th Anniversary > John, > > For Pete's sake please remove our picture. Surely we can come up with a > better one. :-) It was great meeting with all of you > after having spoken to you on the phone and by email all these years. > Nothing better than a great face to face dinner. > > Thanks, > Dick > > > John or Jan Lahr wrote: > > I've posted some pictures of the PSN meeting here: > > http://jclahr.com/psn/ > > > > The Seismological Society of America meeting was quite interesting. > > For me the highlights were seeing the fence near Crystal Springs > > Reservoir that was offset by the 1906 earthquake and seeing the > > retrofit of the Oakland City Hall -- it's now resting on huge rubber > > pads that provide base isolation. > > > > Cheers, > > John > > > > At 07:39 PM 4/22/2006, you wrote: > >> Thanks Steve, Larry, Richard, John & Jan for arranging the informal > >> PSN get-together Tues. eve. We enjoyed several field trips as well > >> as several technical sessions during the week. Best wishes in > >> keeping the PSN vision alive and well.. Jim > > > > > > __________________________________________________________ > > > > 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: Ice quake activite From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 30 Apr 2006 00:40:42 +0000 Hi all Following a rain in south east Iceland, there appears to be ice quake activite following that rain. The ice quakes them selfs are too low qualiti to show up on the Icelandic met office earthquake map. But signal from the can been seen on there tremor plot. Here is the Icelandic met office tremor plots. The ice quake tremors can be seen on three stations near south west corner of Vatnajokull. The ice quakes form a sharp change in the plot. http://hraun.vedur.is/ja/englishweb/tremor.html Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Building a Fmes sensor From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 01 May 2006 08:32:51 +0000 Hi all I am wondering what i need to build fmes sensor. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Large earthquake possiblitie From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 01 May 2006 22:32:41 +0000 Hi all I think that there might be coming a large event (larger then M6.5) somewhere between north cost of Peru and South East coste of the U.S. I base that assumsion of sharp uptrend of earthquakes in the area in past week. This however might be wrong. My time fram is 30 days. This is just a guess and might not come true. Also, at the moment the planet it self seems to be experiensing alot of mid size earthquakes, from size 4.5M to 6.5M, but mostly earthquakes that are around 5M in size. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Large earthquake possiblitie From: "felipe luevanos luevanos" felicaribe5@........... Date: Tue, 02 May 2006 00:04:50 +0000 Hi Jon, I think your prediction has a big chance of success, since the locationn is so large and the frame so long; besides that, it's is a guess. Felipe Luevaos. >From: Jón Frímann >Reply-To: psn-l@.............. >To: PSN-Postlist >Subject: Large earthquake possiblitie >Date: Mon, 01 May 2006 22:32:41 +0000 > >Hi all > >I think that there might be coming a large event (larger then M6.5) >somewhere between north cost of Peru and South East coste of the U.S. I >base that assumsion of sharp uptrend of earthquakes in the area in past >week. This however might be wrong. My time fram is 30 days. This is just >a guess and might not come true. > >Also, at the moment the planet it self seems to be experiensing alot of >mid size earthquakes, from size 4.5M to 6.5M, but mostly earthquakes >that are around 5M in size. > >Regards. >-- >Jón Frímann >http://www.jonfr.com >http://www.simnet.is/jonfr500/earthquake/ > >__________________________________________________________ > >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: Building a Fmes sensor From: Angel sismos@.............. Date: Tue, 2 May 2006 05:00:11 +0000 Hello Jón, I am traveling right now and will not be home for a while. There is no manual and in reality no right or wrong way to build and FMES. I suggest that you join the FMES list and read some of the back emails and look at the photos on the yahoo page. Then I would make a inventory of what parts are available at you local hardware stores and building supply places that sort of look like what is in the photos. Once you have an idea of what is needed to be done and what material you have available we can start. I will be home in the middle of this month then I can help you as much as I can and so will others on the list. It is really not as hard as it looks and there is no wrong way to build and FMES. The yahoo group can be joined at: http://groups.yahoo.com/group/fmes/ We are all learning how to do this and make it better your ideas will help. Regards, Angel Monday, May 1, 2006, 8:32:51 AM, you wrote: > Hi all > I am wondering what i need to build fmes sensor. > Regards. -- Best regards, Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Large earthquake possiblitie From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Tue, 02 May 2006 16:27:00 +0000 Hi Felipe I'm unsure of the success rate. However i find the sharp changes in earthquake activies near Peru and north of it give a clue of what might happen soon. But I don't know for sure as always. I try to use the current data as i can. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large earthquake possiblitie From: ian ian@........... Date: Wed, 03 May 2006 17:37:57 +0100 it may have just happened in Tonga... Ian Jón Frímann wrote: >Hi Felipe > >I'm unsure of the success rate. However i find the sharp changes in >earthquake activies near Peru and north of it give a clue of what might >happen soon. But I don't know for sure as always. I try to use the >current data as i can. > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Are there going to be many earthquakes in May ? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Thu, 04 May 2006 20:33:08 +0000 Hi all The reason for this question in the email title is this. It appears that the planet Jupiter is unusally close to Earth this month. The distance of Jupiter is going to be 659 million kilometers away from Earth. The big question in my mind is this. Becose how close Jupiter is, is it going to have a effects on Earth earthquakes. Since it is already known that the pull from Earth on the moon appears to create earthquakes. Here is the Nasa artical that did spark this observasion of mine. http://science.nasa.gov/headlines/y2006/04may_jupiter.htm?list131101 Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Mt. St. Helens Volcano and its strange rising slab or "fin" shaped material From: "meredith lamb" paleoartifact@......... Date: Sat, 6 May 2006 22:05:37 -0600 Heres a interesting URL with multiple pictures, showing a giant slab or fin shaped material arising out of the edge of the inner crater. Regular news sources claim th= e slab is as big as a football field, and is rising upward at the rate of 4-5 feet a day recently! The crater itself is ~ 2 miles in diameter. http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/framework.html Heres a interesting URL with multiple pictures, showing a giant slab or fin= shaped material
arising out of the edge of the inner crater.  Regular news sources cla= im the slab is as big
as a football field, and is rising upward at the rate of 4-5 feet a day rec= ently!  The crater
itself is ~ 2 miles in diameter.

http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/framework.html


Subject: RE: Mt. St. Helens Volcano and its strange rising slab or "fin" shaped material From: "Kareem" system98765@............. Date: Sun, 7 May 2006 16:21:03 -0700 wow. seems like those days prior to may 18, 1980. (4-5 feet a day). _____ From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Saturday, May 06, 2006 9:06 PM To: psn-l@.............. Subject: Mt. St. Helens Volcano and its strange rising slab or "fin" shaped material Heres a interesting URL with multiple pictures, showing a giant slab or fin shaped material arising out of the edge of the inner crater. Regular news sources claim the slab is as big as a football field, and is rising upward at the rate of 4-5 feet a day recently! The crater itself is ~ 2 miles in diameter. http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/framework.html
wow.
 
seems like those days prior to may 18, 1980. = (4-5 feet a=20 day).

From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of meredith=20 lamb
Sent: Saturday, May 06, 2006 9:06 PM
To:=20 psn-l@..............
Subject: Mt. St. Helens Volcano and its = strange=20 rising slab or "fin" shaped material

Heres a interesting URL with multiple pictures, showing a = giant slab=20 or fin shaped material
arising out of the edge of the inner = crater. =20 Regular news sources claim the slab is as big
as a football field, = and is=20 rising upward at the rate of 4-5 feet a day recently!  The = crater
itself=20 is ~ 2 miles in diameter.

http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/framework.html


Subject: Re: Mt. St. Helens Volcano and its strange rising slab or "fin" From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 07 May 2006 23:43:51 +0000 Hi all This slab that is coming out of Mt. St. Helens volcano crater is really intresting. It looks like it is coming from deep underground. If it survies the formation of a new lava dome it is going to give huge amount of info about inner structure of Mt. St. Helens. This slab might also be really, really old if it is coming from deep underground. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mt. St. Helens Volcano and its strange rising slab or "fin"shaped material From: "Geoffrey" gmvoeth@........... Date: Sun, 7 May 2006 22:53:13 -0700 You guys never saw that movie "Monolith Monsters" ----- Original Message ----- From: "Jón Frímann" To: Sent: Sunday, May 07, 2006 4:43 PM Subject: Re: Mt. St. Helens Volcano and its strange rising slab or "fin"shaped material > Hi all > > This slab that is coming out of Mt. St. Helens volcano crater is really > intresting. It looks like it is coming from deep underground. If it > survies the formation of a new lava dome it is going to give huge amount > of info about inner structure of Mt. St. Helens. This slab might also be > really, really old if it is coming from deep underground. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > 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: eBay seismometer listing From: Bobhelenmcclure@....... Date: Mon, 8 May 2006 22:29:03 EDT Seismometer GeoSpace Geo-Space Seismology Earthquake Item number: 7617763900 Model HS-????/3D Apparently a 3 axis sensor, maybe of HS-10 type? Bob
Seismometer GeoSpace Geo-Space Seismology Earthquake
Item number: 7617763900
Model HS-????/3D
 
  Apparently a 3 axis sensor, maybe of HS-10 type?
 
Bob
 Subject: Use of Cat-5 cable when connecting a geophone From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 10 May 2006 04:07:09 +0000 Hi all I use cat-5 network cable to connect my geophone to my winsdr amplifer board. So far my experience with that type of cable has been good. Since it appears not to pickup alot of noise from it's closest evroment. Also the signal loss seems to be minimal, even if the cable is some meters in lengh. I don't know if anyone else is using cat-5. But comment on this usage of cat-5 are what i need to know if this is a good thing or not. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Use of Cat-5 cable when connecting a geophone From: Jim E ODonell jimo17@........ Date: Tue, 9 May 2006 21:37:08 -0700 Hi Jon- I have used it for years in Down Hole (3 geophones down the hole) seismic surveys- Since it has twisted pairs this reduces the noise pickup and it is cheap. It is #24 solid wire which breaks real easy if it gets moved a lot. But once in place it should do fine....Jim Jim O'Donnell Geological/Geophysical Consultant GEOTECHNICAL APPLICATIONS On Wed, 10 May 2006 04:07:09 +0000 =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= writes: > Hi all > > I use cat-5 network cable to connect my geophone to my winsdr > amplifer > board. So far my experience with that type of cable has been good. > Since > it appears not to pickup alot of noise from it's closest evroment. > Also > the signal loss seems to be minimal, even if the cable is some > meters in > lengh. > > I don't know if anyone else is using cat-5. But comment on this > usage of > cat-5 are what i need to know if this is a good thing or not. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > 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 Jon-
I have used it for years in Down Hole (3 geophones down the hole) = seismic=20 surveys-  Since it has twisted pairs this reduces the noise pickup and= it=20 is cheap.  It is #24 solid wire which breaks real easy if it gets = moved a=20 lot.   But once in place it should do fine....Jim
 
                Jim O'Donnell    =20
         Geological/Geophysical Consultant
            GEOTECHNICAL APPLICATIONS
On Wed, 10 May 2006 04:07:09 +0000 =3D?ISO-8859-1?Q?J=3DF3n_Fr=3D= EDmann?=3D <jonfr500@.........> writes:
&= gt; Hi=20 all
>
> I use cat-5 network cable to connect my geophone to my= =20 winsdr
> amplifer
> board. So far my experience with that type= of=20 cable has been good.
> Since
> it appears not to pickup alot = of=20 noise from it's closest evroment.
> Also
> the signal loss = seems to=20 be minimal, even if the cable is some
> meters in
> lengh.
= >=20
> I don't know if anyone else is using cat-5. But comment on this=20
> usage of
> cat-5 are what i need to know if this is a good = thing=20 or not.
>
> Regards.
> --
> J=F3n Fr=EDmann
&= gt; http://www.jonfr.com
> http://www.simnet.is/= jonfr500/earthquake/
>=20
> __________________________________________________________
>= =20
> Public Seismic Network Mailing List (PSN-L)
>
> To = leave=20 this list email PSN-L-REQUEST@.............. with=20
> the body of the message (first line only): unsubscribe
> See= http://www.seismicnet.com/= maillist.html=20 for more information.
>
>
 
Subject: Seismic clipping levels From: Brett Nordgren Brett3kg@............. Date: Mon, 15 May 2006 10:15:51 -0400 To all, There is a relatively new USGS report that gives the maximum expected ground motion at 87 continental US locations (the UNSS backbone stations) for the purpose of testing instrument clipping levels. Clipping levels and max ground motion is a subject that fairly regularly comes up on PSN-L and this data may help provide some good guidance. The report can be downloaded from http://pubs.usgs.gov/of/2005/1437/ To come up with the data the authors had to do some extremely complex statistical work which I am currently trying to understand, but it's clear that coming up with good data isn't easy. Their numbers give the ground motion levels that had a 10% chance of being exceeded in a time period of 30 years. That's probably way too conservative for amateur work; better would probably be 10% in 1 year or even 50% in 1 year. I'm trying to understand their process well enough to be able to manipulate the raw data to get those, but I still have a lot to learn. I've put the results in an Excel file http://bnordgren.org/seismo/station_pgv.xls (164kb) in a form that includes spectrum charts, which should be useful to compare with individual instrument clipping levels. And the general process should be useful in evaluating sites anywhere in the world. If anyone who really understands this stuff can point me to resources relating to the statistical methods and raw data sources, I would be most grateful. Regards, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: neis web page??? From: "Connie and Jim Lehman" lehmancj@........... Date: Mon, 15 May 2006 20:36:16 -0400 PSN folks--for months/years I have had the National Earthquake = Information Service Web site bookmarked in for easy access to current = seismic events. In the past week or so a strange NEIS page comes up = with no information. Has there been an address change?? I would think = the service would continue with excellent public information as it has = in the past. Any ideas?? Jim Lehman =20
PSN folks--for months/years I have had = the National=20 Earthquake Information Service Web site bookmarked in for easy access to = current=20 seismic events.  In the past week or so a strange NEIS page = comes up=20 with no information.  Has there been an address change??  I = would=20 think the service would continue with excellent public information as it = has in=20 the past.   Any = ideas??        Jim=20 Lehman 
Subject: Re: neis web page??? From: apsn apsn@........... Date: Mon, 15 May 2006 17:39:07 -0800 http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/quakes_all.php NEIS changed their look and links. Bob Hammond http://apsn.awcable.com At 01:37 PM 5/15/2006, you wrote: >PSN folks--for months/years I have had the National Earthquake >Information Service Web site bookmarked in for easy access to >current seismic events. In the past week or so a strange NEIS page >comes up with no information. Has there been an address change?? I >would think the service would continue with excellent public >information as it has in the past. Any ideas?? Jim Lehman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: My Kermadec Islands Region earthquake recording From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Tue, 16 May 2006 13:23:23 +0000 Hi all I did record the Kermadec Islands Region earthquake, I did detect the seismic waves, but there are many strange things in this recording. I can't explain them, yet anyway. I did check with the Icelandic met Office, there was no earthquake near Iceland or in Iceland at the same time as the Kermadec Islands earthquake that might explain the signals. The signals can be seen on the psn event file list. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: neis web page??? From: "Geoffrey" gmvoeth@........... Date: Tue, 16 May 2006 15:29:07 -0700 http://earthquake.usgs.gov/ Thats the one I use and it has been good for a very long time. ----- Original Message ----- From: "Connie and Jim Lehman" To: Sent: Monday, May 15, 2006 5:36 PM Subject: neis web page??? PSN folks--for months/years I have had the National Earthquake Information Service Web site bookmarked in for easy access to current seismic events. In the past week or so a strange NEIS page comes up with no information. Has there been an address change?? I would think the service would continue with excellent public information as it has in the past. Any ideas?? Jim Lehman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: My Kermadec Islands Region earthquake recording From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Tue, 16 May 2006 23:24:49 +0000 Hi all Sorry for the repost, but i problay was not clear enugh on the strangeness in the Kermadec Islands. But here is the problem. The earthquake wave that i did record does not fit predicted p and s arrival time. I find it to be really strange, I can't explain this. I was hopeing that somebody on the psn mail list might. The trance is here. http://seismicnet.com/cgi-dos/event.exe The station name is Hvammstangi. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fw: neis web page??? From: "Thomas Dick" dickthomas01@............. Date: Tue, 16 May 2006 18:45:37 -0500 > http://earthquake.usgs.gov/ > >The site started to change sometime before March. I believe they got a new >website manager. At that time they dropped P arrival times for anything >under 4 mag and the site became slower when using MSN Explorer. I switched >to Firefox and things got better. Then the moved the site and the redirect >seems to slow it down or it now nonexistant. You might try updating your >bookmarks. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My Kermadec Islands Region earthquake recording From: ChrisAtUpw@....... Date: Tue, 16 May 2006 20:32:45 EDT In a message dated 17/05/06, jonfr500@......... writes: > The earthquake wave that i did record does not fit predicted p and s arrival > time. Hi Jon, Download the time / travel chart! You are 160 deg long and 100 deg lat away and you are using geophones. Regards, Chris Chapman In a message=20= dated 17/05/06, jonfr500@......... writes:

The earthquake wave that i=20= did record does not fit predicted p and s arrival
time.
Hi Jon,

      Download the time / travel chart! Y= ou are 160 deg long and 100 deg lat away and you are using geophones.

