Re: [RFI] W8WWV noise

[Pete Smith <n4zr@contesting.com>]

At 10:36 PM 2/16/04 -0600, W0UN -- John Brosnahan wrote:

> Greg, W8WWV asked me about his noise problem and I am
> checking on some radar and sounding systems to see if anything
> is out there that might make this noise.   But I also thought
> the collective wisdom of the group might have some ideas.
>
> His description of the noise is at:
> http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/DXNoise.htm
>
> And he has a 30 second mpeg at:
> http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/Noise75.mp3
>
> If you have any good ideas let me and/or Greg know.
> "Greg Ordy" <ordy@seed-solutions.com>

This may be totally off the wall, but 15 years ago I was trying to finish 
my 5BDXCC and put up an 80-meter full-wave loop behind my townhouse.  I was 
immediately confronted by a signal that sounded much like what Greg 
describes.  It was discrete, only on a small band of frequencies, but with 
some audible short-term changes evident.  I *think* (from memory) the sound 
was much like his recordings.

In my case, there were actually two bands of frequencies in the 80m band, 
one ca. 3505-3515, the other at 3765-3775.

I went around my neighborhood with a portable shortwave radio, and 
eventually determined that the noise was radiating from one house.  The guy 
was willing to be helpful, and so I walked around his house with him trying 
to determine where the noise was coming from.  At one point, he switched on 
the lights in an upstairs bathroom, and the noise suddenly ceased.  The 
lights were incandescent, and there were no complex electronics anywhere, 
just a 72-cent Leviton silent SPST wall switch.

To cut to the chase, I replaced the switch for him, and the noise 
disappeared.  A few days later, I noticed another, on a slightly different 
set of frequencies.  I traced that one to a 3-way switching setup in the 
dining room of a townhouse across the street.  Again, the homeowners let me 
replace a switch, and again the noise went away.  I think that switch cost 
$1.15 -- again, no dimmer or anything else fancy, just a switch.

I have no idea what physical mechanism was responsible, but empirically, 
that's what it was.  Particularly given Greg's description of the signals 
that appeared at different frequencies, from different directions, I have 
to wonder if he isn't experiencing something similar.

73, Pete N4ZR
Check out the World HF Contest Station Database
Updated 9 Jan 04
www.pvrc.org/wcsd/wcsdsearch.htm



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