Lee,
Thanks for your message! You're the first
person I've heard from who has experienced a similar
type of noise as I'm hearing. I haven't yet found any
smoking guns driving the local roads in my neighborhood.
I also haven't covered every road yet within 2 or 3
airmiles of my location so I have more ground to cover.
73,
Scott, K1OA
From: Lee K7tjr <mailto:k7tjr@comcast.net>
To: rfi@contesting.com <mailto:rfi@contesting.com>
Sent: Sunday, June 20, 2004 11:21 AM
Subject: Re:K1OA Qrn noise (long)
I just listened to your .wav files and I can say I just recently tracked
down a noise that sounds the same here in Central Or.
One of the most fascinating things found during this investigation was
how I could receive different signal strengths on different bands until
I tried a new type of antenna. I had just built a shortened dipole for
receiving on 160 that has a high impedance buffer amp connected to it. I
am able to hear the interference at or near the same levels on many
different bands up to 30 mhz in my shack. Now as to the interference I
was able to find it after driving around all the local roads with
several different radios and antennas until one day I happened to be
dialing thru 28 Mhz band on AM. The interference was immediately
detectable as I drove down a long road with local power lines. It was
only about a half mile from my antenna farm. As I drove along a certain
road (I had been down this road many times using other frequencies
because I had found the noise on 75 and 160) I could hear the noise go
up and down in signal strength with each wavelength and increase as any
feeder lines crossed over the road. The best antenna turned out to be a
simple untuned loop of copper wire stretched in a square around the bed
of my pickup. It was insulated from but not spaced away from the bed.
Ignition noise from the pickup was a problem and I found myself coasting
down most of the hills so I could hear the QRM noise. As I drove past a
certain power pole the s-meter was pegged and the wideband and static
sounding noise was deafening. There was an undergound feed with a
lightning arrestor attached and after the power company came agreed that
the arrestor was the problem.. The power company interference man had an
ultrasonic small dish and he was able to pinpoint within an inch or so
where the actual arc was coming from. The moral to this long story is
that I too thought it just may be summertime static but I could find no
reason to have an s-3 noise level during the day on 160 meters. The
arcing to ground sounded purely broadband as the passband of the
receiver would not pass any 60 or 120 cycle component of the sound. The
arcing would occasionaly put out bursts that sounded also like lightning
static as well.. I have since been able to find 3 more power poles with
arcing and I am grateful that the local power company has a man that
cares assigned to interference problems. Lee K7TJR Oregon
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