      Regards,

      Chris Chapman
Subject: Re: My Kermadec Islands Region earthquake recording From: Mark Robinson mark.robinson@............... Date: Wed, 17 May 2006 12:45:59 +1200 Jón Frímann wrote: > Hi all > > Sorry for the repost, but I probably was not clear enough on the > strangeness in the Kermadec Islands. But here is the problem. The > earthquake wave that I did record does not fit predicted P and S arrival > time. I find it to be really strange, I can't explain this. I was > hoping that somebody on the PSN mail list might. The trace is here. The time on the computer you used to send the email appears to be about 27 seconds fast but that is not enough of an error to explain the displacement. The arrivals on USGS sensors in your area seem to be roughly in line with the predicted P and S times on your traces. Is the time on your recording computer correct ? > http://seismicnet.com/cgi-dos/event.exe That URL gives me The Fear. I tell every windows user to never click on anything ending on .exe. > The station name is Hvammstangi. There is a place a little way up the road called Himitangi. This event was well felt in Wellington New Zealand about 1500km from the epicentre. Water (and other liquids) sloshed about in glasses and we experienced several minutes of gentle rolling and log period shudder: http://zl2tod.net/~mark/200605161250gmt-geonet-drums.html There were a number of interesting frequency ramp signals on the proximate USGS Rarotonga sensor in the 24 hours leading up to the event: http://zl2tod.net/~mark/200605161250gmt-RAR_24hr.html And considerable background activity at various frequencies on the USGS Raoul Island Kermadec sensor: http://zl2tod.net/~mark/200605161250gmt-RAO_24hr.html This is not unusual for this location. These sensors and a number of others seem to have gone offline an hour or so after the event. Coincidentally this event comes almost exactly one year after some eigenmode activity around the planet: http://zl2tod.net/~mark/200505151251-liss-eigenmode-heli2.shtml which was followed by this event in the Kermadecs: http://zl2tod.net/~mark/20050516-kermadecs-and%20eigenmode-SNZO_24hr.gif Any comments from the learned appreciated. Cheers Mark __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My Kermadec Islands Region earthquake recording From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 17 May 2006 00:48:28 +0000 Hi Chris According to this map, http://neic.usgs.gov/neis/eq_depot/2006/eq_060516_muah/neic_muah_t.html I am in the p shadow zone. This earthquake was also picked up by the IMO earthquake sensors across Iceland. The IMO tremor plot is here, it creates a large spike when the earthquake is detected, http://hraun.vedur.is/ja/englishweb/tremor.html But what surprices me the most is the fact i did actually detect this earthquake, at this range. Even if the p and s waves are strange. I didn't think this was possible with my geophone. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My Kermadec Islands Region earthquake recording From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 17 May 2006 01:04:15 +0000 Hi Mark The computer i use to send email is not the same computer i use to keep recording from the geophone. That computer is time regluated by ntp every 15 min. The time source is going to be moved to a gps clock when it arrives. I have corrected the time on my computer with ntp, but I use ntp to regulate the time on my computer. I don't know why Larry uses *.exe in the end of the cgi-dos setup. But it is save. > There is a place a little way up the road called Himitangi. I don't understand. Please explain. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: thanks for NEIS info. From: "Connie and Jim Lehman" lehmancj@........... Date: Tue, 16 May 2006 20:40:20 -0400 Many thanks to John, Bob, Thomas & Geoffrey for bringing me up to date = on the changes in the NEIS page. I am bookmarked ok again. I remember the not so old days when we waited for the bi-weekly or = monthly bulletins to arrive by mail ...or at times place a long distance = call to the Colorado Center and talk directly to Waverly Persons or one = of his associates---they were always patient and helpful. = Jim Lehman
Many thanks to John, Bob, Thomas & = Geoffrey for=20 bringing me up to date on the changes in the NEIS page.  I am = bookmarked ok=20 again.
  I remember the not so old days = when we=20 waited for the bi-weekly or monthly bulletins to arrive by mail ...or at = times=20 place a long distance call to the Colorado Center and talk directly to = Waverly=20 Persons or one of his associates---they were always patient and=20 helpful.           = ;   =20 Jim Lehman
Subject: hammer seismic interpretation From: james fisher kd6iwd@......... Date: Tue, 16 May 2006 18:37:54 -0700 (PDT) Hi, I have a question about interpretation of seismic data for the group. I have built a hammer seismic system which incorporates a memory scope. I can hammer the ground any number of times and sum the returned signal. This gives vastly increased sensitivity and immunity to noise. can anyone suggest sources of information on how to measure the depth to bedrock with this type of device? I have used the sound card on a pc and piezo disks to detect and trigger the data collection. Best Regards jim __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: hammer seismic interpretation From: ChrisAtUpw@....... Date: Tue, 16 May 2006 23:19:15 EDT In a message dated 17/05/06, kd6iwd@......... writes: > I have built a hammer seismic system which incorporates a memory scope. I > can hammer the ground any number of times and sum the returned signal. This > gives vastly increased sensitivity and immunity to noise. Can anyone suggest > sources of information on how to measure the depth to bedrock with this type > of device? Hi Jim, Can you use two high frequency piezo disks with a light centre load and a summing amplifier? You may have to damp the disks with polyurethane foam. Put one disk close to the hammer plate and the other several feet away. The timing in between the two disks will ~measure the ground velocity and then you look for reflections. But you need to reckon on 3 to 5 km / sec for the ground waves - you are likely to be measuring time intervals in milliseconds, if not microseconds. I think that commercial type equipment will probably use a variable gain amplifier (transconductance type) triggered by the initial pulse. The reflected signal drops off at about the 4th power of the depth. By separating the two sensors, you can put a higher gain on the remote one. This might be an application for silicon accelerometers? They may have a higher natural frequency than piezo disks. Do you have any estimate of the depth to the bedrock? Regards, Chris Chapman In a message=20= dated 17/05/06, kd6iwd@......... writes:

I have built a hammer seism= ic system which incorporates a memory scope. I
can hammer the ground any number of times and sum the returned signal. T= his gives vastly increased sensitivity and immunity to noise. Can anyone sug= gest
sources of information on how to measure the depth to bedrock with this=20= type of device?
Hi Jim,

      Can you use two high frequency piez= o disks with a light centre load and a summing amplifier? You may have to da= mp the disks with polyurethane foam. Put one disk close to the hammer plate=20= and the other several feet away. The timing in between the two disks will ~m= easure the ground velocity and then you look for reflections. But you need t= o reckon on 3 to 5 km / sec for the ground waves - you are likely to be meas= uring time intervals in milliseconds, if not microseconds. I think that comm= ercial type equipment will probably use a variable gain amplifier (transcond= uctance type) triggered by the initial pulse. The reflected signal drops off= at about the 4th power of the depth. By separating the two sensors, you can= put a higher gain on the remote one.=20
      This might be an application for si= licon accelerometers? They may have a higher natural frequency than piezo di= sks. Do you have any estimate of the depth to the bedrock?

      Regards,

      Chris Chapman Subject: Re: My Kermadec Islands Region earthquake recording From: ChrisAtUpw@....... Date: Tue, 16 May 2006 23:26:19 EDT In a message dated 17/05/06, jonfr500@......... writes: > But what surprices me the most is the fact i did actually detect this > earthquake, at this range. Even if the p and s waves are strange. I > didn't think this was possible with my geophone. Hi Jon, With large quakes you can also pick up locally generated noise. The geophone response falls off below 4.5 Hz as f^2 - it does not go to zero. Do a FFT and see what the signal peak frequencies were? Regards, Chris Chapman In a message=20= dated 17/05/06, jonfr500@......... writes:

But what surprices me the m= ost is the fact i did actually detect this
earthquake, at this range. Even if the p and s waves are strange. I
didn't think this was possible with my geophone.
Hi Jon,

      With large quakes you can also pick= up locally generated noise. The geophone response falls off below 4.5 Hz as= f^2 - it does not go to zero. Do a FFT and see what the signal peak frequen= cies were?

      Regards,

      Chris Chapman Subject: Re: My Kermadec Islands Region earthquake recording From: Larry Cochrane lcochrane@.............. Date: Tue, 16 May 2006 20:44:30 -0700 The link http://www.seismicnet.com/cgi-dos/event.exe is save to use. This runs a program / cgi script on MY web server to send back a list of recent events to the user's web browser. The exe file does not run on the users system. Regards, Larry Cochrane Redwood City, PSN Jón Frímann wrote: > I don't know why Larry uses *.exe in the end of the cgi-dos setup. But > it is save. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My Kermadec Islands Region earthquake recording From: Larry Cochrane lcochrane@.............. Date: Tue, 16 May 2006 20:58:45 -0700 Hi Jón, Besides your timing make sure your latitude and longitude are correct. This information is also used by WinQuake to calculate the correct P and S locations. I see from your event files that you have your latitude set to 65.4N. Is it really 65.400N? Once you get your GPS receiver you can use it to get your sensors location to 5 or 6 decimal places. You will need to let WinSDR average the data from the receiver for a few days to get this type of accuracy. Regards, Larry Cochrane Redwood City, PSN Jón Frímann wrote: > Hi Mark > > The computer i use to send email is not the same computer i use to keep > recording from the geophone. That computer is time regluated by ntp > every 15 min. The time source is going to be moved to a gps clock when > it arrives. I have corrected the time on my computer with ntp, but I use > ntp to regulate the time on my computer. > > I don't know why Larry uses *.exe in the end of the cgi-dos setup. But > it is save. > >> There is a place a little way up the road called Himitangi. > > I don't understand. Please explain. > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My Kermadec Islands Region earthquake recording From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 17 May 2006 07:10:05 +0000 Hi Larry I did use 65.400N but winsdr did shorten it down to 65.4N, but it looks correct on the map. I have actually incresed the accurancy, since I have updated my location with gps data I got from a gps handlet device I own. That gives me 5 or 6 decimal places, but I did just use three numbers in the location. I problay can use four to five numbers when the gps receiver is used. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My Kermadec Islands Region earthquake recording From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 17 May 2006 07:15:10 +0000 Hi Chris I did clean everything above 1Hz out of the recording to actually see the signal. I did the same thing with the eastern siberia earthquake in April, that i did detect. Even if the response fall flat below 2Hz, there seems to be surpriceing alot of data below 2Hz. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: My Kermadec Islands Region earthquake recording From: ChrisAtUpw@....... Date: Wed, 17 May 2006 05:53:52 EDT In a message dated 17/05/06, jonfr500@......... writes: > did clean everything above 1Hz out of the recording to actually see > the signal. I did the same thing with the eastern siberia earthquake in > April, that I detected. Even if the response falls flat below 2Hz, > there seems to be surprising lot of data below 2Hz. Hi Jon, The geophone response will fall to 1/5 at 2Hz, to 1/20 at 1 Hz and to 1/100 at 0.45 Hz. It does not 'fall flat', more like it takes a 'nose dive'! If you get strong enough seismic signals you will certainly see them to below 1 Hz. You may also see locally generated noise as the result of the quake. The geophone compensator circuits are designed to go from the 20 / 10 Hz of the low pass filter down to 0.45 Hz, flat to velocity. You do get some additional noise, but it is quite small. This does enable you to detect teleseismic P and S waves with a 4.5 Hz geophone. Regards, Chris Chapman In a message=20= dated 17/05/06, jonfr500@......... writes:

I
did clean everything abov= e 1Hz out of the recording to actually see
the signal. I did the same thing with the eastern siberia earthquake in
April, that I detected. Even if the response falls flat below 2Hz,
there seems to be surprising lot of data below 2Hz.
Hi Jon,

      The geophone response will fall to=20= 1/5 at 2Hz, to 1/20 at 1 Hz and to 1/100 at 0.45 Hz. It does not 'fall flat'= , more like it takes a 'nose dive'!
      If you get strong enough seismic si= gnals you will certainly see them to below 1 Hz. You may also see locally ge= nerated noise as the result of the quake.
      The geophone compensator circuits a= re designed to go from the 20 / 10 Hz of the low pass filter down to 0.45 Hz= , flat to velocity. You do get some additional noise, but it is quite small.= This does enable you to detect teleseismic P and S waves with a 4.5 Hz geop= hone.

