Fluorescent interference
 

Strangeness. I have a Shakespeare 2050 directional TV antenna on the boat.
Some of you may remember that I had blasted it as unreliable awhile back.
The remote control wouldn't work worth a darn, and the antenna would rotate
on it's own. I finally tracked this problem down as a bulb going bad in my
little 12V thinlite fluorescent fixture. Don't ask me the mechanism of
this... a fluorescent bulb causing interference with an IR remote! Anyway, I
noticed that when I turned the light on, one of the bulbs exhibited that
blue arcing at both ends before coming on. This was pretty noticeable, so
even though the bulb was still working, I replaced it with a new one. Wow!
Completely ended the problem with the TV antenna remote, and also eliminated
some interference with the SSB I had tracked to that fixture earlier. Even
stopped a little whine coming out of the exhaust hi temp alarm that I could
never figure out.

Just goes to show.... it's always something!