My friend Charlie, WA2NWN, recently reached out to me for assistance with a
strange interference problem. He uses a Yaesu Ft7900, with a custom built
60 ft separation cable, to replace the stock separation cable. This
installation has been in use for several years without any problems.
Shortly after Verizon was doing some work near his home, he started
receiving comments about what sounded like an FM broadcast station mixing
with his audio, on both 2m and 440 transmissions. Despite the past
performance I suspected the separation cable. Replacing the custom cable
with the original one or omitting it did remove the interference, but why
did previously work? Charlie reached out to Verizon who sent a tech out.
Nothing was found.Here in NJ we haven’t had rain for over two months.
Coincidentally we finally had one day of rain, and the interference
disappeared, but only for one day.
As the discussions continued Charlie also mentioned that he had to turn on
his outdoor Christmas lights. Hmm, I asked are they incandescent or LED?
They were incandescent, but he installed new LED replacement bulbs a few
years ago. He also noted that a few needed to be replaced. So, multiple
diodes connected to a lot of wire! Sounds like the perfect storm for some
RF mixing. When the dead bulbs were replaced, no more interference! I’ve
been licensed for 53 years but this is a new one for me!
*Best 73 de WA2SQQElmwood Park, NJ"The only dumb questions are those we
don't ask"*
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