Kim,
You've already had several other excellent responses, so mine will be short.
I've found it hard to get very accurate readings on HF, partly because the
noise can be radiated, partly because most folks (like me) don't have
4+element beams on HF.
I almost always start with 6m. With 5 elements from home, it gives me a
really good idea of the direction.
Then, in mobile and/or walking, with 2m/70cm AM receiver and small handheld
beams, the pinpointing is done.
The 2m vertical on the car may tell you when you pass a bad pole.
An Arrow 3-element 2m beam is pretty helpful.
An Arrow 7-element 70cm beam is outstanding.
Make sure to flip the beam back and forth -- vertical, horizontal,
in-between -- as you point at different poles. If there are several poles
close to each other that have a problem, it can be confusing, so multiple
triangulation spots could be needed. Sometimes you just find the worst one,
get it fixed, and if there is still a problem, do it again.
Write down the pole #, the closest address, and contact the utility.
By the way, in our day with heightened security awareness, don't be
surprised if someone questions you about pointing an odd-looking device at
poles. This has happened to me several times. A friendly smile and a brief
explanation have taken care of it for me, but I wouldn't surprise me if
someone called law enforcement. ;-)
The ARRL has lots of good info, as Ed mentioned, and my web page has (I
think) lots of good advice and references as well:
www.powerlinenoise.com
73, Dave N0RQ
-----Original Message-----
From: rfi-bounces@contesting.com [mailto:rfi-bounces@contesting.com] On
Behalf Of Kim Elmore
Sent: Saturday, October 09, 2010 1:39 PM
To: rfi@contesting.com
Subject: [RFI] Power Line Noise Conundrum
I have a recurring power line RFI issue. At one point, it seemed to
have been remedied, but has returned. It sounds similar to what I had
earlier in the spring. That was repaired by the power company along
with the help of a tornado (really!).
Now, though, I hear it again.
Trying to be helpful, I'm trying to track it down and have had
confusing results. First, I've tried chasing it with my rotatable
antennas as home. I have K9AY loops that have a good null off the
back. I laso have a 2 el 40 beam, along with a 20 m-10 m tribander
and a dipole for 30 m-12 m. Depending on the time of day, I hear it
pretty much everywhere relatively well, save for 20 m, which seems to
be the quietest.
On 80 m with the K9AY loops, I have minimum noise when the null is
either SW or NE; which strikes me as inconsistent.
On the 2 el 40 m bean, I get deep, narrow nulls off of what i believe
to be the sides when it is oriented either N or S. I also get a
weaker null when it's pointed roughly W, indicating the source is to my
East.
I don't hear much noise on 20 m. On 15 m I get a null to the N, but
on 10 m I get a null to the S! the antennas work as they should (CW
signals are peaked when the antenna is pointed at their source).
Using the dipole, I get weak nulls when it's pointed N or S.
I have a corner reflector for 2 m and 70 cm but cannot hear anything
on either band when I use AM detection regardless of where it's pointed.
I drove around the area in my car, using my dual-band rig set for AM
detection. Using 2 m, I tended to hear it over a broad stretch along
a road that is about 1/2 mi to my east. I found a localized source to
my ENE when I went up to 70 cm. I suspect that is the source, as it's
very near a pole that carries quite a bit of hardware (lots off bell
insulators and lighting arrestors) and what appears to be a 25 kV line.
But I'm perplexed about the inconsistency I hear using my HF
antennas. Is this because of standing waves along the lines, or am I
hearing different sources? And, how can I use this to be most helpful
to the power company? They were very helpful the last time and I
don't want to send them on any wild goose chases.
73,
Kim Elmore N5OP
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