[RFI] Flourescent lamp RFI

Tom Rauch w8ji at contesting.com
Tue Sep 27 21:01:58 EDT 2005

> So I wonder if the cause of the RFI is really the
flourescent LIGHT (BULB)
> itself OR maybe it's the electronic ballast?

It is the ballast. Flourescent lamps generate a tiny amount
of broad spectrum RF energy from non-linearity in the
plasma, but it is very small.

Newer electronic ballasts are horrible. My newer shop lights
(I have about 32 dual 40-watt fixtures) generate all sorts
of RF trash including harmonic-rich AC modulated carriers
that move around as well as 120 Hz broadly frequency
selective buzzing. That noise is detectable hundreds of feet
from my shop.

The very same lamps swapped into older style transformer
ballasts impact sensitive receivers only when the antenna is
within a few feet of the lamp.

73 Tom

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