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

Don Kirk wd8dsb at gmail.com
Fri Oct 24 14:23:28 EDT 2014

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 :

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.

Don Kirk (wd8dsb)

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