I've tracked line noise to lightning arrestors, though sometimes I've
been able to hear ultrasonic noise. However, as others have pointed out,
any two poorly bonded pieces of metal near the lines can cause noise,
and it's quite possible the arc is behind something blocking the
ultrasonic noise.
Of course, it's always crucial to make absolutely sure you are tracking
the right source by correlating its behavior with what's really
bothering you back at the station. It sounds like you have already done
this, though. My favorite method is to relay the noise from the station
receiver so I can hear it when I'm standing by the pole with the VHF and
ultrasonic trackers. There are almost always fluctuations in the noise,
which will match when you have the right source.
73,
Scott K9MA
On 1/11/2021 1:20 PM, Charles Plunk wrote:
Long Story but will try to keep it to my point. I have triangulated my
power line arc to a pole. Fairly typical 3 phase old residential but
busy pole. Insulators, disconnects, lightning arresters, a
transformer, etc. Pole is a junction as the 3 phase goes off in 3
directions from that pole. Arc is not affected by rain. And I cannot
hear it with my ultrasonic dish. In the past I have pinpointed bad
hardware on other poles with the dish.
I suspect the lightning arresters. There are 3 on there, one for each
phase and I assume very little way I could tell which one. Rural
utility, knows little about and/or is not concerned about arc rfi
other than past dealings with me and TVA (power distributor who does
have rfi location capabilities but is rather difficult to get them out
to do).
And now the arc is intermittent. Today its pulsing about every second.
Next week it may get solid for a while or go away entirely. And of
course if TVA comes out, it will be gone.
What hardware, other than lightning arresters (arcing internally)
would not be affected by rain and I could not hear with the dish?
Would it be reasonable enough to ask the util to replace the lightning
arresters before bugging TVA?
Any thoughts appreciated.
Thanks,
Chuck
AF4O
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Scott K9MA
k9ma@sdellington.us
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