Hi Everyone,

Chris wrote:
> The low pass filter on your amplifier board should  be 10 Hz and have 8 
> poles. In practice, a signal at 13.4 Hz will be reduced to  1/10 and one at 18 
> Hz to 1/100.
>     The amplifier has a high pass filter set at 0.05 Hz  = 20 sec., which is 
> well below the lowest response of your geophones.

Actually Jon's Amp/Filter board has a 20 Hz 7 pole low pass filter. I usually set the 
filter to 20 Hz instead of the 10 Hz if I know that the filter board will be used 
with a geophone to record local events.

Regards,
Larry Cochrane
Redwood City, PSN

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)