      Regards,

      Chris Chapman
Subject: Re: My Kermadec Islands Region earthquake recording From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 17 May 2006 12:20:28 +0000 Hi Chris Ok, I was just looking at the plot that is about the geophone i own. The wave I did record must have been some type of reflection in the earth mantle or from it's core, that might explain the signal I got and the signal that was detected by IMO at the same time. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: hammer seismic interpretation From: apsn apsn@........... Date: Wed, 17 May 2006 09:22:47 -0800 Jim, Here's a few links which might help you: http://www.geometrics.com/sci.html ftp://geom.geometrics.com/pub/seismic/Literature/s-tr2.pdf http://www.cflhd.gov/agm/geoApplications/SurfaceMethods/92SeismicMethods.htm http://www.epa.gov/OUST/pubs/esa-ch3.pdf and this publication: Dobecki, T.L. and P.R. Romig. 1985. Geotechnical and groundwater geophysics. In Geophys., vol. 50, no. 12: 2621-36. Cool setup, Jim! Bob http://apsn.awcable.com At 04:49 PM 5/16/2006, you wrote: >Hi, I have a question about interpretation of >seismic data for the group. I have built a hammer >seismic system which incorporates a memory scope. I >can hammer the ground any number of times and sum the >returned signal. This gives vastly increased >sensitivity and immunity to noise. can anyone suggest >sources of information on how to measure the depth to >bedrock with this type of device? > >I have used the sound card on a pc and piezo disks to >detect and trigger the data collection. > >Best Regards > >jim >__________________________________________________________ > >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: WSDR utc setting From: "Francesco" fra.nuc@........... Date: Sat, 20 May 2006 08:19:50 +0200 Hi all. I must use my pc, where WS runs (sdr-winsdr system), under Utc time for another weather software. If I set pc clock in standard GMT, WinSDR shows only Utc time information and not local time too and it's unable to lock with Gps. After some minutes WS crash... I'm sure that it' a mistake of mine, but I am not able to solve the problem Help me... Thank's everybody Francesco Italy __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Test Message From: Larry Cochrane lc2@.............. Date: Fri, 19 May 2006 23:37:03 -0700 Sorry everyone I need to run a test. Please do not respond to this message... Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WSDR utc setting From: Tamati chief.cook.nz@............ Date: Sat, 20 May 2006 23:54:34 +1200 TAMATI's WORD's OF WISDOM FOR THE GOOD OF ALL MANKIND HTTP://LIVE-PLANET.BLOGSPOT.COM http://www.webspawner.com/users/chiefcooknz/index.html Please give me feed back on what you think chief.cook.nz.@............ NZ-021-150-33-59 or NZ-07-855-0195 Hi Francesco from NZ You may by able to sort it out in the "INTERNET TIME" I use Windows XP and there are three option in mine the other way is to do two things get a time convertion from the world Clock website and manually reset your clock and download a small prg called ATOMIC CLOCK the reset you clock to your country I thing it gets time with in a nanno second other than that you can get a script reader (friend) to read a script so that when you load your prg it restart you clock (Emulator) Cheers Tamati From the Castle of Tamati, Hinemoa and Karauwa the Dog From the Castle of Tom, Robyn and the Dog I'm Just a Stone's Throw Away:- NZ-021-150-33-59 or NZ-07-855-0195 Bush Telegragh:- chief.cook.nz@............ My Regular Pitstop:- Tamati P.O.BOX 19-356 CENTRAL HAMILTON NEW ZEALAND ----- Original Message ----- From: "Francesco" To: Sent: Saturday, May 20, 2006 6:19 PM Subject: WSDR utc setting > Hi all. > I must use my pc, where WS runs (sdr-winsdr system), under Utc time for > another weather software. > If I set pc clock in standard GMT, WinSDR shows only Utc time information > and not local time too and it's unable to lock with Gps. After some > minutes WS crash... > I'm sure that it' a mistake of mine, but I am not able to solve the > problem > Help me... > Thank's everybody > > Francesco Italy > > __________________________________________________________ > > 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: WSDR utc setting From: "Geoffrey" gmvoeth@........... Date: Sat, 20 May 2006 06:25:02 -0700 Due to delays in electronic circuitry and propagation delays the best you can do is probably milliseconds behind real time. Nano Seconds or femto seconds or atto seconds is kinda hard to believe unless you have am Atomic Clock of your very own. Lets Say you have such a thing how in the world do you exactly synchronize two clocks, one which has been moved to a new location ??? ----- Original Message ----- From: "Tamati" To: Sent: Saturday, May 20, 2006 4:54 AM Subject: Re: WSDR utc setting > TAMATI's WORD's OF WISDOM > FOR THE GOOD OF ALL MANKIND > HTTP://LIVE-PLANET.BLOGSPOT.COM > http://www.webspawner.com/users/chiefcooknz/index.html > Please give me feed back on what you think > chief.cook.nz.@............ > NZ-021-150-33-59 or NZ-07-855-0195 > > Hi Francesco from NZ > > You may by able to sort it out in the "INTERNET TIME" I use Windows XP and > there are three option in mine the other way is to do two things get a time > convertion from the world Clock website and manually reset your clock > > and download a small prg called ATOMIC CLOCK the reset you clock to your > country I thing it gets time with in a nanno second > > other than that you can get a script reader (friend) to read a script so > that when you load your prg it restart you clock (Emulator) > > Cheers Tamati > From the Castle of Tamati, Hinemoa and Karauwa the Dog > From the Castle of Tom, Robyn and the Dog > > I'm Just a Stone's Throw Away:- NZ-021-150-33-59 or NZ-07-855-0195 > Bush Telegragh:- chief.cook.nz@............ > My Regular Pitstop:- Tamati > P.O.BOX > 19-356 CENTRAL > HAMILTON > NEW > ZEALAND > ----- Original Message ----- > From: "Francesco" > To: > Sent: Saturday, May 20, 2006 6:19 PM > Subject: WSDR utc setting > > >> Hi all. >> I must use my pc, where WS runs (sdr-winsdr system), under Utc time for >> another weather software. >> If I set pc clock in standard GMT, WinSDR shows only Utc time information >> and not local time too and it's unable to lock with Gps. After some >> minutes WS crash... >> I'm sure that it' a mistake of mine, but I am not able to solve the >> problem >> Help me... >> Thank's everybody >> >> Francesco Italy >> >> __________________________________________________________ >> >> 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: WSDR utc setting From: Tamati chief.cook.nz@............ Date: Sun, 21 May 2006 06:12:03 +1200 TAMATI's WORD's OF WISDOM FOR THE GOOD OF ALL MANKIND HTTP://LIVE-PLANET.BLOGSPOT.COM http://www.webspawner.com/users/chiefcooknz/index.html Please give me feed back on what you think chief.cook.nz.@............ NZ-021-150-33-59 or NZ-07-855-0195 do a google search "ATOMIC CLOCK" and check it out your self I'm in the process of changing HDD's and the prg and link which the link is inside the prg I can't give to you as the prg is on the disconnected HDD Cheers Tamati From the Castle of Tamati, Hinemoa and Karauwa the Dog From the Castle of Tom, Robyn and the Dog I'm Just a Stone's Throw Away:- NZ-021-150-33-59 or NZ-07-855-0195 Bush Telegragh:- chief.cook.nz@............ My Regular Pitstop:- Tamati P.O.BOX 19-356 CENTRAL HAMILTON NEW ZEALAND ----- Original Message ----- From: "Geoffrey" To: Sent: Sunday, May 21, 2006 1:25 AM Subject: Re: WSDR utc setting > Due to delays in electronic circuitry > and propagation delays the best you can do > is probably milliseconds behind real time. > > Nano Seconds or femto seconds or atto seconds > is kinda hard to believe unless you have > am Atomic Clock of your very own. > > Lets Say you have such a thing how in > the world do you exactly synchronize > two clocks, one which has been moved > to a new location ??? > > ----- Original Message ----- > From: "Tamati" > To: > Sent: Saturday, May 20, 2006 4:54 AM > Subject: Re: WSDR utc setting > > >> TAMATI's WORD's OF WISDOM >> FOR THE GOOD OF ALL MANKIND >> HTTP://LIVE-PLANET.BLOGSPOT.COM >> http://www.webspawner.com/users/chiefcooknz/index.html >> Please give me feed back on what you think >> chief.cook.nz.@............ >> NZ-021-150-33-59 or NZ-07-855-0195 >> >> Hi Francesco from NZ >> >> You may by able to sort it out in the "INTERNET TIME" I use Windows XP >> and there are three option in mine the other way is to do two things get >> a time convertion from the world Clock website and manually reset your >> clock >> >> and download a small prg called ATOMIC CLOCK the reset you clock to your >> country I thing it gets time with in a nanno second >> >> other than that you can get a script reader (friend) to read a script so >> that when you load your prg it restart you clock (Emulator) >> >> Cheers Tamati >> From the Castle of Tamati, Hinemoa and Karauwa the Dog >> From the Castle of Tom, Robyn and the Dog >> >> I'm Just a Stone's Throw Away:- NZ-021-150-33-59 or NZ-07-855-0195 >> Bush Telegragh:- chief.cook.nz@............ >> My Regular Pitstop:- Tamati >> P.O.BOX >> 19-356 CENTRAL >> HAMILTON >> NEW >> ZEALAND >> ----- Original Message ----- >> From: "Francesco" >> To: >> Sent: Saturday, May 20, 2006 6:19 PM >> Subject: WSDR utc setting >> >> >>> Hi all. >>> I must use my pc, where WS runs (sdr-winsdr system), under Utc time for >>> another weather software. >>> If I set pc clock in standard GMT, WinSDR shows only Utc time >>> information and not local time too and it's unable to lock with Gps. >>> After some minutes WS crash... >>> I'm sure that it' a mistake of mine, but I am not able to solve the >>> problem >>> Help me... >>> Thank's everybody >>> >>> Francesco Italy >>> >>> __________________________________________________________ >>> >>> 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) > > 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: WSDR utc setting From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 21 May 2006 02:38:08 +0000 Hi WinSdr extract time data from GPS and problay local time from the computer. When both are set to UTC WinSDR shoud not crash. The time source has to be set to GPS. I am getting GPS antenna soon, but I am on UTC time, I can tell you if I see the same issue that you are having. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Earthquake sonar software From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 21 May 2006 16:10:17 +0000 Hi all Is there a software out there that can draw a picture of what earthquake wave passes trugh ? Something like a sonar type of software. I am not sure of the this is excaly called in english. I will try to clear this up if this can't be understand in this email. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake sonar software From: apsn apsn@........... Date: Sun, 21 May 2006 08:56:50 -0800 Jon, Give this program a try, it is great! http://www.geol.binghamton.edu/faculty/jones/#Seismic%20Waves Regards, Bob Hammond Public Seismic Network - Alaska http://apsn.awcable.com At 12:21 AM 5/21/2006, you wrote: >Hi all > >Is there a software out there that can draw a picture of what earthquake >wave passes trugh ? Something like a sonar type of software. I am not >sure of the this is excaly called in english. I will try to clear this >up if this can't be understand in this email. > >Regards. >-- >J=F3n Fr=EDmann >http://www.jonfr.com >http://www.simnet.is/jonfr500/earthquake/ > >__________________________________________________________ > >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 sonar software From: ChrisAtUpw@....... Date: Sun, 21 May 2006 13:15:11 EDT In a message dated 21/05/2006, jonfr500@......... writes: Is there a software out there that can draw a picture of what earthquake wave passes through? Something like a sonar type of software. I am not sure of the this is exactly called in english. I will try to clear this up if this can't be understand in this email. Hi Jon, There are world wide seismic demonstration programs showing how quake signals propagate and interact at _http://web.ics.purdue.edu/~braile/edumod/svintro/svintro.htm_ (http://web.ics.purdue.edu/~braile/edumod/svintro/svintro.htm) For local earthquakes, reflection / refraction signals and seismic prospecting you may need arrays of sensors and quite elaborate data analysis programs. Regards, Chris Chapman
In a message dated 21/05/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Is there=20 a software out there that can draw a picture of what earthquake
wave pa= sses=20 through? Something like a sonar type of software. I am not
sure of the=20= this=20 is exactly called in english. I will try to clear this
up if this can't= be=20 understand in this email.
Hi Jon,
 
    There are world wide seismic demonstration prog= rams=20 showing how quake signals propagate and interact at http:/= /web.ics.purdue.edu/~braile/edumod/svintro/svintro.htm
    For local earthquakes, reflection / refraction=20 signals and seismic prospecting you may need arrays of sensors and= =20 quite elaborate data analysis programs.
 
