[RFI] CFL Noise Update - Neighbor Removes Burned Out CFL

Tony dxdx at optonline.net
Tue Oct 9 02:01:20 EDT 2012


I recently discovered that my neighbors CFL lighting was causing RFI. I 
managed to get close the light with a portable HF rig and found the 
noise was identical to what I was hearing in the shack; same 
frequencies, same noise characteristics. I should mention that the bulb 
was burned out.

The problem with pointing the finger at the light as the only RFI source 
was that the noise would shift in frequency when I turned a light switch 
on and off in my home! I recorded the frequency shift "trick" on video: 

I shut the mains to see if the noise was coming from my home, but it was 
still there with the breakers off. The light switch had no effect on the 
noise as long as the mains remained off.

Long story short:

The noise went away immediately the moment my neighbor removed the 
burned out CFL. An identical CFL that was working emitted much less 
noise. He hasn't replaced the bulb yet so we'll have to see what happens 
with the new one.

The puzzling thing about all this is how a light switch in my home could 
have an effect on the noise coming from a neighbors CFL? It doesn't 
appear coincidental because the light switch "trick" hasn't happened 
since my neighbor removed the CFL. It's been a while now and all is quiet.

Any ideas?

Tony -K2MO

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