For the last couple of weeks I hear very strong noise that is 20 over s-9 on
160M. It generally is a string of broadband pulses. Each pulse is about a
second long, with about 100 msecs between pulses. The first pulse is
shorter than the rest, maybe a half second in length, then the rest of the
pulses are all the same length. The pulse strings last anywhere from 10
seconds to a few minutes, then quite, then back on again up to 5 or 10
minutes later. The noise is sometimes off for as much as an hour, then
starts the pattern again. The noise content of each pulse is very random,
and does not appear to have the typical 60 Hz components heard from power
lines. The noise can be heard from broadcast band up to 10 meters, but is
much stronger on the lower frequencies. It destroys reception on 160
completely.
I have not yet been able to locate the noise to a specific pole or
house, but I know within a few hundred yards which of several residents from
which it may be radiating. (Generally North of me, from where of course the
best DX arrives. Using my 4 square and beverages, I can bracket the
direction, but since it is being radiated along the power lines to the North
that subtend an arc from about 300 degrees through North to 100 degrees, it
is difficult to pin down the source using station antennas. )
Has anyone experienced anything like this? Before I start working with
the neighbors and going on their property to refine the search, I'd like to
get an idea of what device it might be. If you know of any device which have
a similar pulse signature, please let me know. Thanks for your help.
Bob N7UA
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