[RFI] 160 meter boradband noise tracked down to apartment complex

David Cole dave at nk7z.net
Fri Oct 24 19:53:04 EDT 2014

Thanks for sharing!  Was interesting, please do let me know what you
find was the cause!
Thanks and 73's,
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On Fri, 2014-10-24 at 14:23 -0400, Don Kirk wrote:
> Recently noticed an increase in my noise level on 160 meters, and a about 3
> weeks ago I tracked it down to a new apartment complex which is located
> 0.41 miles away.  Today I noticed that the signal had a repeating pattern
> of approximately 30 minutes on and 5 minutes off when listening at my
> house, so I jumped in the car and drove over to the apartment complex to
> make sure the signal at the apartment complex had the same repeating
> pattern and was in time sync with the noise at my house.  Thankfully it
> was, and I made recordings at the apartment complex today showing I could
> predict when the signal would go off and come back on based on the time
> pattern I was following at my house.
> I have created a website documenting my direction finding activities for
> this broadband RFI case, and uploaded my prediction recording today.  Here
> is the link to my simple website that documents this case :
> http://www.youtube.com/watch?v=6AiBarOvMbs&feature=youtu.be
> I contacted the apartment complex today notifying them that I was now 100%
> confident that the broadband noise was originating from their building, and
> will now work with their management to locate the exact source so they can
> follow up with the manufacturer of the equipment for resolution.  Based on
> what I have heard so far it sounds like a motor (probably a variable speed
> motor controller), but that's just a guess at this time (sounds like it's
> winding up in speed when it first comes on and you can hear this on the
> recording I made at the apartment complex today).
> Just FYI, and another very interesting one to track down.
> 73,
> Don Kirk (wd8dsb)
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