    Regards,
 
    Chris Chapman
 Subject: Giant slab near earth core found From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 21 May 2006 18:09:36 +0000 Hi all I found this intresting news, but scientists have found giant slab that they think was once ocen floor, near the earth core. More about this here, http://www.livescience.com/forcesofnature/060517_inside_earth.html Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake sonar software From: "Geoffrey" gmvoeth@........... Date: Sun, 21 May 2006 17:35:20 -0700 I used to work in SONAR and have since come to realize the Physics of SONAR has come from the geophysicist more then anywhere else. The military wants to keep all this SONAR stuff Secret but all you need to do is study geophysics and transfer what you learn there to SONAR to understand the possibilities. In water it is simpler because no S waves to worry about. Just look at the P waves for SONAR. Water has all kinds of velocity boundaries for reflection and refraction just like layers in the EARTH. You can hear things like diesel engines 2000 miles away because of how those "P" waves move. I cant help but wonder about low freq. transmissions of intelligence through the earth is not somehow modulation of seismic like waves instead of being electromagnetic. There is so much to know that we must specialize or we will spend all our lives learning and not have time doing anything before we die. When I was in SONAR we had no computer other than specialized slide rules to compute the ray paths that sound will follow in SeaWater. Today the spoiled young brats in SONAR just need to let the mathematicians/programmers do all the work and push a button to get all their answers. Today They can spend more time Searching/Classifying and Destroying less so computing and understanding. Long Live Computers. ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Sunday, May 21, 2006 9:10 AM Subject: Earthquake sonar software > Hi all > > Is there a software out there that can draw a picture of what earthquake > wave passes trugh ? Something like a sonar type of software. I am not > sure of the this is excaly called in english. I will try to clear this > up if this can't be understand in this email. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > 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: ebay auction From: Bob Barns royb1@........... Date: Mon, 22 May 2006 09:36:03 -0400 Hi gang, BISON INSTRUMENTS SIGNAL ENHANCEMENT SEISMOGRAPH Item number: 7622175542 ends May 28 Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, From: George Bush ke6pxp@....... Date: Mon, 22 May 2006 10:51:38 -0700 I recieved a nice strong signal fron this event. It is interesting that it was followed by a M6.2 about two hours later just down the Kamchatka pennensula and I didn't detect a thing??? USGS reports: A magnitude 6.3 earthquake NEAR THE E COAST OF KORYAKIA, RUSSIA has occurred at: 60.75N 165.88E Depth 14km Mon May 22 11:11:59 2006 UTC Time: Universal Time (UTC) Mon May 22 11:11:59 2006 Time Near Epicenter Tue May 23 00:11:59 2006 Eastern Daylight Time (EDT) Mon May 22 07:11:59 2006 Central Daylight Time (CDT) Mon May 22 06:11:59 2006 Mountain Daylight Time (MDT) Mon May 22 05:11:59 2006 Pacific Daylight Time (PDT) Mon May 22 04:11:59 2006 Alaska Daylight Time (ADT) Mon May 22 03:11:59 2006 Hawaii Standard Time (HST) Mon May 22 01:11:59 2006 Location with respect to nearby cities: 130 km (80 miles) NE of Il'pyrskiy, Russia (pop N/A) 620 km (385 miles) N of Nikol'skoye, Komandorskiye Ostrova, Rus. 740 km (460 miles) WSW of Anadyr', Russia 6330 km (3930 miles) NNE of MOSCOW, Russia For maps, additional information, and subsequent updates, please consult: http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/usnaap.php . You can go to http://psn.quake.net/cgi-dos/event.exe and see my recordings by clicking on "(GIF Image)" for the event files from Sea Ranch. George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Ooops, M6.3... From: George Bush ke6pxp@....... Date: Mon, 22 May 2006 11:00:23 -0700 I apologize for sending the below message. I meant to send it out to a local list of people who are interested in the quakes that I can detect. But, as you see, even living only 300M away from the ocean, I can still detect some nice events even over the ocean noise. ---------------------------------------------- I recieved a nice strong signal fron this event. It is interesting that it was followed by a M6.2 about two hours later just down the Kamchatka pennensula and I didn't detect a thing??? USGS reports: A magnitude 6.3 earthquake NEAR THE E COAST OF KORYAKIA, RUSSIA has occurred ...snip... George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, From: ian ian@........... Date: Mon, 22 May 2006 19:01:40 +0100 The P wave of the first one jammed my Lehman! When I fixed it an hour later I got the remains of it. :-( http://www.iasmith.com/realtime.htm I did pick up the second one but at a lower signal strength. Cheers Ian Smith George Bush wrote: >I recieved a nice strong signal fron this event. It is interesting that it >was followed by a M6.2 about two hours later just down the Kamchatka >pennensula and I didn't detect a thing??? > >USGS reports: > >A magnitude 6.3 earthquake NEAR THE E COAST OF KORYAKIA, RUSSIA has >occurred at: >60.75N 165.88E Depth 14km Mon May 22 11:11:59 2006 UTC > >Time: Universal Time (UTC) Mon May 22 11:11:59 2006 > Time Near Epicenter Tue May 23 00:11:59 2006 > Eastern Daylight Time (EDT) Mon May 22 07:11:59 2006 > Central Daylight Time (CDT) Mon May 22 06:11:59 2006 > Mountain Daylight Time (MDT) Mon May 22 05:11:59 2006 > Pacific Daylight Time (PDT) Mon May 22 04:11:59 2006 > Alaska Daylight Time (ADT) Mon May 22 03:11:59 2006 > Hawaii Standard Time (HST) Mon May 22 01:11:59 2006 > >Location with respect to nearby cities: > 130 km (80 miles) NE of Il'pyrskiy, Russia (pop N/A) > 620 km (385 miles) N of Nikol'skoye, Komandorskiye Ostrova, Rus. > 740 km (460 miles) WSW of Anadyr', Russia > 6330 km (3930 miles) NNE of MOSCOW, Russia > >For maps, additional information, and subsequent updates, >please consult: > http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/usnaap.php . > >You can go to http://psn.quake.net/cgi-dos/event.exe and see my recordings >by clicking on "(GIF Image)" for the event files from Sea Ranch. > >George >__________________________________________________________ > >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: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 22 May 2006 18:02:44 +0000 Hi Emsc-csem did put this earthquake as a 6.7Mw event, the later one as 6.1mb event. You can get more info on them here, http://www.emsc-csem.org/index.php?page=current&sub=detail&id=IW690;CSEM & http://www.emsc-csem.org/index.php?page=current&sub=detail&id=IW395;CSEM The smaller one was at 186km depth, while the primary earthquake was at depth of 10km. I saw the p wave from the 6.7Mw event, I find that to be unusual. I also think that i did see something from the 6.1mb event, but it is unclear at the moment. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 22 May 2006 18:26:42 +0000 Hi all I am having a bit of a problem. I more often then not I get a one single line spike into my earthquake recording, those spikes can be seen on my online tremor plots. I wonder if there might be some explantion for these spikes. The wire that i use to connect to the amplifer board is near alot of electronic hardware, tv, vcr, sky digital box, subscription tv box for local channel (is going to get removed soon), tvoadsl tv decoder box. Becose of my location, i can't change the path of the wire. If that is the source of this problem. Any suggestion on this welcomed. Also, I am going to move to GPS time kepping tomorrow, so time errors are history for me. :-) Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Extending coax on Motorola Oncore GPS antenna From: apsn apsn@........... Date: Mon, 22 May 2006 11:16:49 -0800 I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a location such that I need to add 50' of coax. What do you suggest for coax and where can I find adapters for that tiny right-angle MMCX connector? Thanks, Bob Hammond Public Seismic Network - Alaska http://apsn.awcable.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, RUSSIA From: "Geoffrey" gmvoeth@........... Date: Mon, 22 May 2006 12:28:02 -0700 Hey, Dont blame it on the P wave of a teleseism. You obviously have some mechanical defect in your device. ----- Original Message ----- From: "ian" To: Sent: Monday, May 22, 2006 11:01 AM Subject: Re: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, RUSSIA > The P wave of the first one jammed my Lehman! When I fixed it an hour > later I got the remains of it. :-( > http://www.iasmith.com/realtime.htm > > I did pick up the second one but at a lower signal strength. > > Cheers > > Ian Smith > > George Bush wrote: > >>I recieved a nice strong signal fron this event. It is interesting that it >>was followed by a M6.2 about two hours later just down the Kamchatka >>pennensula and I didn't detect a thing??? >> >>USGS reports: >> >>A magnitude 6.3 earthquake NEAR THE E COAST OF KORYAKIA, RUSSIA has >>occurred at: >>60.75N 165.88E Depth 14km Mon May 22 11:11:59 2006 UTC >> >>Time: Universal Time (UTC) Mon May 22 11:11:59 2006 >> Time Near Epicenter Tue May 23 00:11:59 2006 >> Eastern Daylight Time (EDT) Mon May 22 07:11:59 2006 >> Central Daylight Time (CDT) Mon May 22 06:11:59 2006 >> Mountain Daylight Time (MDT) Mon May 22 05:11:59 2006 >> Pacific Daylight Time (PDT) Mon May 22 04:11:59 2006 >> Alaska Daylight Time (ADT) Mon May 22 03:11:59 2006 >> Hawaii Standard Time (HST) Mon May 22 01:11:59 2006 >> >>Location with respect to nearby cities: >> 130 km (80 miles) NE of Il'pyrskiy, Russia (pop N/A) >> 620 km (385 miles) N of Nikol'skoye, Komandorskiye Ostrova, Rus. >> 740 km (460 miles) WSW of Anadyr', Russia >> 6330 km (3930 miles) NNE of MOSCOW, Russia >> >>For maps, additional information, and subsequent updates, >>please consult: >> http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/usnaap.php . >> >>You can go to http://psn.quake.net/cgi-dos/event.exe and see my recordings >>by clicking on "(GIF Image)" for the event files from Sea Ranch. >> >>George >>__________________________________________________________ >> >>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: Extending coax on Motorola Oncore GPS antenna From: apsn apsn@........... Date: Mon, 22 May 2006 11:34:16 -0800 OR, has anyone moved their Motorola Oncore GPS engine and antenna to a remote spot (waterproofed, of course) and used a long run of RS-232 cable plus power back to the digitizer board? This is similar to what Motorola or Synergy Systems sells in their Timing2000 product. >Date: Mon, 22 May 2006 11:16:49 -0800 >To: psn-l@.............. >From: apsn >Subject: Extending coax on Motorola Oncore GPS antenna > >I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a >location such that I need to add 50' of coax. What do you suggest >for coax and where can I find adapters for that tiny right-angle >MMCX connector? > >Thanks, > >Bob Hammond >Public Seismic Network - Alaska >http://apsn.awcable.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF From: John or Jan Lahr JohnJan@........ Date: Mon, 22 May 2006 13:09:46 -0700 Hi J=F3n and others, The USGS NEIC has a replacement for the old=20 Bigquake E-mail system that is good for quick earthquake notification. The system allows=20 each user to specify which events are of interest. One can subscribe here: = http://earthquake.usgs.gov/eqcenter/ens/ Cheers, John At 11:02 AM 5/22/2006, J=F3n wrote: >Hi > >Emsc-csem did put this earthquake as a 6.7Mw event, the later one as >6.1mb event. You can get more info on them here ... __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, RUSSIA From: "Bob Hancock" carpediem1@......... Date: Mon, 22 May 2006 14:04:21 -0700 Hi All - There are multiple formulas used to determine magnitude. The magnitudes determined by Harvard and NEIC often do not match and according to John Lahr, the "Official" magnitude of an event is the greater of either Harvard or NEIC. Maybe John Lahr would comment on the magnitudes derived from other sources such as the European-Mediterranean Seismic Center (EMSC) and how they affect the "Official" magnitude of an event. On the first event the magnitudes were: 6.7 - EMSC; 6.6 - Harvard; and 6.5 NEIC On the second event the magnitudes were 6.1 - EMSC; 6.2 - Harvard; and 6.2 NEIC Using the extremes 6.7 and 6.1 the seismic wave amplitude of the second event would be 0.251 of the first event, and the radiated seismic energy would be 0.125 of the first event. Using the NEIC numbers 6.6 and 6.2, the seismic wave amplitude of the second event would be 0.251 of the first event, and the radiated seismic energy would be 0.251 of the first event. Add to this the fact that the first event was shallow at 11.1 km, while the second event was deep at 189.4 km - the depth would reduce the effects of the Love and Rayleigh waves. Another factor would be the natural seismic noise that would be present with a location 3.14 miles from the ocean. The event would have to be greater than the lowest level of detection, a factor of the seismometer sensitivity and background noise. The formulas for computing the difference follow: FM = First Magnitude SM = Second Magnitude M1A = 10 ^ FM M1B = 10 ^ SM Seismic Wave Amplitude Diff = M1B / M1A Radiated Seismic Energy Diff = 10 ^ ((SM - FM) * 1.5) Thanks to John Lahr for his help in putting these formulas together. Bob Hancock Three Points, AZ -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of George Bush Sent: Monday, May 22, 2006 10:52 To: Recipient list suppressed : Subject: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, RUSSIA I recieved a nice strong signal fron this event. It is interesting that it was followed by a M6.2 about two hours later just down the Kamchatka pennensula and I didn't detect a thing??? USGS reports: A magnitude 6.3 earthquake NEAR THE E COAST OF KORYAKIA, RUSSIA has occurred at: 60.75N 165.88E Depth 14km Mon May 22 11:11:59 2006 UTC Time: Universal Time (UTC) Mon May 22 11:11:59 2006 Time Near Epicenter Tue May 23 00:11:59 2006 Eastern Daylight Time (EDT) Mon May 22 07:11:59 2006 Central Daylight Time (CDT) Mon May 22 06:11:59 2006 Mountain Daylight Time (MDT) Mon May 22 05:11:59 2006 Pacific Daylight Time (PDT) Mon May 22 04:11:59 2006 Alaska Daylight Time (ADT) Mon May 22 03:11:59 2006 Hawaii Standard Time (HST) Mon May 22 01:11:59 2006 Location with respect to nearby cities: 130 km (80 miles) NE of Il'pyrskiy, Russia (pop N/A) 620 km (385 miles) N of Nikol'skoye, Komandorskiye Ostrova, Rus. 740 km (460 miles) WSW of Anadyr', Russia 6330 km (3930 miles) NNE of MOSCOW, Russia For maps, additional information, and subsequent updates, please consult: http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/usnaap.php . You can go to http://psn.quake.net/cgi-dos/event.exe and see my recordings by clicking on "(GIF Image)" for the event files from Sea Ranch. George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Mon, 22 May 2006 18:39:15 EDT In a message dated 22/05/2006, jonfr500@......... writes: I more often then not I get a one single line spike into my earthquake recording, those spikes can be seen on my online tremor plots. The wire that i use to connect to the amplifer board is near alot of electronic hardware, tv, vcr, sky digital box, subscription tv box for local channel, tvo adsl tv decoder box. Hi Jon, One of the common causes of spikes may be the inductive motor of your refrigerator switching on and off. It is likely to effect the whole of the house wiring and can be difficult to eliminate. Try switching your fridge on and off to see if there are spikes? You can buy the Electrolux type fridge which just has an electric / gas heater to drive it - no motor. Regards, Chris Chapman
In a message dated 22/05/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I more=20 often then not I get a one single line spike into my earthquake recording,= =20 those spikes can be seen on my online tremor plots. The wire that i use to= =20 connect to the amplifer board is near alot of electronic hardware, tv, vcr= ,=20 sky digital box, subscription tv box for local channel, tvo adsl tv decode= r=20 box.
Hi Jon,
 
    One of the common causes of spikes may be the=20 inductive motor of your refrigerator switching on and off. It is likely= to=20 effect the whole of the house wiring and can be difficult to=20 eliminate. Try switching your fridge on and off to see if there are spikes?=20
    You can buy the Electrolux type fridge which ju= st=20 has an electric / gas heater to drive it - no motor.
 
