Bob Dobbs EC42 wrote:

On Wed, 30 Aug 2006 16:32:14 +0000, Mark Zenier wrote:

In article .com,
Steve wrote:
In some contexts, when noise is a problem, people will say that you want
to keep the "noise antenna" that you use with the ANC-4 as small as
possible. This is because you want the noise antenna to hear *only* the
noise, which will be phased out, and not the target signal, which you
don't want to be phased out. The suggestion here is clearly that, if
your noise antenna *does* hear the target signal, you're going lose
signal along with noise.

Answering Steve;
since I seem to have either lost or never saw his original post.

What you say above is correct.

However, when people use the ANC-4 to establish phased arrays of two or
more antennas, this is usually with a couple of serious antennas, widely
separated, *both* of which can hear the target signal.

In this case they aren't using the ANC-4 as much for noise reduction
alone, but for signal enhancement, and phase select for desired signal
versus unwanted interference, noise and other stations.

Hence my
question: When the ANC-4 is connected to two largish antennas, both of
which are capable of hearing the target signal, what prevents the
desired signal from simply being phased out? Is determining what gets
phased out just a matter of carefully adjusting the controls on the
ANC-4?

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.

Yep, a noise bridge can be quite handy for setting up an antenna tuner.

dxAce
Michigan
USA