[RFI] Overnight interference

KD7JYK DM09 kd7jyk at earthlink.net
Sun Jul 24 23:40:09 EDT 2016

Remember those laser star show things that came out a Christmas or two ago?
I recall comments of them wiping out large areas, both RF-wise and

I was at a CVS Pharmacy store the other day and the shelves are filled with
the bloody things, part of their "back to school" program.  The manager
said, "I have no idea what these things have to do with going back to
school...".  Still $40.  As soon as they hit 10-15 or they show up in the
thrift shops, I'll get one to play with.

Listened to your recording.  I hear a hum, but don't see anything at 60 Hz.
I do see consistent traces at 240 Hz.  As for your thought of data, I
don't see any patterns, but there is an odd data burst that can be heard
around 15 seconds, maybe something else on the frequency you were
monitoring?  I did a spectrogram of the noise, it's intentionally formed
to be within the "voice" range of a telephone or radio.  Are you using some
sort of filters in your receiver?

Generally, the noise sounds like a light on a pole I watched as it turned on
and off and produced similar noise as well as a malfunctioning LED street 
These were both limited in frequency range by their physical
characteristics, that is to say, for example, noise from 1-4 MHz.


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