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Old September 1st 06, 10:00 PM posted to rec.radio.shortwave
Steve Steve is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 1,324
Default Question about the Timewave ANC-4


Steve wrote:
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.

snipprd the rest unrelated to the ANC-4's operation.



--

Echo Charlie 42
San Diego, California


Thanks for the info. Very interesting. I look forward to trying the
ANC-4. I'm going to try it with a variety of short wires, but I will
probably also try to use it in conjunction with a good quality active
whip (H-800 Skymatch). Should be fun figuring out what works best...I
love doing this sort of thing.

Steve


I've got the ANC-4 unit now and will be experimenting with it over the
weekend. I'll use a variety of wire antennas of different lengths and
configurations. My first impression is positive. I've attached it to
short wires and sure enough, the noise floor goes way down.
Interestingly enough, though, I find that it will not work at all in
conjunction with the H-800 active whip. I'll try it again at some
point, but the whip is nowhere near as effective as a wire, at least in
my preliminary tests

Steve