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
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|