[RFI] HV powerline noise mitigation - success!

[rocketnj at gmail.com]

Hi All

Thought I would share this.

I've been plagued with powerline noise for years, especially bad on 15 and
40 meters. The Flex Radio wide noise blanker does magic on it as long as the
noise is constant, but on a low humidity, breezy day the noise comes and
goes so quickly that the WNB algorithm in the radio can't lock on quick
enough.

Today I was out and saw a Jersey Central Power & Light truck near a park
about a mile from my house. I started talking to the gentleman from JCP&L
asking which department handles my specific complaint (after explaining how
the arcing causes RF interference). My contact at JCP&L retired recently. I
explained I am fairly confident I had isolated the problem to the dead end
insulators that are at the end of the HV line coming into my neighborhood,
which happens to be on a pole on the corner of my property. He wasn't sure
who to contact but he was willing to ride over and take a look.

We met at my house. I explained tapping on the pole would cause the noise to
happen and it only usually is a problem on low humidity days, like today. I
brought up the Flex SmartSDR app on my iPhone to watch and listen to 40
meters while he took a small sledge hammer and gave the pole a whack. Bingo!
You could hear the crackle and see it in the panadapter and waterfall.
Whack, again you could see and hear it. He got out his push up fiberglass
pole and pused on the dead end insulators. The noise was concurrent with him
pushing the insulators. As the HV line swayed back and forth you could see
the noise floor jumping in sync. He changed the old ceramic triple insulator
with a polymer version. No more noise!

I'm sitting here listening on 40 meters listening. Relative humidity is 20%
(VERY low for northern NJ this time of year) and a slight breeze. No
powerline noise!

 

 

Dave wo2x