If it was wet or rainy, I had a similar sounding noise caused by a bent
squirrel guard on top of a power transformer. It started with a steady
pulse of noise with the start of rain, much like the sound of a Jacob's
Ladder. Then the off times shortened up and became more random until it was
on all the time. A new squirrel guard fixed that problem.
It also sounds similar to loose power pole hardware on a windy day as well,
and probably several other possible devices.
73, de ed -K0iL
-----Original Message-----
From: RFI [mailto:rfi-bounces@contesting.com] On Behalf Of Gary Smith
Sent: Saturday, December 01, 2012 11:15 PM
To: rfi@contesting.com
Subject: [RFI] RFI with sound bites
I'm having a horrific level of QRM which seems to bother 160M and 30M the
most. My inclination is it's a street light that is causing the noise as I
often notice it at gray line times. I was working the ARRL 160M contest and
it started up around 11PM local time. It was sufficient to ruin any chance
of QSOs during the contest so I taped it first with a 200Hz filter on CW and
you can hear what it sounds like to me. no file is more than 400k in size.
Its often a repetitious rhythm of buzz that happens 2-3 times per second
with occasional dead times of several seconds and then back to it again.
Sometimes it is persistent for several minutes and then back to the
buzz-rhythm.
Here is a view of the QTH. My house is the last one, at the end of the road
& next to the rail line. I am sandwiched between two state parks. Other than
Amtrak being beside the house and the people on the road south of me, there
is no other house or signal generation within a mile. Mt antennae are wires
in trees next to the salt marsh.
http://tinyurl.com/cy7zv7h
Here's #1 with the 200HZ filter during the contest at the bottom of the band
and then tuned below the ham band for no CW in the background for
comparison.
http://doctorgary.net/1-QRM-2.8KHz-CW-filter-160M.mp3
Then I recorded the same conditions on LSB with a 4K filter. I did the same
and dialed below the contest for comparison.
http://doctorgary.net/2-QRM-4KHz-LSB-160M.mp3
So as often happens, it stops for no known reason. I went outside with the
AM and got half way down the drive and it stopped. I saw no street light
flickering. I came back and made a similar tape with 4KHz LSB and you can
hear the difference in what I can hear. I also drifted below the band for
comparison
http://doctorgary.net/3-QRM-gone-4KHz-LSB-160M.mp3
Sat at around 7 AM it started and I had to stop calling CQ and quit because
I couldn't make out anyone who wasn't extremely loud.
Any idea what this sounds like it might be so I can deal with it?
& thanks!
Gary
KA1J
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