Hi Everyone,

After spending way too much time beating myself up trying to setup the WinSDR's filters, I want to ask the group for pointers.

My setup includes 3 axis Mark L15B 4.5Hz sensors, Larry's A/D & filter boards.

Where I'm at is in the suburbs of Santa Rosa California, with some local  street traffic a few hundred feet, and some nearby highway traffic  1/2 mile away.  (So I know it's not ideal.  But that's what I've got to work with.)

What I'm aiming for is local activity around 200 miles out. No teleseismic stuff yet. (I have an unused 4th channel on the board earmarked for this someday.)  I'm just about 25 miles south from the geothermal fields here in Northern California,  So there's just about always something to watch everyday. (Besides auto traffic!  If I can get this dialed in better.)

Specifically. How do folks have their low / hi pass filters set? (Specific freq & number of poles would be a REAL help.)  Just as a starting point.

Anything I missed in the setup I should be concerned with?

Any other questions about my setup please feel free to ask.


Thanks for the help in advance.


Dave Willey





Hi Everyone,

After spending way too much time beating myself up trying to setup the WinSDR's filters, I want to ask the group for pointers.

My setup includes 3 axis Mark L15B 4.5Hz sensors, Larry's A/D & filter boards.

Where I'm at is in the suburbs of Santa Rosa California, with some local  street traffic a few hundred feet, and some nearby highway traffic  1/2 mile away.  (So I know it's not ideal.  But that's what I've got to work with.)

What I'm aiming for is local activity around 200 miles out. No teleseismic stuff yet. (I have an unused 4th channel on the board earmarked for this someday.)  I'm just about 25 miles south from the geothermal fields here in Northern California,  So there's just about always something to watch everyday. (Besides auto traffic!  If I can get this dialed in better.)

Specifically. How do folks have their low / hi pass filters set? (Specific freq & number of poles