    Regards,
 
    Chris Chapman
 Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 22 May 2006 22:48:01 +0000 Hi Chris. I live in a block, and there are 7 other apartment close to mine. So if it is some motor in a refrigerator, it is problay not mine, I think, it can also be my refrigerator, but i don't think i will eliminate the problem. Becose there are other apartments near me. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Extending coax on Motorola Oncore GPS antenna From: Stephen & Kathy skmort@............ Date: Mon, 22 May 2006 18:49:24 -0700 Hi,, I simply clipped the antenna cable close to the antenna and soldered RG58U (what ever the 50 ohm number is), cable to it! I used a short piece of the RG58 interior insulation and sloped it to match the 174 to cover the solder connection, then folded the outside conductor, from each cable, over it, taped it, and waterproofed it!! About 10 feet went up the pole where the antenna sits,, about 10 feet went through the attic with about a foot down from the ceiling where it is connected to the GPS, (GPS is still indoors), then about 30 feet of RS232 to the computer! I use telephone cable and connectors for the GPS power and one second data! I get strong satellite signals, even with the cable diameter mismatch! Just my two cents worth of experience!! Stephen PSN Station #55 near Pilot Hill Ca. USA 38.828N 120.979W apsn wrote: > OR, has anyone moved their Motorola Oncore GPS engine and antenna to a > remote spot (waterproofed, of course) and used a long run of RS-232 > cable plus power back to the digitizer board? This is similar to what > Motorola or Synergy Systems sells in their Timing2000 product. > > >> Date: Mon, 22 May 2006 11:16:49 -0800 >> To: psn-l@.............. >> From: apsn >> Subject: Extending coax on Motorola Oncore GPS antenna >> >> I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a >> location such that I need to add 50' of coax. What do you suggest >> for coax and where can I find adapters for that tiny right-angle MMCX >> connector? >> >> Thanks, >> >> Bob Hammond >> Public Seismic Network - Alaska >> http://apsn.awcable.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: Extending coax on Motorola Oncore GPS antenna From: apsn apsn@........... Date: Mon, 22 May 2006 20:49:09 -0800 Thanks, Stephen. At 05:00 PM 5/22/2006, you wrote: >Hi,, I simply clipped the antenna cable close to the antenna and >soldered RG58U (what ever the 50 ohm number is), cable to it! I >used a short piece of the RG58 interior insulation and sloped it to >match the 174 to cover the solder connection, then folded the >outside conductor, from each cable, over it, taped it, and >waterproofed it!! About 10 feet went up the pole where the antenna >sits,, about 10 feet went through the attic with about a foot down >from the ceiling where it is connected to the GPS, (GPS is still >indoors), then about 30 feet of RS232 to the computer! I use >telephone cable and connectors for the GPS power and one second >data! I get strong satellite signals, even with the cable diameter mismatch! > >Just my two cents worth of experience!! > > Stephen > PSN Station #55 > near Pilot Hill Ca. USA > 38.828N 120.979W > >apsn wrote: >>OR, has anyone moved their Motorola Oncore GPS engine and antenna >>to a remote spot (waterproofed, of course) and used a long run of >>RS-232 cable plus power back to the digitizer board? This is >>similar to what Motorola or Synergy Systems sells in their Timing2000 product. >> >> >>>Date: Mon, 22 May 2006 11:16:49 -0800 >>>To: psn-l@.............. >>>From: apsn >>>Subject: Extending coax on Motorola Oncore GPS antenna >>> >>>I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a >>>location such that I need to add 50' of coax. What do you suggest >>>for coax and where can I find adapters for that tiny right-angle >>>MMCX connector? >>> >>>Thanks, >>> >>>Bob Hammond >>>Public Seismic Network - Alaska >>>http://apsn.awcable.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) > >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: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF From: George Bush ke6pxp@....... Date: Tue, 23 May 2006 09:21:30 -0700 Ian- I am glad you at least got the second one! I assume that the reason that I didn't was that it was masked my the ocean noise due to my location. At 07:01 PM 5/22/06 +0100, you wrote: >The P wave of the first one jammed my Lehman! When I fixed it an hour >later I got the remains of it. :-( >http://www.iasmith.com/realtime.htm > >I did pick up the second one but at a lower signal strength. > >Cheers > >Ian Smith > George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Extending coax on Motorola Oncore GPS antenna From: George Bush ke6pxp@....... Date: Tue, 23 May 2006 09:35:19 -0700 To make my GPS card work, I had to move it to an upper window and mount the antenna outside. This required about 50' of RS-232 cable. To minimize cables and power supplys, I used two wires in the RS-232 cable for the GPS power which I tapped from the data-acquisition computer. It has been working fine for years. At 11:34 AM 5/22/06 -0800, you wrote: >OR, has anyone moved their Motorola Oncore GPS engine and antenna to >a remote spot (waterproofed, of course) and used a long run of RS-232 >cable plus power back to the digitizer board? This is similar to >what Motorola or Synergy Systems sells in their Timing2000 product. > > George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Extending coax on Motorola Oncore GPS antenna From: "Geoffrey" gmvoeth@........... Date: Tue, 23 May 2006 10:42:56 -0700 Can you tell me the frequency traveling in the coaxial cable ? According to the 2004 ARRL handbook your losses in an RG8 cable with foam insulation at 100MHz will be about 1.7db per 100 feet of cable 500MHz will be about 4db per 100 feet if you are using some other kind of dielectric the losses might be almost twice that. the velocity factor varies according to the manufacturer but varies somewhere between 82% and 86% speed of light for cables with outside diameters in the range of 0.2 - 0.24 inches. You can use this number to trim the cable to the proper multiple ot partial multiple of a wavelength. I have found RG8 to be the best cable to use when connecting the front end of a receiver directly to an antenna. Most antennas have a very low impedance 50 ohms or less in the case of Yagi-Uda. You can match impedance's using various techniques and you can place ferrite beads near both ends of the cable to isolate signals on the outside/inside of the shield. The study of antennas and transmission lines is everybit as interesting as seismology itself. What is a geophone but a kind of electro mechanical antenna. ----- Original Message ----- From: "Stephen & Kathy" To: Sent: Monday, May 22, 2006 6:49 PM Subject: Re: Extending coax on Motorola Oncore GPS antenna > Hi,, I simply clipped the antenna cable close to the antenna and > soldered RG58U (what ever the 50 ohm number is), cable to it! I used a > short piece of the RG58 interior insulation and sloped it to match the > 174 to cover the solder connection, then folded the outside conductor, > from each cable, over it, taped it, and waterproofed it!! About 10 feet > went up the pole where the antenna sits,, about 10 feet went through the > attic with about a foot down from the ceiling where it is connected to > the GPS, (GPS is still indoors), then about 30 feet of RS232 to the > computer! I use telephone cable and connectors for the GPS power and > one second data! I get strong satellite signals, even with the cable > diameter mismatch! > > Just my two cents worth of experience!! > > Stephen > PSN Station #55 > near Pilot Hill Ca. USA > 38.828N 120.979W > > apsn wrote: >> OR, has anyone moved their Motorola Oncore GPS engine and antenna to a >> remote spot (waterproofed, of course) and used a long run of RS-232 >> cable plus power back to the digitizer board? This is similar to what >> Motorola or Synergy Systems sells in their Timing2000 product. >> >> >>> Date: Mon, 22 May 2006 11:16:49 -0800 >>> To: psn-l@.............. >>> From: apsn >>> Subject: Extending coax on Motorola Oncore GPS antenna >>> >>> I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a >>> location such that I need to add 50' of coax. What do you suggest >>> for coax and where can I find adapters for that tiny right-angle MMCX >>> connector? >>> >>> Thanks, >>> >>> Bob Hammond >>> Public Seismic Network - Alaska >>> http://apsn.awcable.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) > > 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: Extending coax on Motorola Oncore GPS antenna From: "James Hannon" jmhannon@......... Date: Tue, 23 May 2006 13:02:32 -0500 The GPS frequency is 1575.42 MHz. Line loss for 50 feet of RG58 at this frequency is around 10 dB. RG58 is not really recommended for microwaves! Jim Hannon ---------- Original Message ---------------------------------- From: "Geoffrey" Reply-To: psn-l@.............. Date: Tue, 23 May 2006 10:42:56 -0700 >Can you tell me the frequency traveling >in the coaxial cable ? > >According to the 2004 ARRL handbook your losses >in an RG8 cable with foam insulation at >100MHz will be about 1.7db per 100 feet of cable >500MHz will be about 4db per 100 feet >if you are using some other kind of dielectric >the losses might be almost twice that. > >the velocity factor varies according to >the manufacturer but varies somewhere >between 82% and 86% speed of light >for cables with outside diameters in the range of >0.2 - 0.24 inches. You can use this number to trim >the cable to the proper multiple ot partial multiple >of a wavelength. > >I have found RG8 to be the best cable to use >when connecting the front end of a receiver >directly to an antenna. > >Most antennas have a very low impedance >50 ohms or less in the case of Yagi-Uda. > >You can match impedance's using various techniques >and you can place ferrite beads near both ends of the cable >to isolate signals on the outside/inside of the shield. > >The study of antennas and transmission lines >is everybit as interesting as seismology itself. >What is a geophone but a kind of electro mechanical antenna. > > >----- Original Message ----- >From: "Stephen & Kathy" >To: >Sent: Monday, May 22, 2006 6:49 PM >Subject: Re: Extending coax on Motorola Oncore GPS antenna > > >> Hi,, I simply clipped the antenna cable close to the antenna and >> soldered RG58U (what ever the 50 ohm number is), cable to it! I used a >> short piece of the RG58 interior insulation and sloped it to match the >> 174 to cover the solder connection, then folded the outside conductor, >> from each cable, over it, taped it, and waterproofed it!! About 10 feet >> went up the pole where the antenna sits,, about 10 feet went through the >> attic with about a foot down from the ceiling where it is connected to >> the GPS, (GPS is still indoors), then about 30 feet of RS232 to the >> computer! I use telephone cable and connectors for the GPS power and >> one second data! I get strong satellite signals, even with the cable >> diameter mismatch! >> >> Just my two cents worth of experience!! >> >> Stephen >> PSN Station #55 >> near Pilot Hill Ca. USA >> 38.828N 120.979W >> >> apsn wrote: >>> OR, has anyone moved their Motorola Oncore GPS engine and antenna to a >>> remote spot (waterproofed, of course) and used a long run of RS-232 >>> cable plus power back to the digitizer board? This is similar to what >>> Motorola or Synergy Systems sells in their Timing2000 product. >>> >>> >>>> Date: Mon, 22 May 2006 11:16:49 -0800 >>>> To: psn-l@.............. >>>> From: apsn >>>> Subject: Extending coax on Motorola Oncore GPS antenna >>>> >>>> I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a >>>> location such that I need to add 50' of coax. What do you suggest >>>> for coax and where can I find adapters for that tiny right-angle MMCX >>>> connector? >>>> >>>> Thanks, >>>> >>>> Bob Hammond >>>> Public Seismic Network - Alaska >>>> http://apsn.awcable.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) >> >> 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. > -- Jim Hannon http://www.fmtcs.com/web/jmhannon/ 42,11.90N,91,39.26W WB0TXL -- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Extending coax on Motorola Oncore GPS antenna From: ChrisAtUpw@....... Date: Tue, 23 May 2006 14:46:35 EDT In a message dated 22/05/2006, apsn@........... writes: I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a location such that I need to add 50' of coax. What do you suggest for coax and where can I find adapters for that tiny right-angle MMCX connector? Hi Bob, Do you have to extend the aerial co-ax at all? Can you not site the aerial + receiver remotely and extend the cable connecting it to the computer? The problems of RS232 connection are likely to be minimal up to 50 m. Hi grade low loss UHF cable tends to be expensive. I note that the web suppliers tend only to sell cable by the 100ft minimum. Regards, Chris Chapman
In a message dated 22/05/2006, apsn@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I need=20 to move my GPS antenna (Oncore GPS for WinSDR timing) to a
location su= ch=20 that I need to add 50' of coax.  What do you suggest
for coax and= =20 where can I find adapters for that tiny right-angle MMCX=20
connector?
Hi Bob,
 
    Do you have to extend the aerial co-ax at all?=20= Can=20 you not site the aerial + receiver remotely and extend the cable connecting=20= it=20 to the computer?
    The problems of RS232 connection are likely to=20= be=20 minimal up to 50 m. Hi grade low loss UHF cable tends to be expensive. I not= e=20 that the web suppliers tend only to sell cable by the 100ft minimum.
 
    Regards,
 
    Chris Chapman
 
 Subject: Re: Extending coax on Motorola Oncore GPS antenna From: apsn apsn@........... Date: Tue, 23 May 2006 14:19:14 -0800 Thanks everyone for your ideas. I have lots of shielded cable for a serial connection and don't want to buy LMR600 low loss coax at a $1+ a foot! Bob At 10:46 AM 5/23/2006, you wrote: >In a message dated 22/05/2006, apsn@........... writes: >I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a >location such that I need to add 50' of coax. What do you suggest >for coax and where can I find adapters for that tiny right-angle MMCX >connector? > >Hi Bob, > > Do you have to extend the aerial co-ax at all? Can you not site > the aerial + receiver remotely and extend the cable connecting it > to the computer? > The problems of RS232 connection are likely to be minimal up to > 50 m. Hi grade low loss UHF cable tends to be expensive. I note > that the web suppliers tend only to sell cable by the 100ft minimum. > > Regards, > > Chris Chapman > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Extending coax on Motorola Oncore GPS antenna From: "Jan Marshall" jandmarshall@............ Date: Tue, 23 May 2006 18:32:27 -0600 I have had NO problem extending my GPS antenna 50 feet using a low-loss cable the size of RG59. Also I have found all kinds of coax fittings on eBay -- most for a song. Jan Marshall Nampa, Idaho, USA jandmarshall@............ -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of apsn Sent: Tuesday, May 23, 2006 4:19 PM To: psn-l@.............. Subject: Re: Extending coax on Motorola Oncore GPS antenna Thanks everyone for your ideas. I have lots of shielded cable for a serial connection and don't want to buy LMR600 low loss coax at a $1+ a foot! Bob At 10:46 AM 5/23/2006, you wrote: >In a message dated 22/05/2006, apsn@........... writes: >I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a >location such that I need to add 50' of coax. What do you suggest for >coax and where can I find adapters for that tiny right-angle MMCX >connector? > >Hi Bob, > > Do you have to extend the aerial co-ax at all? Can you not site > the aerial + receiver remotely and extend the cable connecting it > to the computer? > The problems of RS232 connection are likely to be minimal up to > 50 m. Hi grade low loss UHF cable tends to be expensive. I note > that the web suppliers tend only to sell cable by the 100ft minimum. > > Regards, > > Chris Chapman > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: GPS location avarge From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 24 May 2006 15:35:37 +0000 Hi all I got my garmin gps antenna today. How many days do i have to keep it on "GPS Location" to get farly accure location for WinSDR ? Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: M6.3 5327km from Sea Ranch, CA USA, NEAR E COAST OF KORYAKIA, From: ian ian@........... Date: Wed, 24 May 2006 19:44:18 +0100 Hi, I'm probably a bit closer, Russia just being a short hop over the North Pole from here, sort of. Cheers Ian George Bush wrote: >Ian- > >I am glad you at least got the second one! I assume that the reason that I >didn't was that it was masked my the ocean noise due to my location. > >At 07:01 PM 5/22/06 +0100, you wrote: > > >>The P wave of the first one jammed my Lehman! When I fixed it an hour >>later I got the remains of it. :-( >>http://www.iasmith.com/realtime.htm >> >>I did pick up the second one but at a lower signal strength. >> >>Cheers >> >>Ian Smith >> >> >> > >George >__________________________________________________________ > >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,

I'm probably a bit closer, Russia just being a short hop over the North Pole from here, sort of.

Cheers

Ian

George Bush wrote:
Ian-

I am glad you at least got the second one! I assume that the reason that I
didn't was that it was masked my the ocean noise due to my location.

At 07:01 PM 5/22/06 +0100, you wrote:
  
The P wave of the first one jammed my Lehman!  When I fixed it an hour 
later I got the remains of it.  :-( 
http://www.iasmith.com/realtime.htm

I did pick up the second one but at a lower signal strength.

Cheers

Ian Smith

    

George
__________________________________________________________

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: GPS location avarge From: Larry Cochrane lcochrane@.............. Date: Wed, 24 May 2006 20:19:49 -0700 Hi Jón, Probably a few hours is all that is needed but I would let WinSDR average the data for a day or two. Regards, Larry Cochrane Redwood City, PSN Jón Frímann wrote: > Hi all > > I got my garmin gps antenna today. How many days do i have to keep it on > "GPS Location" to get farly accure location for WinSDR ? > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 26 May 2006 12:24:39 +0000 Hi all Is there any way for me to reduse the spike problem that I am having ? I can draw up the current setup to explain the problem if needed. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Fri, 26 May 2006 11:35:47 EDT In a message dated 26/05/06, jonfr500@......... writes: > Is there any way for me to reduce the spike problem that I am having? > I can draw up the current setup to explain the problem if needed. Hi Jon, How many spikes do you see per hour and are they a ~single pulse or several? What sizes are they? Is the size very variable? Are there any particular times over 24 hrs when the interference is more severe? Spikes on a quake trace are often due to pulses on the electricity supply in the house. Refrigerators which have an electric motor can put large spikes on the system as they turn on and off. If you have a fridge of this type, note when it turns on and off - maybe also try switching it with a wall socket switch - and look for spikes on the trace. Do you have electric heating in the house controlled by time clocks / thermostats? Since you live in a block of houses, you may also pick up local interference from other users. You can also get large spikes on the electricity supply if there are any 'industrial' users nearby. Large electric motors and electric welding are common sources within several km. They may also be due to switching between electricity generating plant and this can effect wide areas. It is often observed as a momentary dimming of electric light bulbs and the momentary failure of 1 to 2 m long strip light tubes. The normal method is to provide protection against transient spikes with a filter on the supply system and to provide large electrolytic storage capacitors on your power supplies. This enables the amplifier rail voltages to remain constant during a momentary power failure. Do you have house power wiring with three of just two connecting pins, and what voltage is it? You can also buy 'uninterruptable power supplies' for computers and similar low power equipment. These have an auxiliary 12/24 V backup lead acid battery which keeps the systems running during short power failures. Switch over time is about 1/2 a supply power cycle, 1/100 or 1/120 second. They may have a data link to the computer to enable it to save data / close down automatically. What sort of power supplies are you using for your amplifiers and are the common 0 V rails on amplifier boards effectively earthed at the signal input pins? Do you get much lightning? Regards, Chris Chapman In a message=20= dated 26/05/06, jonfr500@......... writes:

Is there any way for me to=20= reduce the spike problem that I am having?
I can draw up the current setup to explain the problem if needed.=

Hi Jon,=20

      How many spikes do you see per hour= and are they a ~single pulse or several?  What sizes are they? Is the=20= size very variable? Are there any particular times over 24 hrs when the inte= rference is more severe?

      Spikes on a quake trace are often d= ue to pulses on the electricity supply in the house. Refrigerators which hav= e an electric motor can put large spikes on the system as they turn on and o= ff. If you have a fridge of this type, note when it turns on and off - maybe= also try switching it with a wall socket switch - and look for spikes on th= e trace. Do you have electric heating in the house controlled by time clocks= / thermostats? Since you live in a block of houses, you may also pick up lo= cal interference from other users.=20

      You can also get large spikes on th= e electricity supply if there are any 'industrial' users nearby. Large elect= ric motors and electric welding are common sources within several km.  

      They may also be due to switching b= etween electricity generating plant and this can effect wide areas. It is of= ten observed as a momentary dimming of electric light bulbs and the momentar= y failure of 1 to 2 m long strip light tubes.

      The normal method is to provide pro= tection against transient spikes with a filter on the supply system and to p= rovide large electrolytic storage capacitors on your power supplies. This en= ables the amplifier rail voltages to remain constant during a momentary powe= r failure.

      Do you have house power wiring with= three of just two connecting pins, and what voltage is it?  

      You can also buy 'uninterruptable p= ower supplies' for computers and similar low power equipment. These have an=20= auxiliary 12/24 V backup lead acid battery which keeps the systems running d= uring short power failures. Switch over time is about 1/2 a supply power cyc= le, 1/100 or 1/120 second. They may have a data link to the computer to enab= le it to save data / close down automatically.=20

      What sort of power supplies are you= using for your amplifiers and are the common 0 V rails on amplifier boards=20= effectively earthed at the signal input pins?   

      Do you get much lightning?

