hi guys

     Am still getting nowhere with this system  !!  :(

  Rebuilt the dampening system and it works well for the natural period of the
seismo.  That is, have the boom swinging naturally, ~ 7 sec period. Slide 
up the
dampening magnets to the aluminium vane and the natural osc stops within a
cycle.  That part looks ok

  The problem is when viewed on SDR there is an ongoing osc of ~ 10 Hz that
slowly dies off over another ~ 30 sec till the trace is basically 
flatlining. ( of course
you can't see the 10Hz osc visibly.
  With the dampening in place, the seismo is VERY responsive to hi freq (>1Hz)
noise and any of this noise, walking around the house near the 
seismo,  vehicular
traffic out on the road, etc etc just shows up as a large amplitude of this 
10Hz
osc that then dies off back to the flatline ( + - a small data count).

If I remove the sensor coil from the there is NO ~ 10 Hz osc visible, That 
sort of
indicates that its not some extraneous signal being picked up. But on the other
hand, I cant imagine how a supposed long period device is even able to osc at
~ 10 Hz ??

cheers
Dave


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