I made this video to help me identify a source and get some help with a
carrier and broadband interference noted on the low bands. I have
identified two general signals. They have a significant AC hum. One is
strongest to the West of my location and peaks at about 20dB over S9 On
the meter. It starts in the AM broadcast band and is heard up to about
8.9MHz. It is strongest about 3520kHz. You can see it and hear the
noise in the video posted on YouTube:
http://www.youtube.com/watch?v=chWUMQUBqlw&feature=c4-overview&list=UUA9lAJmr2N3s5BkA7XyLDGg
In the background, you see and hear a second carrier about S9 This runs
through the 160m band and stops abruptly around 3.9MHz. It is strongest
to the East of me, based on the K9AY antenna.
I haven't yet put my spectrum analyzer on the antenna input but plan to
do so. The stronger signal starts daily around 7PM. It is off by the
time I wake up. I am hearing this on two radios both with direct wire
antenna into the radio and via a listening antenna with preamp
operating. I have been through my house with a battery operated SWL
receiver tuned to this frequency. I don't see a source inside my house.
I have cut all the breakers in the house sequentially and there was no
drop in the signal. I do have lots of fluorescent bulbs in the house
but they can all be turned off with no difference of the signal. As a
matter of fact, I walked around the house with a flashlight after the
entire house was darkened and could not find the source. As I walk
around the building with the radio, the signal is strongest around any
of the refrigerators or devices with motors. If I shrink down the
antenna, I do not see any source within the house. I even shut down the
laptops and disconnected the power supplies with no benefit.
I really do not know what to do about this. Does this sound familiar or
similar to anyone?
--
David J Rodman MD
Assistant Clinical Professor
Department of Ophthalmology
SUNY/Buffalo
Office 716-857-8654
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