[RFI] a small win in the RFI project: LED traffic signal

[bill K7WXW]

My RFI battle continues unabated. While I've quieted most of the sources 
in the house (I still have to figure out how to tame the HVAC system), 
external noises sources continue to accumulate.  There are days, when 
the powerline buzz sets my baseline noise level at -80dBm, that I 
fantasize about buying ten acres in eastern Oregon, putting up a tower 
and running a remote station full time...

That said, I have a small victory to share.  I had a noise source that I 
could hear from 10 to 150 MHz. It pulsed and clearly seemed related to 
something turning on and off. Last weekend, while I was out hunting 
another source, I figured out that it was the traffic signal on the 
corner (we will ignore the fact that this took me a year to realize.).  
I called the city traffic department, which responded, within a couple 
of days. I talked to a city electrician who told me that several of the 
lights were LEDs with built-in power supplies.

He came by yesterday. Fifteen minutes of working with him convinced him 
that the LEDs were the source. This morning he pulled the LED units and 
installed incandescent lights. As soon as I confirmed that the change 
solved the problem, he asked if I would help them find a filtering 
solution because, at some point, the LEDs will be back.  Of course I 
said yes.

So that's a pretty good outcome, and fairly quick, too.

73 de Bill K7WXW

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brevity is beautiful.