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Re: Topband: RFI - lots of it

To: "Topband@contesting.com" <Topband@contesting.com>
Subject: Re: Topband: RFI - lots of it
From: Jim Murray via Topband <topband@contesting.com>
Reply-to: Jim Murray <adkmurray@yahoo.com>
Date: Wed, 28 Oct 2015 05:12:16 +0000 (UTC)
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Thanks Tom.  I think I have it narrowed down with a portable.  The line going 
to our home is spliced to the main line along with another line going to a 
building across the highway. At that spot there is a ball of wires with some 
kind of what appears to be a metal fixture (clamp etc.).  Just not familiar 
with hardware used.  Noise drops at building across the highway around the 
meter etc. and down the main line in both directions.  Noise just below the 
junction is loudest I could find.  Thanks to all the good people on the forum 
I've accumulated a folder of RFI, grounding and bonding info that I'm sure 
contain the solution.  One lesson learned is to check 160 before you start 
laying in radials etc.  I didn't have an antenna that I could tune that low.  
At our old qth I left a nice radial system and moved here last fall and spent 
the summer working on another radial system.  What's ironic is that the power 
company put in a new feed line to the  house since they said the old one was 
corroding copper etc..  They did it for free as long as we would replace the 
meter and line to the main panel, which we did. The ironic  part is they left 
me the old wire and I used it for one of the radials:).  I think it weighed 20 
pounds, all copper.  Regards,jim/k2hn

Wet weather noise is often corona related, but sometimes defective 
insulators, cracked, scored, or dirty. I had problems with 345kV line corona 
in Ohio when the weather was damp.

Dry weather noise is often slack spans allowing the metal pin joints or ball 
and socket joints in insulators to arc from capacitive coupling. The metal 
on metal corrodes and makes a tiny layer of oxide that arcs from capacitive 
coupling and leakage.  Hitting a pole with a hammer finds that, because it 
shakes the wires and wiggles the metal joints.


There are so many different things that can cause noise, however, that any 
Internet diagnosis is mostly a wild guess.

The best thing to do before doing anything is try to track it with a VHF AM 
radio, like a portable aircraft radio. I have commercial noise locating 
equipment, but the last time I lent it out it came back broken.  :(

73 Tom 
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