RFI
[Top] [All Lists]

[RFI] Re: rfi-digest V1 #80

To: <rfi@contesting.com>
Subject: [RFI] Re: rfi-digest V1 #80
From: James L. Keyes" <jkeyes@mtnhome.com (James L. Keyes)
Date: Thu, 09 Jul 1998 11:34:46 -0500
rfi-digest wrote:
> 
> rfi-digest           Wednesday, July 8 1998           Volume 01 : Number 080
Yo, Marty! I had the same problem last month and found the offending
light is a CdS photocell, a SCR (or TRIAC) and a small incandescent
lamp. When the light level dropped, the thing switched on and off at a
rapid rate and hashed up everything in the area! It turned out that the
lamp was visually feeding back to the photocell. The waveform was a
really weird sawtooth. I found that the little porthole for the
photocell was removable, so I took it out and cemented a 3/8 inch ID x 1
inch long kraft paper tube in its place to shield the photocell from the
lamp light. Everything got quiet and I can still see to go to the can in
the middle of the night!
I also looked for better designs and found a type that is an
electroluminescent disk, plugs in, runs all the time, draws about 12ma
and shows nothing on my spectrum analyzer. They are supposed to have a
minimum 10 year life and cost ~$4 at Sam's many stores.
73,
Jim Keyes WA1TQG/5
> 
> ------------------------------
> 
To: <rfi@contesting.com>
> Date: Wed, 08 Jul 1998 21:13:27 -0500
> From: Marty Tippin <martyt@pobox.com>
> Subject: [RFI] Nightlight Causes EMI!
> 
> Here's one I haven't read about or heard of before...  Thought I'd pass it
> along just in case anyone else runs into the problem...  I ran into this
> one while searching for some possible CATV leaks...
> 
> A nightlight with an electric eye in our downstairs bathroom was throwing
> out a tremendous hash - took me an hour of tracing with an AM portable
> radio to figure out where it was coming from (I replaced the light switch
> in the bathroom first because I thought it was the source - when I turned
> the lights on, the noise stopped; when the light was off, the noise came
> back.  Took me a while to correlate that with the nightlight going on and
> off... So I'm a little slow...)
> 
> Anyone know what it is in the nightlight that causes the problem?  I'll bet
> on the electric eye being at the heart of the matter.  In any case, that
> light will no longer be illuminating the bathroom at night...
> 
> Unfortunately, it didn't do much reduce the S5 QRN I have on 20m almost
> continuously.  So I'll be heading for the neighbor's houses before too long
> to see what wonderful noise sources I can find there.
> 
> - -Marty
> 
> ===========================================================================
>  Marty Tippin KI0LO   | Tippin's Law #9:  Stupid people outnumber the rest
>  martyt@pobox.com     |   of us by at least 5 to 1...
> ===========================================================================
>  http://hbd.org/users/mtippin - Marty's Homebrew (Beer) Gadgets Page
> ===========================================================================
> 
> - --
> Submissions:              rfi@contesting.com
> Administrative requests:  rfi-REQUEST@contesting.com
> WWW:                      http://www.contesting.com/rfi-faq.html
> Questions:                owner-rfi@contesting.com
> 
> ------------------------------
> 
> End of rfi-digest V1 #80
> ************************
> 
> --
> Submissions:              rfi@contesting.com
> Administrative requests:  rfi-digest-REQUEST@contesting.com
> WWW:                      http://www.contesting.com/rfi-digest.html
> Questions:                owner-rfi-digest@contesting.com


--
Submissions:              rfi@contesting.com
Administrative requests:  rfi-REQUEST@contesting.com
WWW:                      http://www.contesting.com/rfi-faq.html
Questions:                owner-rfi@contesting.com


<Prev in Thread] Current Thread [Next in Thread>
  • [RFI] Re: rfi-digest V1 #80, <jkeyes@mtnhome.com (James L. Keyes) <=