Rich,
There is a fair chance that the noise is radiating from those power lines
that you mention. There could be a number of possible sources for the "ac
hum" type noise; identifying the culprit becomes the trick. One big help
would be if you could take the receiver "mobile" with a loop-type antenna
rigged as a large "sniffer". For example, if going closer to the power
lines increases the noise, then the source is probably external to your
property. Many times the fix then becomes cruising down along those lines
to determine where the source could be and trying to get it quieted (good
luck) when you locate it. One thought is that there is some controller or
system, possibly using thyristors, that shares your power feed and puts a
lot of junk onto the lines. Such a system is typically used in industrial
areas in conjunction with various processes. There is also the possibility
of something arcing on the power lines, but my past experience with line
arcing has resulted in noise extending well beyond 500 kHz.
If going closer to the lines reduces the noise, then perhaps something in
or near your house is the culprit. It does not necessarily have to be an
appliance, as such; certain types of lamps, electrostatic air filters, and
electric fence chargers could all be candidates if any of these are in use
around your place. If you think it is something in your house, turn off
circuit breakers one at a time to determine if the noise stops with the
tripping of a particular breaker. I think trying to determine an answer to
the external/internal source issue would be a good way to start limiting
the search. Best wishes for a succesful hunt.
73, Dale
WA9ENA
"Richard D. White" <Acts1x8@pacbell.net>@contesting.com on 11/16/2000
10:58:54 AM
Please respond to "Richard D. White" <Acts1x8@pacbell.net>
Sent by: owner-rfi@contesting.com
To: rfi@contesting.com
cc:
Subject: [RFI] Low band noise
Hello Everyone-
I have a Yaesu FRG-100 receiver hooked up to a
random wire antenna, and am experiencing solid
noise that sounds something like ac hum on anywhere
between 80 KHz. to 500 KHZ. I have no known
appliances running, the noise appears to always be
there, the radio works fine everywhere else in the
frequencies it covers. I have telephone wires and
ac lines on the pole in my backyard approx. 50
to 80 feet from the receiver. Could this be from
the ac lines, or from something else, and any suggestions?
Thank you for whatever suggestions you might have.
Rich
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