[CQ-Contest] Dimmer Switch RFI

[K9MA]

Here's what the spectum of a Lutron dimmer switch looks like:


http://sdellington.us/hr/RFI161127.jpg


There's a long tail upward in frequency for perhaps 70 kHz.  Repeats 
every 96 kHz, and it's quite stable.  That quiet range is only 20-30 
kHz, but I was somewhat lucky last weekend that one fell at the low end 
of 20.  The sharp cutoff made it easy to identify with a handheld 
receiver.  I mistook it for a switching power supply, but that's sort of 
what it is, anyway.  I can see many similar, but weaker, signals with 
the same sort of spectrum, no doubt devices of other neighbors in my 
urban neighborhood.  (Some of these others are switching at different 
frequencies, coming from different directions, etc.)

I bought the neighbors a replacement dimmer (Levitron), but we'll see if 
that solves the problem.  As others have pointed out, it could be 
mis-wiring or the LED lamps themselves.

73,

Scott  K9MA

-- 
Scott  K9MA

k9ma at sdellington.us