[Elecraft] LED Lighting and RFI

[Jim Sheldon]

More to add to the good side of this.  Today, I replaced two 2 tube 4 
foot and one 2 tube 1 foot fluorescent fixtures.  The 1 footer and one 
of the 4 footers was in the kitchen and the other 4 footer was in the 
laundry room in the basement.

The fixtures used were by Livonia Lighting and the two 4 footers were 
type LBL4.  The smaller fixture was a round one that I replaced the 1 
foot fluorescent over the sink and it was a Livonia type FMML7840.

They exhibit absolutely NO RF noise that I can find on any frequency 
from VLF all the way up through 6 meters.  I had all other lights in the 
house off when I did the test and then turned all of them on and still 
no noise anywhere.  I now have ALL the lights in the house replaced with 
LED's.  Most are GE with the others Livonia Lighting types.  The are all 
of the "dimmable" variety and I suspect the big 4 foot fixtures have a 
switching supply in them as they operate from 90 through 270 volts 
without any tap or switch changing, but the supply is in a totally 
sealed metal box and if any RFI is being generated by that supply, it is 
apparently not getting out of the box.  I'm not saying they aren't 
generating any noise, simply that I can't find it if they are.   My 
antennas are close enough to the roof of the house (wood decking) that 
any radiation from the AC wiring couples easily to them and I have had 
switching supplies that were so bad they blanked everything out so I'm 
pretty darn sure of my findings in this case.  That said, I'm out of 
this thread in the interest of limiting the clutter.

Jim - W0EB