Greg,

Nice to hear from you.  I picked up your site on a Google search for the=20
BB13.  I try to drop by each day to see the seismic activity at OCO.

I saw the recent Virginia event and I think I saw the big event in Algeria=
=20
although the times don't seem quite right.

It looks like a nice museum display you have set up there.  I might try to=
=20
drop by sometime.  I visit Missouri several times a year.

Thanks for the tips.  The last thing I need is a broken flexure.

I am thinking about using Larry's A/D.  Did you find the filters that=20
useful?  Do you run a lot of gain between the BB13 and the A/D?

Frank

At 01:15 PM 5/27/03 -0500, you wrote:

>Hello Frank,
>We currently have a BB-13 setup and running using Larry C's A-D board,=20
>filters, and WinSDR. It takes a bit of work to get the setup correct, and=
=20
>then to keep the mass centered. The BB-13 is very sensitive to thermal=20
>changes and will drift hundreds of mv. with just a few degrees of=20
>temperature change. Preferred mass centering is +/- 30 mv., and the only=20
>way to achieve this is putting the instrument in a thermally stable=20
>environment.
>
>Another thing to watch out for is not to turn the mass centering screw too=
=20
>far as the spring guide pin will come out of the guide, causing damage to=
=20
>the flexures.
>
>The BB-13 is capable of running in master or slave mode when there are=20
>multiple BB-13's (Z,E,N), but when running a single unit the jumpers must=
=20
>be set for master operation.
>
>To see some recent events recorded using the BB-13 (OCO2Z) checkout=20
>Larry's "Recent Events" page and look for the Omniplex OCO2Z sensor ID.=20
>http://www.seismicnet.com/cgi-=
dos/event.exe
>
>The BB-13 seismograph is in the shadow zone of the 7.0 Halmahera event=20
>yesterday but clearly recorded wave periods from 2 to 28 seconds.
>
>Greg Christenson
>NEIC station code OCO
>Omniplex Science Museum
>http://www.omniplex.org/OCOdata
>
>-----Original Message-----
>From: Frank Gentges K=D8BRA=20
>[mailto:fgentges@...............
>Sent: Monday, May 26, 2003 11:59 AM
>To: PSN-L@..............
>Subject: Teledyne Geotech BB13 Seismometer
>
>Hi,
>
>I have had an interest in setting up a seismograph for some time.  That
>interest was suddenly fired into full force when I happened upon a Teledyne
>Geotech BB13 broadband sensor on a hamfest swap table several weeks ago. I
>am now working on a seismograph setup in my spare time.
>
>...

Frank Gentges K=D8BRA

LF web site at 

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