In article pan.2006.08.31.17.10.46.51000@Quetzalcoatl,
Bob Dobbs EC42 wrote:

They aren't trying to phase out the desirable signal.

A noise bridge works by subtracting the noise from the signal.

He's not talking about a noise bridge, which seeks an impedence null in an
antenna system, and is sometimes used as a tuner tuner.

OK, "noise cancelling bridge", according the page off the web that
I built mine from. (Something like Doug's Noise Cancelling..., and
the "ARRL RFI handbook").

A "bridge" is a old general name for a circuit that works by subtracting
one signal from another by means of two "arms", (ie. matching networks).
The output could be a meter, or in my case, a transformer winding that
feeds the antenna input.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)