      Regards,

      Chris Chapman Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 26 May 2006 16:40:36 +0000 Hi Chris Q: How many spikes do you see per hour and are they a ~single pulse or several? A: There are several spikes pr hours, this is sigle pulse. They can be seen on my online tremor plots. Q: What sizes are they? A: There size is variable, the largest one are few mm in size. There is a diffrent between grund spikes (pepole, traffic etc..) then these single spikes. Q: Are there any particular times over 24 hrs when the interference is more severe? A: This spikes happens mostly over the day, however I have seen them late night and during the night. Even when the traffic noise is minimal. I don't know if my fridge has electronic motor. It has tank like item in it. But it problay is a motor. > You can also get large spikes on the electricity supply if there are > any 'industrial' users nearby. Large electric motors and electric > welding are common sources within several km. There is a factory few meters (around 200 - 500 meters) away from me. They do use heavy electronic hardware, but i don't think that is the problem. Since the electronic system is good and farly new (~20 year old). > They may also be due to switching between electricity generating plant > and this can effect wide areas. It is often observed as a momentary > dimming of electric light bulbs and the momentary failure of 1 to 2 m > long strip light tubes. Only time I see dimming of electonic light bulbs is during winter storms that hit the electronic grid in Iceland hard. Over the summer this almost never happen, unless there is a failure in the electronic grid. > The normal method is to provide protection against transient spikes > with a filter on the supply system and to provide large electrolytic > storage capacitors on your power supplies. This enables the amplifier > rail voltages to remain constant during a momentary power failure. I plan to buy UPS with the computer and the WinSDR board, so it can work if i loose power during winter storms or if something else goes wrong. I just don't know when I can buy it. Q: Do you have house power wiring with three of just two connecting pins, and what voltage is it? There are three wires, two for electronic and one for ground. This is two phase electronic power system that I use, Iceland uses 220v/50Hz. I also have a 10 amp electronic fuse. With that the apartment is also breaked down to 5 parts, each haveing it's own power fuse, larger electronic have larger fuse, 16 amps and 25 amps the larger ones. > You can also buy 'uninterruptable power supplies' for computers and > similar low power equipment. These have an auxiliary 12/24 V backup > lead acid battery which keeps the systems running during short power > failures. Switch over time is about 1/2 a supply power cycle, 1/100 or > 1/120 second. They may have a data link to the computer to enable it > to save data / close down automatically. I plan to, I just don't know when I can afford it. Q: What sort of power supplies are you using for your amplifiers and are the common 0 V rails on amplifier boards effectively earthed at the signal input pins? A: I am using the power converter that Larry did sell me. It has been working without a problem. Other then that, I don't know. Q: Do you get much lightning? A: No, it sometimes happen during the summer and last week has been clear of any lightings in Iceland. Here is what I did when the problem did start happening. Becose of my small place in my apartment, I had the wire from the geophone on the floor to start with. But two weeks ago, I did remove the wire off the floor with a list and put it near the sealing (or however it is spelled). Then the problem started to happening. It might be that the wire did act like a antenna, but I am not sure. For testing i did put the wire back down to the floor to see what happens in the next week, in order to get some comparision. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Extending coax on Motorola Oncore GPS antenna From: apsn apsn@........... Date: Sat, 27 May 2006 17:50:31 -0800 Hi all, I extended my GPS antenna cable today using two 50 ft sections of very old ratty RG-8 I found in my stuff and coupled them together with a PL-259 bullet. I've got an MMCX to BNC to PL-259 on the receiver end and a PL-259 to BNC on the antenna end! All satellite signal strengths are 35 and above. I am amazed I got any signal strength at all. Maybe I'll try some garden hose next. thanks for all the input, Bob Public Seismic Network - Alaska http://apsn.awcable.com At 04:32 PM 5/23/2006, you wrote: >I have had NO problem extending my GPS antenna 50 feet using a low-loss >cable the size of RG59. Also I have found all kinds of coax fittings on >eBay -- most for a song. > >Jan Marshall >Nampa, Idaho, USA >jandmarshall@............ > > > > >-----Original Message----- >From: psn-l-request@.............. [mailto:psn-l-request@............... >On Behalf Of apsn >Sent: Tuesday, May 23, 2006 4:19 PM >To: psn-l@.............. >Subject: Re: Extending coax on Motorola Oncore GPS antenna > > >Thanks everyone for your ideas. I have lots of shielded cable for a >serial connection and don't want to buy LMR600 low loss coax at a $1+ a >foot! > >Bob > >At 10:46 AM 5/23/2006, you wrote: > >In a message dated 22/05/2006, apsn@........... writes: > >I need to move my GPS antenna (Oncore GPS for WinSDR timing) to a > >location such that I need to add 50' of coax. What do you suggest for > >coax and where can I find adapters for that tiny right-angle MMCX > >connector? > > > >Hi Bob, > > > > Do you have to extend the aerial co-ax at all? Can you not site > > the aerial + receiver remotely and extend the cable connecting it > > to the computer? > > The problems of RS232 connection are likely to be minimal up to > > 50 m. Hi grade low loss UHF cable tends to be expensive. I note > > that the web suppliers tend only to sell cable by the 100ft minimum. > > > > Regards, > > > > Chris Chapman > > > >__________________________________________________________ > >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: Did anyone record norwegian sea earthquake ? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 28 May 2006 23:49:41 +0000 Hi all Did anyone here record this earthquake ? It's size was 5.1mb according to emsc-csem. http://www.emsc-csem.org/index.php?page=current&sub=detail&id=IY374;INFO I was not able to record it, becose of the distance from my location and the geophone. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Did anyone record norwegian sea earthquake ? From: "Geoffrey" gmvoeth@........... Date: Tue, 30 May 2006 05:28:00 -0700 When You talk about any EQ could you please include the Date Time UT in the text of your letters ? I would like to be able to identify things a year later and these web sites do not always live that long. ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Sunday, May 28, 2006 4:49 PM Subject: Did anyone record norwegian sea earthquake ? > Hi all > > Did anyone here record this earthquake ? It's size was 5.1mb according > to emsc-csem. > http://www.emsc-csem.org/index.php?page=current&sub=detail&id=IY374;INFO > > I was not able to record it, becose of the distance from my location and > the geophone. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > 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: Did anyone record norwegian sea earthquake ? From: ChrisAtUpw@....... Date: Tue, 30 May 2006 09:51:30 EDT In a message dated 30/05/2006 13:28:28 GMT Daylight Time, gmvoeth@........... writes: When You talk about any EQ could you please include the Date Time UT in the text of your letters ? I would like to be able to identify things a year later and these web sites do not always live that long. There was only one. 28-MAY-2006 13:23:29 74.09 13.53 5.2 10.0 NORWEGIAN SEA
In a message dated 30/05/2006 13:28:28 GMT Daylight Time,=20 gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>When You=20 talk about any EQ could you please
include the Date Time UT in the text= of=20 your
letters ? I would like to be able to identify things
a year lat= er=20 and these web sites do not always
live that=20 long.
There was only one.
 
28-MAY-2006 13:23:29 74.09 13.53 5.2 10.0 NORWEGIAN=20 SEA
 Subject: Recording from unknown source From: Roger Sparks rsparks@.......... Date: Tue, 30 May 2006 17:28:11 -0700 Hello All, I and* ELL SHZ UW : Ellensburg, WA* recorded an event, but none of the other Washington seismic stations on the web recorded it. I am wondering what it might be? My recording is at http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/060530.165536.ebgz.psn The UW recording is at http://www.pnsn.org/WEBICORDER/PNSN/ELL_SHZ_UW.2006053012.html I do not know exactly where *ELL SHZ UW : Ellensburg, WA* is located but I believe it is 5 or more miles away. I wonder if it might be a meteor? Roger __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Recording from unknown source From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 31 May 2006 00:49:36 +0000 Hi This is really strange signal. Check this webpage for meteor info, http://www.spaceweather.com/ But earth is passing trugh a debre from the remains of the comet 73P/Schwassmann Wachmann 3. I don't have time to check this signal at the moment, I am going to try to check it tomorrow. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Recording from unknown source From: apsn apsn@........... Date: Tue, 30 May 2006 16:55:10 -0800 Roger, Your waveform, and that of station ELL, looks like a regional earthquake to me. regards, Bob Hammond PSN - Alaska http://apsn.awcable.com At 03:34 PM 5/30/2006, you wrote: >Hello All, > >I and* ELL SHZ UW : Ellensburg, WA* recorded an event, but none of >the other Washington seismic stations on the web recorded it. I am >wondering what it might be? > >My recording is at >http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/060530.165536.ebgz.psn > >The UW recording is at >http://www.pnsn.org/WEBICORDER/PNSN/ELL_SHZ_UW.2006053012.html > >I do not know exactly where *ELL SHZ UW : Ellensburg, WA* is located >but I believe it is 5 or more miles away. > >I wonder if it might be a meteor? > >Roger >__________________________________________________________ > >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: Recording from unknown source From: ChrisAtUpw@....... Date: Tue, 30 May 2006 21:07:28 EDT In a message dated 31/05/2006, rsparks@.......... writes: I and* ELL SHZ UW : Ellensburg, WA* recorded an event, but none of the other Washington seismic stations on the web recorded it. I am wondering what it might be? My recording is at http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/ 060530.165536.ebgz.psn Hi Roger, If you look carefuly at the trace, there is hf noise for maybe 15 sec before the main signal, which itself lasts for maybe 40 sec. If it had been a meteor, I would have expected an impulse signal without any initial buildup and with little tail. This looks more like a large aircraft to me. Regards, Chris Chapman
In a message dated 31/05/2006, rsparks@.......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I and*=20 ELL SHZ UW : Ellensburg, WA* recorded an event, but none of the other=20 Washington seismic stations on the web recorded it. I am wondering what it= =20 might be?

My recording is at=20
http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/060530.1655= 36.ebgz.psn
Hi Roger,
 
    If you look carefuly at the trace, there is hf=20 noise for maybe 15 sec before the main signal, which itself lasts for maybe=20= 40=20 sec. If it had been a meteor, I would have expected an impulse signal withou= t=20 any initial buildup and with little tail. This looks more like a large aircr= aft=20 to me.
 
    Regards,
 
    Chris Chapman
Subject: Recording from unknown source--Solved From: Roger Sparks rsparks@.......... Date: Wed, 31 May 2006 06:29:48 -0700 Hi All, Thanks for the comments. It turns out that it was a local quake, originating about 7.5 km from this station. Magnitude 2.0, 21.1 km deep. I posted about 6 hours after the quake. It took longer for the UW seismologist to post the quake on their website found at http://spike.geophys.washington.edu/recenteqs/Quakes/uw05301656.html Roger | Message 3 | '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' Subject: Recording from unknown source From: Roger Sparks Date: Tue, 30 May 2006 17:28:11 -0700 Hello All, I and* ELL SHZ UW : Ellensburg, WA* recorded an event, but none of the other Washington seismic stations on the web recorded it. I am wondering what it might be? My recording is at http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/060530.165536.ebgz.psn The UW recording is at http://www.pnsn.org/WEBICORDER/PNSN/ELL_SHZ_UW.2006053012.html I do not know exactly where *ELL SHZ UW : Ellensburg, WA* is located but I believe it is 5 or more miles away. I wonder if it might be a meteor? Roger __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 31 May 2006 21:27:08 +0000 Hi all I have changed about cable in order to block out electronic noise. I did use screened cat-5 cable. I did change about the cable from the geophone to the amplifer board. So far, this looks ok. But I did discover other type of noise that I pick up on my geophone, but that is the intal signal that GSM (Cell phone) brodcasts when they start calling out or start resiveing a call. Where I live, the GSM network uses 900Mhz freq. band. I don't think I can block that type of noise out from my recordings. But I problay can minimise the GSM noise, I hope. Regards -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sat, 03 Jun 2006 21:07:07 +0000 Hi all The spike problem still exist. :( I am out of ideas what this might be. Also, after I did change to screened cable I have been seeing alot of smaller spikes with regular intervals, those smaller spikes happen with 10 to 20 seconds spaces between them. That might becose of the computer (serial port issue), but I am not sure. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ian ian@........... Date: Sat, 03 Jun 2006 23:22:25 +0100 Hi, you could try to isolate where the spikes are entering into your system. 1: You could disconnect your geophone and short the input to your amplifier/filter. Run it for a few hours to see if the spikes go away and if they do then it's the cable between the geophone and the amp/filter. 2: If you still have spikes, then disconnect your cable to the A/D, short the input there and run it for a while. Your filter should eliminate spikes so it may be after the filter but best to do it systematically. Once isolated you may be able to narrow further on what the problem is. Cheers Ian Jón Frímann wrote: >Hi all > >The spike problem still exist. :( >I am out of ideas what this might be. Also, after I did change to >screened cable I have been seeing alot of smaller spikes with regular >intervals, those smaller spikes happen with 10 to 20 seconds spaces >between them. That might becose of the computer (serial port issue), but >I am not sure. > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: Larry Cochrane lcochrane@.............. Date: Sat, 03 Jun 2006 17:57:14 -0700 Hi Jón, Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter board? Regards, Larry Cochrane Redwood City, PSN Jón Frímann wrote: > Hi all > > The spike problem still exist. :( > I am out of ideas what this might be. Also, after I did change to > screened cable I have been seeing alot of smaller spikes with regular > intervals, those smaller spikes happen with 10 to 20 seconds spaces > between them. That might becose of the computer (serial port issue), but > I am not sure. > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: "Timothy Carpenter" geodynamics@....... Date: Sat, 3 Jun 2006 22:16:56 -0400 Larry and J=F3n, I think Larry may have focused on the root of the problem -- that is, gounding. In looking at your seismic traces, J=F3n, I see occasional = signals where there is an initial spike that is accompanied by a slow decay over = a period of a minute or more. This looks suspiciously like a leaking capacitor. In a recent case, geophones were emplaced by others using shielded cables on the order of 500-feet in length, the output was = terrible. After much troubleshooting and questioning of the folks who installed = the system, I found out that they had never brought the shield to ground. = One of the characteristics of their output was the same spike and subsequent = decay over time. It appears that the ungrounded shield was building up a = charge (especially during thunderstorms) that would slowly bleed off over time. Regards, -Tim- Timothy Carpenter GeoDynamics Consultants, Inc. Commerce Township, Michigan 48382 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of Larry Cochrane Sent: Saturday, June 03, 2006 8:57 PM To: psn-l@.............. Subject: Re: spike problem Hi J=F3n, Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter=20 board? Regards, Larry Cochrane Redwood City, PSN J=F3n Fr=EDmann wrote: > Hi all >=20 > The spike problem still exist. :( > I am out of ideas what this might be. Also, after I did change to > screened cable I have been seeing alot of smaller spikes with regular > intervals, those smaller spikes happen with 10 to 20 seconds spaces > between them. That might becose of the computer (serial port issue), = but > I am not sure. >=20 > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 03:09:05 +0000 Hi > Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter > board? The two colored wire is connected to the amp board properly, the same goes for the single colored one. This happens also with a cat-5 cable that is not screened, I was using that before I got screened cable. The sheld it self is not connected to anything, since I can't connect it to the ground, at least I don't know how to connect it to the ground. Since I don't see any connection for it. I know that the problem is not in the amp board. There are capacitors inside the geophone, I think that thease are capacitors. I can ground the shield of the cat-5 cable. If I get some instructions on how to do it. I can also replace the capacitors if I know what to buy and how to replace them. I know about good electronic store in Iceland that sells this type of items. This spike problem has been getting worse since I got the geophone, it was not there in the early start. In the past 2 months it has been getting really bad. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: "Steve Hammond" shammon1@............. Date: Sat, 3 Jun 2006 20:33:38 -0700 Do you have a cordless (radio) telephone? I had one that created the same sort of spikes when the phone rang. Steve Hammond PSN Aptos, CA -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of Jón Frímann Sent: Saturday, June 03, 2006 2:07 PM To: psn-l@.............. Subject: Re: spike problem Hi all The spike problem still exist. :( I am out of ideas what this might be. Also, after I did change to screened cable I have been seeing alot of smaller spikes with regular intervals, those smaller spikes happen with 10 to 20 seconds spaces between them. That might becose of the computer (serial port issue), but I am not sure. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 03:42:11 +0000 Hi Steve Yes, I have cordless telephone. But thease spikes happen even if the phone is not ringing at all. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ian ian@........... Date: Sun, 04 Jun 2006 09:06:32 +0100 Hi, If I understand this properly, it sounds like you do not have the outer braid / shield of your cable connected at either end. If so, then it should be but only at one end, the amplifier. Having said that, since the cable goes outside, you should consider using a lighning arrestor at the amp end, just in case you get a hit. Hope that helps. Ian Jón Frímann wrote: >Hi > > > >>Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter >>board? >> >> > >The two colored wire is connected to the amp board properly, the same >goes for the single colored one. This happens also with a cat-5 cable >that is not screened, I was using that before I got screened cable. The >sheld it self is not connected to anything, since I can't connect it to >the ground, at least I don't know how to connect it to the ground. Since >I don't see any connection for it. I know that the problem is not in the >amp board. There are capacitors inside the geophone, I think that thease >are capacitors. I can ground the shield of the cat-5 cable. If I get >some instructions on how to do it. I can also replace the capacitors if >I know what to buy and how to replace them. I know about good electronic >store in Iceland that sells this type of items. > >This spike problem has been getting worse since I got the geophone, it >was not there in the early start. In the past 2 months it has been >getting really bad. > >Regards. > > Hi,

If I understand this properly, it sounds like you do not have the outer braid / shield of your cable connected at either end.  If so, then it should be but only at one end, the amplifier.  Having said that, since the cable goes outside, you should consider using a lighning arrestor at the amp end, just in case you get a hit.

