[RFI] RFI Canceling RFI?

[Tom Rauch]

>  > I turned on a second compact fluourescent light while
>  > listening to my shortwave radio, the first caused RFI,
>  > the second CANCELLED it!!
>  >
>  > But the first only caused RFI in the same room as the
>  > radio, the one in the other room had no effect on the
>  > radio by itself.

It's very easy obvious what happened when we work through
this.

1.) Only one light makes noise, he stated that.

2.) The second lamp that does not make noise, when placed
across the power mains, reduced noise from the only RFI
generating lamp.

The can only be one thing happening. The second lamp is
loading the line and changing something so the power lines
are detuned for noise (so it is a less efficient antenna or
less well coupled to the RFI generating lamp).

At my old house in Conyers, I had bad noise coming in on the
power mains. The noise was generated in my neighbor's house.
What I did was build a bypass capacitor with two 120VAC
rated .01uF capacitors, each one tied from one side of the
line to the safety ground, into a plug.

I just moved that plug around to different outlets until I
found one that detuned the power lines, and made the noise
radiating from the lines in my house disappear. The noise
virtually vanished even though I'm positive the source of
noise several hundred feet away still remained.

It's almost certain a the same thing is happening.

73 Tom