"gmv" wrote in message
news:J7MNd.24453$C24.9065@attbi_s52...

"Watson A.Name - "Watt Sun, the Dark Remover""
wrote in message ...

"gmv" wrote in message
news:jJdNd.21541$C24.9629@attbi_s52...
Interesting,
I always thought the opamp buffered the output
so you could hook it to anything between 2K
and infinity.
I will keep in mind what you have said.
I have noticed a terrible ringing effect at Q
5 and above.
Maybe that is what you are talking about.
In any case I really need to see things between .5Hz
and 2Hz. It is only the noise in my local area that
keeps me from doing this as far as I can tell.

http://home.mchsi.com/~gmvoeth/index.html

will show a bit more of what I am doing.

Buy the RS printed circuit board that has the same layout as the
breadoard. Build the circuit on that board, and put it inside of a
metal enclosure, so that most of the noise is kept out of the
circuit.

What is "RS printed circuit board " ?

RS = Radio Shack AKA Radio Scrap, etc. They sell a PC board that has
the same layout as the breadboard. Makes it easy to transfer the
circuit to a permanent circuit board.

I have settled on using only a single filter
as is now posted to my web site. This will
limit one to only seeing P waves but in
this noisy environment it is the best I can do.
I agree with everything you say except I can not
put a preamp outside with the Geophone.

Well, that's probably the reason why you are getting so much noise!

There is a circuit I have included not on the
schematic and it is a 567 tone decoder on the back
end to decode WWV calibration marks.

Thanks for your advice, I can see a lot of
common sense to it. But I still do not
know how to buy a circuit board that already
has my layout on it. I figure I will have
to do the layout and etching etc... myself.

I'm not sure you understand. The hole patterns match those on the
breadboard.
Here it is, it's catalog # 276-170 and costs a bit over $3.
http://www.radioshack.com/product.as...category%5Fnam
e=CTLG%5F011%5F002%5F002%5F000&product%5Fid=276%2D 170&MSCSProfile=745D84
CBF04D14A48AA6FF9C89D722C0BA68C1B04FE384678A5285FC D6E056B17AF21627FDABE3
16B90B3C038D68EBD6B7F9F3BD1712EAA9951ACB2590A05C65 17EFE46941FEFDD1985D4E
FD6321F5E70B4DE9B6C1D45512DCD9FB3DBCACB9479D26760F AF1D7B193B4FEA078B5E09
80BDD61634ABB7D328B012D36915420A2B457BE162481F674B


All preamplification should be done as close as possible to the
geophone, to get the signal well above the noise _before_ it goes
any
distance.

Filtering should be done at the other end, to get rid of noise in
the
long transmission line between the sensor and the PC.

One other important point. The outside can of the electrolytic is
at
signal level, and is a large capacitance to the outside world. Just
shielding these from outside noise should help. You might consider
putting some aluminum foil over the ones at the input, and grounding
the
foil to common. Just to see how much it will help to put the whole
thing in an enclosure.

[snip]