> From:    Dan 
> Date:    Fri, 16 Feb 2001 23:08:59 -0700
>
> I read somewhere (Nuts & Volts I think) that a decent sound card can be
> used for data acquisition.  Perhaps someone on the list with a lot more
> knowledge of these things could expand on this a bit more.
> Hmmm... bad idea.  Sound cards have a few properties that make them
 > good sound cards, but bad data acquisition cards.

There may be a problem with using sound card a/d for seismic data.
I found a note on the web that

> Sound cards have a few properties that make them
> good sound cards, but bad data acquisition cards.
>
 >   - input is generally heavily filtered, with unknown filters, but
 >     generally cut out anything below 20 Hz, around 50 or 60 Hz (depending
 >     on your local line frequency), and above 10 kHz.  The <20 Hz
 >     filter is nasty, since it makes DC measurements impossible.

If all you need is an a/d for your amplified and filtered data,
then you might consider the $99 DataQ 12 bit a/d box with serial IO:
http://www.dataq.com/cgi-local/SoftCart.exe/products/startkit/di151rs.htm?E+
scstore
Radio Shack carries it. Search for part #910-4932 at
http://www.radioshack.com

I believe that Alan Jones has recently modified his Amaseis freeware to
work with the DataQ:
http://www.geol.binghamton.edu/faculty/jones/as1.html

I am working on an inexpensive electronics board for seismic
amp/filter/adc/serialIO with an 8 pole bessel filter and 16 bit
adc that can process Lehman or geophone data.  If you want
to be a beta tester, I can sell you one for $99 that comes wired to
a 9k pickup coil, and needs no power supply since it gets
power from the PC serial port.  For Lehman processing I generally
set the LP to 1 Hz and the SPS to 8.  All you do is mount the coil
in your magnet field and plug the DB9 connector into your
PC serial port.  The output is compatible with Amaseis.

Hope this helps,

Dave

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