[RFI] Noise Help

Jim P jvpoll at dallas.net
Sun Apr 23 20:25:14 EDT 2006

First impression - 

This sounds characteristicly like a shorted or 'cycling' doorbell
or thermostat transformer (it is that time of year, it is warming
up, those transformers in the attic see a really wide temp 
swing and the bimetallic thermal breakers get funny).

I tracked down one of those xfmrs at a HAM's house spring 
last year or the year before.

HE was having noise issues with AM Broadcast band - and 
he had suspected the buried AC service in the alley - was going
to check it with transistor potable (but hadn't yet).

DF indicated the front half of his house in the center, strongest
in the area of the door (near doorbell pushbutton et al).

I used a CH 3 dipole cut dipole and a TV field strength meter,
as these are peak-reading (normally reads NTSC synch tips) 
and it indicated/nulled off the ends beautifully.

He was really surprised and thankful to have found the source.

Jim  /  WB5WPA
----- Original Message ----- 
From: "K6IA-Howard Stephenson" <kg6wp at yahoo.com>
To: <rfi at contesting.com>
Sent: Sunday, April 23, 2006 11:55 AM
Subject: [RFI] Noise Help

> This is a strange one. The noise covers HF-440, very
> strong so it's close. It sounds to me like an AC
> arcing noise but I can't peak it on the power lines in
> the area. It peaks towards some residences behind my
> house, including a in-law shack and 2 work
> shop/storage buildings in back yards which all line up
> on my 440 beam and make it difficult to RFI to exact
> area. I'm wondering if it could be a problem with a
> service panel or a short in some wiring.
> The noise comes and goes at all hours. In the wave
> file it does short bursts which is typical then it
> could be quiet for an hour or so.
> Any ideas or suggestions would be appreciated.
> Link to noise:
> http://tinyurl.com/qdg5x
> It's a big file almost 2 megs.
> 20 meters, JA contest with S-9 JA and the noise covers
> the signal
> Howard Stephenson  K6IA
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