Sam Morgan wrote
>
> And after our first overnight 25 degree freeze of this winter,
> the next day when the temp went up to over 80
> (it's WTX what can I say)
> the noise came back with a vengeance and made any hf operations impossible
> until the next day when the temps were back to seasonal normals. 40s-60s
>
> Any clues what I might need to look for?
>
Sam, Very likely its loose pole hardware on the high tension
connections, most likely at the transformer, which can easily be found
by banging poles with a sledge hammer while listening on a AM radio. It
is easier if you have a 10 or 6 meter radio or even a Bearcat scanner
with VHF Aircraft channels which will help in narrowing down the
location. Use some discretion when you bang on the poles. Sometimes
the connection is so loose that the brass washer is dancing. I think in
your case the heat causes the metal expansion thus increasing the space
to a connection and an arc occurs.
The first time I did this in Minnesota the police were called "that
there is a crazy person with a sledge hammer going around banging on the
power poles" and they arrived with a mental intervention specialist!
I did find an alternative that is less conspicuous....by backing the
truck (with a good but gentle bumper) up to the pole and giving it a
slight bump while in reverse. Problem is that this can cause the HT
line to oscillate a bit and the noise may sputter and even go away for a
while but it is not necessary that pole. That is why the AM RX at VHF
really can narrow down your choices.
On nice thing, if you can call it that, in the tropics is every 5 years
or less we get a big hurricane and a lot of old stuff is replaced. Most
of the copper is gone and replaced with aluminum wire which uses
excellent AL/CU compression fittings. I didn't think it would improve
things but here it sure has with new plant installations now and then.
Most of the work is done by Alabama Power's National Guard and those
guys are awesome. I always have a chest full of ice and some Coors
light to give them when they work the neighborhood after a storm.
Good Luck
Herb, KV4FZ
>
>
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160 meters is a serious band, it should be treated with respect. - TF4M
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