Hope that helps.

Ian

Jón Frímann wrote: 
Hi

  
Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter 
board?
    

The two colored wire is connected to the amp board properly, the same
goes for the single colored one. This happens also with a cat-5 cable
that is not screened, I was using that before I got screened cable. The
sheld it self is not connected to anything, since I can't connect it to
the ground, at least I don't know how to connect it to the ground. Since
I don't see any connection for it. I know that the problem is not in the
amp board. There are capacitors inside the geophone, I think that thease
are capacitors. I can ground the shield of the cat-5 cable. If I get
some instructions on how to do it. I can also replace the capacitors if
I know what to buy and how to replace them. I know about good electronic
store in Iceland that sells this type of items.

This spike problem has been getting worse since I got the geophone, it
was not there in the early start. In the past 2 months it has been
getting really bad.

Regards.
Subject: Re: spike problem From: "Geoffrey" gmvoeth@........... Date: Sun, 4 Jun 2006 05:56:30 -0700 When I was programming my own seismic receiver using the serial Com1 port on a typical PC I ran into a problem relating to timing and control of the serial communications that caused similar symptoms. The way I beat it was a long time ago and I never recorded it so I cant tell you what I did to beat it. I think I had to run the program under DOS only and not windows to solve the problem but I am not sure about that. It is so very important to write a proper error checking for any program using the serial ports or you get these funny glitches because something wrong has happened in the conversion or transfer of data resulting in an erroneous data giving you those glitches. That is everything I know about what those glitches might be. In my program I just check for any errors at all and count them so that I know if that is the problem if I get any glitches in my data. It is very difficult to include a proper error checking program. I think Windows is a time sharing thing and that will alone mess up the timing and control of asynchronous serial communications. Not certain about any of this but I no longer get these glitches or errors running under DOS in Windows 95. Sincerely; gmvoeth ----- Original Message ----- From: "Jón Frímann" To: Sent: Saturday, June 03, 2006 8:42 PM Subject: RE: spike problem > Hi Steve > > Yes, I have cordless telephone. But thease spikes happen even if the > phone is not ringing at all. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > 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: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 16:46:25 +0000 Hi I have connected the shield in the cable to the ground. Trugh a heating oven (or how it is spelled / word over it) in the room, it uses hot water so it is ideal for this type of connection to the ground. That is going to elimiate the shield problem chargeing up, at least it I hope it does. The connection to the ground is farly good. There is paint on the heating oven, but I don't think that is a problem. Now I only have to fix the larger spikes. Or replace the capacitor that is possible leaking, this spikes happens on all the channels, so I am problay going to have to replace them all. If that can be done. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 12:50:11 EDT In a message dated 03/06/2006, jonfr500@......... writes: The spike problem still exist Hi Jon, What length of cable in m are you using to connect the geophones to the amplifier board? Does the cat5 cable have a single bare wire inside the aluminised screen? It should have four tightly twisted pairs of insulated wires. Regards, Chris Chapman
In a message dated 03/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>The=20 spike problem still exist
Hi Jon,
 
    What length of cable in m are you using to conn= ect=20 the geophones to the amplifier board?
 
    Does the cat5 cable have a single bare wire ins= ide=20 the aluminised screen? It should have four tightly twisted pairs of insulate= d=20 wires.
 
    Regards,
 
    Chris Chapman
Subject: Re: spike problem From: John Popelish jpopelish@........ Date: Sun, 04 Jun 2006 13:02:56 -0400 J=F3n Fr=EDmann wrote: > Hi >=20 > I have connected the shield in the cable to the ground. Trugh a heating= > oven (or how it is spelled / word over it) in the room, it uses hot > water so it is ideal for this type of connection to the ground. That is= > going to elimiate the shield problem chargeing up, at least it I hope i= t > does. The connection to the ground is farly good. There is paint on the= > heating oven, but I don't think that is a problem. >=20 > Now I only have to fix the larger spikes. Or replace the capacitor that= > is possible leaking, this spikes happens on all the channels, so I am > problay going to have to replace them all. If that can be done. >=20 > Regards.=20 The important aspect of the cable ground is not that it actually be a=20 good Earth connection, but that it be the potential that the high gain=20 amplifier considers to be the zero volt reference. If you tie the=20 cable shield to some actual Earth connection, you also need to tie the=20 amplifier zero volt reference to that same potential. This difficulty in doing this may be that it is already grounded at=20 some other point (say, through the computer power plug), so that=20 adding this second ground contact will produce what is called a ground=20 loop. The dual ground connection will try to equalize the=20 instantaneous potential at the two ground points by passing large=20 currents along the conductor that connects them. This current will=20 inject (by transformer coupling) noise into the signal lines that=20 parallel the line that connects the two grounds. This is why low noise systems are usually made with a very=20 specifically single point grounded system. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 13:00:46 EDT In a message dated 04/06/2006, jonfr500@......... writes: I have connected the shield in the cable to the ground. Through a heating oven in the room, it uses hot water so it is ideal for this type of connection to the ground. That is going to eliminate the shield problem charging up, at least it I hope it does. The connection to the ground is fairly good. There is paint on the heating oven, but I don't think that is a problem. Now I only have to fix the larger spikes. Or replace the capacitor that is possible leaking, this spikes happens on all the channels, so I am probably going to have to replace them all. If that can be done. Hi John, Does your cold water supply or the hot water supply use copper / metal pipes? Look at the electric meter / fuse board/ trip board. There should be a thick green earth connection wire. Don't despair! Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have=20 connected the shield in the cable to the ground. Through a heating oven in= the=20 room, it uses hot water so it is ideal for this type of connection to the=20 ground. That is going to eliminate the shield problem charging up, at leas= t it=20 I hope it does. The connection to the ground is fairly good. There is pain= t on=20 the heating oven, but I don't think that is a problem.

Now I only h= ave=20 to fix the larger spikes. Or replace the capacitor that
is possible=20 leaking, this spikes happens on all the channels, so I am
probably goin= g to=20 have to replace them all. If that can be done.
Hi John,
 
    Does your cold water supply or the hot water su= pply=20 use copper / metal pipes?
    Look at the electric meter / fuse board/ trip=20 board. There should be a thick green earth connection wire.
    Don't despair!
 
    Regards,
 
    Chris Chapman
Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:12:39 +0000 Hi It has two componment inside the cable, the shield has wires and it also is silver type skin over the actual cat-5 wires. > What length of cable in m are you using to connect the geophones to > the amplifier board? I use 15 meters. It is the minmal lenght I can use. > This difficulty in doing this may be that it is already grounded at > some other point (say, through the computer power plug), so that > adding this second ground contact will produce what is called a > ground > loop. I hope that doesn't happen. The shield is not connected to the amp board it self or to the geophone. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:16:57 +0000 Hi Chris. It's hot water. This is used to heat up my apartment. They use metal pipes, the whole system is ground connected at entry point inside the block. > Look at the electric meter / fuse board/ trip board. There should be a > thick green earth connection wire. I am unsure what you mean here. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 13:28:30 EDT In a message dated 04/06/2006, jonfr500@......... writes: It's hot water. This is used to heat up my apartment. They use metal pipes, the whole system is ground connected at entry point inside the block. Hi Jon, Do you also have a metal pipe cold water supply? Or is it plastic? > Look at the electric meter / fuse board/ trip board. There should be a > thick green earth connection wire. I am unsure what you mean here. I presume that you pay for your electricity? There will be thick power cables entering your flat and there will be a main power fuse, a meter for recording how much electricity you use and a fuse box / board or circuit trip board with switches. Connected to this should be a thick earth wire, usually yellow and green or plain green. Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>It's hot=20 water. This is used to heat up my apartment. They use metal
pipes, the=20 whole system is ground connected at entry point inside=20 the
block.
Hi Jon,
 
    Do you also have a metal pipe cold water supply= ? Or=20 is it plastic?
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>=20 Look at the electric meter / fuse board/ trip board. There should be a
= >=20 thick green earth connection wire.

I am unsure what you mean=20 here.
    I presume that you pay for your electricity? Th= ere=20 will be thick power cables entering your flat and there will be a main power= =20 fuse, a meter for recording how much electricity you use and a fuse=20 box / board or circuit trip board with switches. Connected to= =20 this should be a thick earth wire, usually yellow and green or plain=20 green.  
 
    Regards,
 
    Chris Chapman
Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:36:52 +0000 Hi Chris Everything is connected to ground, it is by some regulation why that is done. I can't see the wire you descripe, it is hidden in the setup. The ground plug is in every electronic plug that is in my apartment. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:58:12 +0000 Hi The spikes continue. The only thing that has changed is that the smaller spikes appears to be gone. When the spike appars, the line appears to shift a little, not a alot, but a large enugh so that I can see it. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: John Popelish jpopelish@........ Date: Sun, 04 Jun 2006 14:13:43 -0400 J=F3n Fr=EDmann wrote: (snip) >>This difficulty in doing this may be that it is already grounded at=20 >>some other point (say, through the computer power plug), so that=20 >>adding this second ground contact will produce what is called a >>ground=20 >>loop. >=20 > I hope that doesn't happen. The shield is not connected to the amp boar= d > it self or to the geophone. But that means that the cable shield (that is intended to keep any=20 external electric fields from driving capacitive current signals into=20 any of the shielded conductors) is not necessarily grounded to a=20 potential that the amplifiers consider to be zero volts. The=20 instantaneous potential to one point on the Earth can be quite=20 different than the potential at some other point, since atmospheric,=20 subterranean and the electrical power system dump current into various=20 points on the Earth at any particular moment, and those currents drop=20 voltage as they spread out in the Earth. The only way a cable shield keeps external signals out of the shielded=20 conductors is if the shield is held at whatever potential the=20 receiving electronics considers to be zero volts. You need to find=20 the signal common (zero volts as far as the electronics sees the=20 universe) and tie the shield to that. If the geophone has a shield=20 connection, it also should be tied to that potential through the cable=20 shield, or a spare conductor running through that shield. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 14:10:37 EDT In a message dated 04/06/2006, jonfr500@......... writes: Everything is connected to ground, it is by some regulation why that is done. I can't see the wire you descripe, it is hidden in the setup. The ground plug is in every electronic plug that is in my apartment. Hi Jon, That it usual. Do you have power fuses that can be replaced, or do you have a row of switches for the various circuits? Is your cold water supply in metal of plastic pipes? Look under the handbasin in the bathroom? It has two componment inside the cable, the shield has wires and it also is silver type skin over the actual cat-5 wires. Make a connection from the shield wires in the cabler to the 0 V rail on your amplifier board. It does not matter which of the three. This should greatly reduce the spike problems. I did suggest that you use six core cable with a plaited copper screen. This cable has six plastic insulated colour coded wires, a plaited bare copper screen and a PVC sheath. Could you not buy any? It is likely to be much better that cat5 cable. Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>Everything is connected to ground, it is by some regulation why t= hat=20 is
done. I can't see the wire you descripe, it is hidden in the setup.=20 The
ground plug is in every electronic plug that is in my=20 apartment.
Hi Jon,
 
    That it usual. Do you have power fuses that can= be=20 replaced, or do you have a row of switches for the various circuits?
 
    Is your cold water supply in metal of plastic=20 pipes? Look under the handbasin in the bathroom?
 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>It has=20 two componment inside the cable, the shield has wires and it also
is si= lver=20 type skin over the actual cat-5 wires.
    Make a connection from the shield wires in the=20 cabler to the 0 V rail on your amplifier board. It does not matter which of=20= the=20 three.
    This should greatly reduce the spike problems.=20
 
    I did suggest that you use six core cable with=20= a=20 plaited copper screen. This cable has six plastic insulated colour code= d=20 wires, a plaited bare copper screen and a PVC sheath. Could you not buy any?= It=20 is likely to be much better that cat5 cable.
 
    Regards,
 
    Chris Chapman
Subject: Re: spike problem From: Larry Cochrane lcochrane@.............. Date: Sun, 04 Jun 2006 12:46:10 -0700 Hi Jón, The electronic parts inside the sensor are resistors used for damping. They are not capacitors. The resistors should not be removed. Regards, Larry Cochrane Redwood City, PSN Jón Frímann wrote: > Hi > >> Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter >> board? > > The two colored wire is connected to the amp board properly, the same > goes for the single colored one. This happens also with a cat-5 cable > that is not screened, I was using that before I got screened cable. The > sheld it self is not connected to anything, since I can't connect it to > the ground, at least I don't know how to connect it to the ground. Since > I don't see any connection for it. I know that the problem is not in the > amp board. There are capacitors inside the geophone, I think that thease > are capacitors. I can ground the shield of the cat-5 cable. If I get > some instructions on how to do it. I can also replace the capacitors if > I know what to buy and how to replace them. I know about good electronic > store in Iceland that sells this type of items. > > This spike problem has been getting worse since I got the geophone, it > was not there in the early start. In the past 2 months it has been > getting really bad. > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 18:43:56 EDT In a message dated 04/06/2006, jonfr500@......... writes: Yes, I have cordless telephone. But thease spikes happen even if the phone is not ringing at all. Hi Jon, Is the main phone distribution aerial any where near you? Thie could be calling a lot of other pnones in the area. Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Yes, I=20 have cordless telephone. But thease spikes happen even if the
phone is=20= not=20 ringing at all.
Hi Jon,
 
    Is the main phone distribution aerial any w= here=20 near you? Thie could be calling a lot of other pnones in the area.
    
