Hi all:
Some of you probably know that my job in Pacific Bell allows me to come
across the strangest things. Like horses that won't go near pole mounted
repeater cases (ultra sonic whistling from air pressure leak),
evaluation of Ground Penetrating Radar at a graveyard or even reports from
our corporate offices that their telephone instruments were emitting 3 loud
beeps and causing blood-shot eyeballs and headaches.
I get stuck evaluating all kinds of different noise phenomena.
For the past 6 months or so, I have been following the troubles of a local
ham who has been complaining about high power-utility caused noise which had
essentially shut his hf operation down. He is a rag-chewer and sometimes
dxer.
He has a very nice Force 12 20-10M yagi (including WARC) mounted at about
60' of military surplus aluminum tower (resembling Rohn 25). This tower
does not have bolted together sections. The sections are held together with
what resembles "hood-pins". You know, what holds the hood down on Racecars
and hotrods. But I digress.
His radio is a TS-830 and he uses a home brew amp - pair of 813's. The
station is fairly well put together and is grounded fairly well.
The problem he has is this:
He will pick out a clear 20M phone freq. like 14.193 . There is no power
line noise present at the time. He will transmit several dits and lo!, his
clear freq. was full of power utility hash!! The bandwidth of the noise was
about 20 Khz or so. He moved freq. and did it again. Amazing!!!
The power company eventually replaced a lightning arrestor and the ham
rewired one of his neighbor's attics (the ham is a licensed electrian).
My problem is: What can store frequency information and transmit noise that
lasts several seconds after the transmitter is keyed? My original thought
is that someone had a spectrum analyzer controlled by a GPIB controller
which also controlled a noise transmitter that is capable of changing center
freq's.
Or moon-bounce noise.
Can a transmitted signal cause a dielectric breakdown of a power circuit's
compontent(s) that will last for that duration? Is it Hale - Bopp?
Time to touch my retirement package and look at a KH8 qsl card.
Eric, K6GV
edwoods@pacbell.com
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