In a message dated 22/05/2006, jonfr500@......... writes:

I more  often then not I get a one single line spike into my earthquake 
recording,  those spikes can be seen on my online tremor plots. The wire that i use 
to  connect to the amplifer board is near alot of electronic hardware, tv, 
vcr,  sky digital box, subscription tv box for local channel, tvo adsl tv 
decoder  box.



Hi Jon,
 
    One of the common causes of spikes may be the  inductive motor of your 
refrigerator switching on and off. It is likely to  effect the whole of the 
house wiring and can be difficult to  eliminate. Try switching your fridge on and 
off to see if there are spikes? 
    You can buy the Electrolux type fridge which just  has an electric / gas 
heater to drive it - no motor.
 
    Regards,
 
    Chris Chapman






In a message dated 22/05/2006, jonfr500@......... writes:
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  often then not I get a one single line spike into my earthquake recording,=
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  those spikes can be seen on my online tremor plots. The wire that i use to=
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Hi Jon,
 
    One of the common causes of spikes may be the=20
inductive motor of your refrigerator switching on and off. It is likely=
 to=20
effect the whole of the house wiring and can be difficult to=20
eliminate. Try switching your fridge on and off to see if there are spikes?=20

    You can buy the Electrolux type fridge which ju=
st=20
has an electric / gas heater to drive it - no motor.
 
    Regards,
 
    Chris Chapman