Don't be too quick to blame the electronics. Sometimes there isn't an 
immediate explanation. One unique situation took over two years to 
figure out. When the 4 acre lake behind the house freezes solid, the 
water drains out from under the ice. As the water disappears, the ice 
cracks. If you are outside you can hear this happening. I recorded the 
time while walking the dog one time and went in to check the data. Sure 
enough, the cracking of the ice was causing one of my unusual data 
sequences. On one occasion a USGS team came through my side of the city 
(about a mile away) with a thumper truck creating seismic waves. It was 
two days later when a local newscast did a story on the truck's activity 
that I figured out what I was seeing. Very strong winds used to cause me 
trouble. (I am talking 50  to 70 mph gusts.). Thunder (close by) 
occasionally is detected as well as the Blue Angels during shows on our 
riverfront. Quarry blasts used to arise my interest but now I find them 
an irritation if an earthquake arrives at the same time...and that often 
happens. I had to turn off my 200 watt 10 meter repeater because of 
radiation interference when the last sun spot cycle. Oh, yes, one of my 
first successful discovery. There is a walnut tree about 10 ft from the 
house and 25 ft from the seismic units. When the walnuts fall off the 
tree and hit the screened-in porch roof, a sharp peak occurs on the 
short period units.
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