Topband: Electric Fence QRM

Pete Smith
Sun, 01 Dec 2002 09:49:31 -0500

At 08:58 AM 12/1/02 -0500, Tom Rauch wrote:
>Older fence changers are long periodic raspy buzzes that cycle every
>few seconds.
>Of course small transformers with thermal overload switches, like
>doorbell transformers, can cycle off and can other things
>like electric heating devices.

I found a very loud emitter here - S9+20 buzz when on, nothing when off, a 
few seconds in each state.  Turned out to be an electrically heated dog 
dish with a bad thermostat, located 100 feet from one element of my 80m 

I really don't think there is any substitute for sniffing for noise with at 
least 2 AM radios, one MF or HF, the other in the V/UHF range.  If you can 
hear it on the lower frequency, but not on the higher, then you're 
relatively far away (noting, of course, that an electric fence can 
propagate noise a long way from the actual arc).  My little aircraft-band 
receiver can even differentiate the noises from two different electric 
fences that run parallel on either side of a road, 60 feet apart.  You can 
use body shielding to do this, or just rely on signal strength.

73, Pete N4ZR
Sometimes a tower is just a tower