    Regards,
 
    Chris Chapman
 
Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 05 Jun 2006 00:06:57 +0000 Hi I live in a block with seven other apartment in them, at least two of those apartments are close enugh so wireless signal can reach my apartment. There is one GSM transmitter near me, in about 400 meters away from my location in direct line. It uses 900Mhz band. > Is your cold water supply in metal of plastic pipes? Look under the > handbasin in the bathroom? The cold water uses metal pipes. This goes for the whole apartment, same as the hot water pipes. The spikes have frequancy down to 0.1Hz, they appear at every frequancy band. But sometimes they drop in strength as I got lower in the frequancy. > I did suggest that you use six core cable with a plaited copper > screen. This cable has six plastic insulated colour coded wires, a > plaited bare copper screen and a PVC sheath. Could you not buy any? It > is likely to be much better that cat5 cable. I don't think this was avalable from where i did buy the Cat-5 cable. I told the guy what I needed, he did suggest cat-5 cable. But if I get a picture of what you mean, I can check if I can buy that type of cable. Far as I can tell, this problem is not in the amplifer board and not in the geophone it self. I don't have a second testing unit (geophone), so that is just a guess. Is it possible that some electronic device in my apartment might be failing and creating this type of noise ? I have three computers and I'm going to replace at least one PSU next week becose I know it is getting old an overused. There also must be some way for me to filter the signal out. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: "Randy Kimball" randy.kimball@........... Date: Sun, 04 Jun 2006 22:09:02 -0500 Do you have a cell phone.... now hang on... Cell phones check in with the tower systems every so often. This is how they know if your phone is on line and to which tower to transmit to your cell phone. I'm no cell phone expert so my version of this is perhaps off just a little but I think this is the layman's version of what happens. If your cell is on and in the area of .... well you get the rest... this is the daut daut daut..daut sound we hear in our car radios at times when the cell phone is near the radio receiver. In my coach I hear it in my CB, too. Could this be the mystery everyone is seeking? -randy- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: John Popelish jpopelish@........ Date: Sun, 04 Jun 2006 23:53:39 -0400 Randy Kimball wrote: > Do you have a cell phone.... now hang on... > Cell phones check in with the tower systems every so often. This is how > they know if your phone is on line and to which tower to transmit to your > cell phone. I'm no cell phone expert so my version of this is perhaps off > just a little but I think this is the layman's version of what happens. If > your cell is on and in the area of .... well you get the rest... this is the > daut daut daut..daut sound we hear in our car radios at times when the cell > phone is near the radio receiver. In my coach I hear it in my CB, too. > > Could this be the mystery everyone is seeking? Could be, but I am suspecting a heater switching on and off, every few seconds. Printer fuser roll heater comes to mind. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: "Timothy Carpenter" geodynamics@....... Date: Mon, 5 Jun 2006 01:52:42 -0400 J=F3n, You should NOT be connecting the shield to the water pipe -- it should = be connected to ground on the amplifier board. Consult the specifications / user manual for the amplifier board to see where you should make the connection -- I'd suspect that the connection should be made to the = board's "power ground". Do you have the geophones connected single-ended or double-ended (full differential). If your board has the capability, I'd recommend that your connections be full differential. When I mentioned that some of your signals had the appearance of a capacitive discharge, I didn't mean to imply that you had capacitors in = your geophones. If there is anything in the geophone housing that looks like = a capacitor, my bet is that it's a damping resistor. Such resistors are installed to reduce the resonance of the geophone when signals come in = at or near its natural frequency. You can see the effects of different = resistors on the geophone response at: http://seismicnet.com/geophone/l15bspec.gif On the chart, response A is for the case with no resistor installed. = Cases B through D are for successively higher resistances. If I was using this = type of geophone for monitoring earthquake activity, I'd remove the resistors = -- just to gain that bit of additional sensitivity throughout the = bandwidth. Regards, -Tim- Timothy Carpenter 5043 Whitlow Court Commerce Township, Michigan 48382 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of J=F3n Fr=EDmann Sent: Sunday, June 04, 2006 12:46 PM To: psn-l@.............. Subject: Re: spike problem Hi I have connected the shield in the cable to the ground. Trugh a heating oven (or how it is spelled / word over it) in the room, it uses hot water so it is ideal for this type of connection to the ground. That is going to elimiate the shield problem chargeing up, at least it I hope it does. The connection to the ground is farly good. There is paint on the heating oven, but I don't think that is a problem. Now I only have to fix the larger spikes. Or replace the capacitor that is possible leaking, this spikes happens on all the channels, so I am problay going to have to replace them all. If that can be done. Regards.=20 --=20 J=F3n Fr=EDmann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: "Timothy Carpenter" geodynamics@....... Date: Mon, 5 Jun 2006 02:04:10 -0400 Larry, I just noted your comment about not removing the damping resistors. Why = not run without the shunt resistors? You'd loose the so-called flat response near the natural frequency -- but so what? You'd gain additional sensitivity.=20 -Tim- Timothy Carpenter 5043 Whitlow Court Commerce Township, Michigan 48382 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of Larry Cochrane Sent: Sunday, June 04, 2006 3:46 PM To: psn-l@.............. Subject: Re: spike problem Hi J=F3n, The electronic parts inside the sensor are resistors used for damping. = They are not=20 capacitors. The resistors should not be removed. Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: Larry Cochrane lcochrane@.............. Date: Mon, 05 Jun 2006 01:13:54 -0700 Tim, Jón is not having gain problems and having a flat response is more important then the small loss in output do to the damping resistors, IMHO. -Larry Timothy Carpenter wrote: > Larry, > I just noted your comment about not removing the damping resistors. Why not > run without the shunt resistors? You'd loose the so-called flat response > near the natural frequency -- but so what? You'd gain additional > sensitivity. > -Tim- > > Timothy Carpenter > 5043 Whitlow Court > Commerce Township, Michigan 48382 > > -----Original Message----- > From: psn-l-request@.............. [mailto:psn-l-request@............... On > Behalf Of Larry Cochrane > Sent: Sunday, June 04, 2006 3:46 PM > To: psn-l@.............. > Subject: Re: spike problem > > Hi Jón, > > The electronic parts inside the sensor are resistors used for damping. They > are not > capacitors. The resistors should not be removed. > > Regards, > Larry Cochrane > Redwood City, PSN > > > __________________________________________________________ > > 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: spike problem From: Roger Sparks rsparks@.......... Date: Mon, 05 Jun 2006 06:17:53 -0700 Hi Jon, Have you posted two or three recordings of the spikes? It should be helpful to examine the spikes for duration and shape. From what I see by looking at your webcorders, the magnitude varies widely. The time between spikes seems not to have a pattern. Further, the spikes do not seem to have a night or daylight pattern. Also from what I see on your webcorders, all three channels seem to spike at the same time, but the magnitudes seem to be slightly different. That pattern would dictate some common feature shared by all channels. It would rule out problems which originated within any single channel such as the channel amplifier board. Best wishes, Roger ----- Original Message ----- From: "Jón Frímann" To: Sent: Saturday, June 03, 2006 8:42 PM Subject: RE: spike problem > > Hi Steve > > > > Yes, I have cordless telephone. But thease spikes happen even if the > > phone is not ringing at all. > > > > Regards. > > -- > > Jón Frímann __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 05 Jun 2006 18:19:45 +0000 Hi > Have you posted two or three recordings of the spikes? I am doing that just now. Thanks for the reminder. Here is a recording of the spike that did happen last night. This is the larger type of spikes. http://www.simnet.is/jonfr500/earthquake/winquake/spike.hvt1z.gif Here is a recording of the smaller spikes that happen after I did connect the cat-5 cable directly to the geophone. http://www.simnet.is/jonfr500/earthquake/winquake/smaller.spikes.hvt1z.psn.gif Timothy Carpenter wrote: > Do you have the geophones connected single-ended or double-ended (full > differential). If your board has the capability, I'd recommend that > your > connections be full differential. I connect both wires. John Popelish wrote: > Could be, but I am suspecting a heater switching on and off, every > few > seconds. Printer fuser roll heater comes to mind. I only own a ink printer. Randy Kimball wrote: > Do you have a cell phone.... now hang on... > Cell phones check in with the tower systems every so often. This is > how > they know if your phone is on line and to which tower to transmit to > your > cell phone. I'm no cell phone expert so my version of this is perhaps > off > just a little but I think this is the layman's version of what > happens. If > your cell is on and in the area of .... well you get the rest... this > is the > daut daut daut..daut sound we hear in our car radios at times when the > cell > phone is near the radio receiver. In my coach I hear it in my CB, > too. > > Could this be the mystery everyone is seeking? I own a GSM phone (cell phone), I know that it can pickup noise from it if I am close to the line or to the ampilfer board. But that is not all the time, I can also see a diffrance from that type of noise and what I am dealing with now. My gsm phone is usally on the board on my main desktop computer, that is a good meter away from the amplifer board and the wire that is connected to the geophone. I know now that there is a noise in the MW radio band (Chris did ask me to check on that). That noise comes from the computers that I own. I can't change my setup becose I live in a limited space. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 05 Jun 2006 20:16:52 +0000 Hi Is it possibe that this spike problems is becose of the cable that I am using ? I am considering buying rc type cable (stero type) type of cable in order to test this proberly. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ian ian@........... Date: Mon, 05 Jun 2006 21:31:55 +0100 HI, I don't know if it's your cable or not but I use satellite dish coax cable. Cheap and waterproof. Cheers Ian Jón Frímann wrote: >Hi > >Is it possibe that this spike problems is becose of the cable that I am >using ? > >I am considering buying rc type cable (stero type) type of cable in >order to test this proberly. > >Regards. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: "Timothy Carpenter" geodynamics@....... Date: Mon, 5 Jun 2006 16:43:46 -0400 J=F3n, Probably not. If the cable was bad then it is unlikely that you'd get = such a close match for the three channels. Have you attached the cable shield to the acquisition board's ground? It must be grounded at the board (not on a water pipe). I'm presuming that you have a six-conductor cable with a foil shield and = a shield ground wire. That would look like this: /--\shield shield /--\ Geophone 1 + ---/----\------- ---/----\------- Board Ch1 + Geophone 1 - ---|-----|------ ---|-----|------ Board Ch1 - | | | | Geophone 2 + ---|-----|------- ---|-----|------- Board Ch2 + Geophone 2 - ---|-----|------- ---|-----|------- Board Ch2 - | | | | Geophone 3 + ---|-----|------ ---|-----|------ Board Ch3 + Geophone 3 - ---\----/------- ---\----/------- Board Ch3 -=20 unconnected---\--/ \--/---Shield wire--- Board = Ground shield wire -Tim- Timothy Carpenter 5043 Whitlow Court Commerce Township, Michigan 48382 geodynamics@....... (secondary) -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of J=F3n Fr=EDmann Sent: Monday, June 05, 2006 4:17 PM To: psn-l@.............. Subject: Re: spike problem Hi Is it possibe that this spike problems is becose of the cable that I am using ? I am considering buying rc type cable (stero type) type of cable in order to test this proberly. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 05 Jun 2006 21:12:16 +0000 Hi Maybe not bad cable, but more like some noise that the cable picks up from the envroment. The smaller spikes problem still exists, even after my attemts to fix it. Thease smaller spikes might be comeing from a natrual source. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: John or Jan Lahr JohnJan@........ Date: Mon, 05 Jun 2006 14:16:12 -0700 Have you tried just attaching resistors to the amplifier, in place of the cable and geophone? If there are still spikes, then the cable is not involved. Have you tried a short cable between the geophone and the amplifier? Don't worry about the local ground noise, just look for the spikes. The length of the cable may be a critical factor, but not necessarily. If there are spikes with a short cable but not with just resistors, then you can experiment with the ground attachments and cable type with short cables until you find something that works. John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 05 Jun 2006 21:38:18 +0000 Hi I don't own a short cable for this, with stereo connections at the end. I can buy some tomorrow and test it then. The smaller spikes aren't constant. But there is a pattern in them. So I think it is some type of noise that the cable picks up or some type of noise that the geophone picks up. > Have you tried just attaching resistors to the amplifier I am unsure what you mean here. If I disconnect the cable from the amplifer board, the plot is flat. No spikes, large or small ones. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 05 Jun 2006 22:31:15 +0000 Hi Is it possible that this spikes might come becose of a sensor failure ? The smaller spikes didn't start until I did connect the cat-5 cable directly to the geophone sensors. They still are there, even if I have reconnected the orginal wires. Just a thought. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: "Timothy Carpenter" geodynamics@....... Date: Mon, 5 Jun 2006 18:59:55 -0400 J=F3n, There is some type of very high frequency signal entering the system. = This has nothing to do with the geophones. They appear to be functioning adequately because all three channels are responding to discreet events. Have you connected the shield wire to the ground connection on the board yet? If you have, and you still are getting the spikes, then the next step is = to do as others have suggested -- disconnect the cables from the board and place a (approx 330 ohm) resistor across the + & - terminals for each of = the channels. Run the board for a few minutes -- there should be a flat = response with no spikes. If you do get spikes then a RF signal is getting into = the board and/or computer. If there are no spikes after several minutes of operation, then = disconnect the wires at the geophone case and use the same resistors to shunt the = ends of the cables. If no spikes occur then the problem is probably in the = wiring going to the transducers -- check the soldered connections. (All of your connections are soldered aren't they? If not, then do so.) I've had over 300 meters of cable strung out between geophones and my = ADC system along a 600-volt light rail train track -- and had no problems = with spikes entering the system -- even during thunderstorms. -Tim- Timothy Carpenter 5043 Whitlow Court Commerce Township, Michigan 48382 geodynamics@....... (secondary) -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of J=F3n Fr=EDmann Sent: Monday, June 05, 2006 6:31 PM To: psn-l@.............. Subject: RE: spike problem Hi Is it possible that this spikes might come becose of a sensor failure ? The smaller spikes didn't start until I did connect the cat-5 cable directly to the geophone sensors. They still are there, even if I have reconnected the orginal wires. Just a thought. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Mon, 05 Jun 2006 23:45:36 +0000 Hi > Have you connected the shield wire to the ground connection on the board yet? No. I don't know where it is on the board. I've been trying to look for it, but not found it. I am going to have to buy a 330 ohm resistor. I know that if i disconnect the geophone cable from the amplifer board. I get flat line and no spikes at all. > (All of your > connections are soldered aren't they? If not, then do so.) Connection inside the geophone are soldered properly. I have terminal block screws on the amplifer board. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: Mark Robinson mark.robinson@............... Date: Tue, 06 Jun 2006 13:12:18 +1200 Jón Frímann wrote: > Hi > >> Have you connected the shield wire to the ground connection on the > board > yet? > > No. I don't know where it is on the board. I've been trying to look for > it, but not found it. As Larry said, it should be connected to the 0 Volt terminal for the power supply. If the geophone has a metal body then that should be connected to the shield wire too. It may be best to then electrically insulate the geophone body from true ground. Can you draw an electrical diagram of what you have installed ? Is there anything near the sensor that could generate a magnetic pulse ? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Mon, 5 Jun 2006 21:18:09 EDT In a message dated 06/06/2006, jonfr500@......... writes: > Have you connected the shield wire to the ground connection on the board yet? No. I don't know where it is on the board. I've been trying to look for it, but not found it. Hi Jon, Do you have the _http://psn.quake.net/serialamp.html_ (http://psn.quake.net/serialamp.html) or the _http://psn.quake.net/eqamp.html_ (http://psn.quake.net/eqamp.html) amplifier board? I am going to have to buy a 330 ohm resistor. I know that if I disconnect the geophone cable from the amplifer board. I get flat line and no spikes at all. Great news! Then you don't need to buy any 330 ohm resistors! You are seeing pickup on the cable. > (All of your connections are soldered aren't they? If not, then do so.) Connection inside the geophone are soldered properly. I have terminal block screws on the amplifer board. ? Neither of Larry's boards usually have screw connectors? The boards usually have phono connectors. The outside ring with two solder connections is the 0V line. Look at the back of the amplifier board near the inputs. One input will have a short narrow track leading to pin 3 of the opamp and a 10 K Ohm resistor. The other twin 0V inputs will have a wide track across the board. Do you have an electric / electronic measuring meter? Regards, Chris Chapman
In a message dated 06/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>=20 Have you connected the shield wire to the ground connection on the board=20 yet?

No. I don't know where it is on the board. I've been trying to= =20 look for
it, but not found it.
Hi Jon,<