Ken,
Here's some other good links and articles on power line noise on the ARRL
web page:
http://www.arrl.org/power-line
73, de ed -K0iL
-----Original Message-----
From: Kenneth G. Gordon [mailto:kgordon2006@frontier.com]
Sent: Sunday, March 23, 2014 7:29 PM
To: Ed K0iL
Cc: Rfi@contesting.com
Subject: Re: [RFI] My RFI battle....progress report.
On 23 Mar 2014 at 13:45, Ed K0iL wrote:
> Ken,
>
> Based on your latest description, are you looking for narrow-banded
> noise spikes?
No.
> Or is it really very broad-banded--only being stronger at the resonant
> frequencies of the antenna you're using?
Yes. Exactly, in fact.
> Power line noise is always very broad-banded getting weaker as you
> tune higher in frequency
That is exactly what I am experiencing here
>--this is more obvious when using a broad-banded log-periodic antenna
>like I have at work. Whereas the really strong, narrow-banded, spiked
>noises are usually generated by various in-home devices like TV sets
>and computers.
I have eliminated those from consideration: I connected the FT-890 to a
battery, and killed the house main breaker which turns off EVERYTHING in the
house.
There was absolutely no change whatever in the noise. None. Zero. Nada.
Conclusion: it ain't in my home. :-)
> Also keep in mind when tracking power line noises, you will find RFI
> sources everywhere,
Boy! Ain't that the truth!
> but not all of them, and probably only a few of them will cause RFI
> noise to your ham antenna because of standing waves (peaks and nulls)
> along the power lines. The best way to determine if the noise you
> tracked down is the same noise you are hearing at your ham shack is to
> get a visual waveform reading on a scope.
Although I do have a portable 20 MHz dual-trace scope, I don't have it in
the shack at the moment. It is in storage. I am hoping I won't have to dig
it out. In the meantime, I am using Spectran and a laptop.
> This waveforms method is recommended by Mike Martin, K3RFI, of RFI
> Services, and is described in the book "AC Power Interference
> Handbook" by Marv Loftness, KB7KK. I'll attach a QST article that
describes this method.
Thank you. I'll read it immediately.
> Your power company should be using this waveforms method to track
> power line noise and reduce the amount of RFI repairs they need to
> make to meet the FCC's Part 15 requirements. Why fix noises that do
> not cause RFI to any licensed services? (or at least have not
> generated and complaints!) This makes both the power company and the ham
happy.
Yes. I am in contact with a power company employee who also happens to be a
ham, and is also in charge ot taking care of RFI complaints. If things go
well, I may see him next week.
> Good hunting and GL!
Thank you, Ed.
vy 73,
Ken W7EKB
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