Bearing in mind the very strong signal strength on 2m, the source must have
been fairly close to Doug's QTH - my guess would be on the order of not
more than 1/4 mile, at most. If Doug did hear 60 Hz components to the
signal, then I would agree that your conjecture is reasonable and possible.
I would add only that another possibility could have been a burst of corona
from the power lines, possible due to some defective or dirty insulators.
Years ago, I had very severe 60 Hz-related interference on 2m FM (not a
usual circumstance!) that had me stumped as to the cause, especially since
it was of an intermittant nature. Then, one humid summer morning as I was
leaving the house for the work commute, I heard the unmistakable sound of a
corona discharge in the air. It was coming from a power pole that held 3
big pole pigs that were used to feed 3-phase power to a supermarket, and
was located about 100 feet from my property.
I called ComEd, the local power utility in the Chicago area, and gave them
the pole number and physical location. By the time I got home from work
that evening, several hundred feet of new INSULATED high-tension line had
been run and the problem never returned.
> [Original Message]
> From: Alan NV8A <email@example.com>
> To: <firstname.lastname@example.org>
> Date: 3/10/2011 9:11:09
> Subject: Re: [RFI] Interesting Noise
> On 03/10/11 08:38 pm, Doug Rehman wrote:
> > I had a radio listening on 144.200 USB last night. The band was
> > quiet when all of the sudden a 59+20dB noise came on. Immediately after
> > hearing it, I realized that a major rain downpour had commenced. Within
> > minute or so the noise began to weaken and was totally gone in a few
> > minutes.
> > We've been dry for several days before the rain. This is the first time
> > heard this noise before.
> > Anyone have any idea what specific power line conditions or equipment
> > have generated it?
> Conjecture: crud had accumulated on the insulator(s) but caused no
> problem as long as it was dry. The rain at first rendered it conductive
> (causing the interference) but then washed the crud off: no more wet
> crud, no more interference.
> Alan NV8A
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