Hi Jon
   I agree with Chris. I record my quakes as raw data then filter them with winquake. If you don't like the pass band you can change it. For teleseismic events on my system I use a pass band between 0.03 & 0.3 hz. For local events I use a high pass around .5 to 1 hz.

ChrisAtUpw@....... wrote:
        In a message dated 02/02/2006, jonfr500@......... writes:
  I have set the raw data on digital filtering, but that one is on 5.5Hz
but the online graphs are now on 4Hz. It appears that the noise is
somewhat above 10Hz (there is noise on 10Hz, but alot less then if i
record from 2Hz to 60Hz), maybe above 6Hz.  I just haven tested it
properly yet. I do not know how this filtering will effect my abliti to
detect earthquakes.
  
  Hi Jon,
   
      Record 'sample' traces at the maximum bandwidth of 20 Hz, including noise at various times and a few local quakes.
   
      If you only view from maybe 3 to 5.5 Hz, you may miss some quakes.  
   
      Then view these traces putting in varying frequency low pass digital filters, using Winquake and see how to make the quake traces easier to read against the background noise.
   
      Regards,
   
      Chris Chapman
  

Hi Jon
  
 I agree with Chris. I record my quakes as raw data then filter them with winquake. If you don't like the pass band you can change it. For teleseismic events on my system I use a pass band between 0.03 & 0.3 hz. For local events I use a high pass around .5 to 1 hz.

ChrisAtUpw@....... wrote:
  
    
  
In a message dated 02/02/2006, jonfr500@......... writes:
  
I have set the raw data on digital filtering, but that one is on 5.5Hz
but the online graphs are now on 4Hz. It appears that the noise is
somewhat above 10Hz (there is noise on 10Hz, but