I have a question about how the ANC-4 works. Specifically, it's about
the antennas that you connect to the ANC-4 in order to cancel noise or
make a 'phased array'.

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.

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. 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?

Thanks!

Steve

Steve wrote:
I have a question about how the ANC-4 works. Specifically, it's about
the antennas that you connect to the ANC-4 in order to cancel noise or
make a 'phased array'.

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.

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. 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?

Thanks!

Steve


Hi Steve,

You might get a better response from the folks over at
rec.radio.amateur.antenna

I have eight antennas combined in 7 ANC-4's.

If you use the two serious antenna approach, you simply steer a null
onto the noise source. Unless the desired signal is in the same
direction, it's not cancelled.

Depending on the separation and orientation of the array, it may even
be enhanced (in a peak of the pattern of the phased pair) while the
noise is eliminated (in a null of the pattern of the phased pair).

Generally a quarter wave of separation is good, giving you a peak
at one endfire while you have a null at the other endfire. In general
the null will be a V pattern that you sweep from one endfire, opening
up at broadside to a line, and closing at the other endfire, as you
tune the phasing and gain.

And more generally than noise sources, you can cancel out a local
broadcaster and listen to what's under it, by steering your null onto
him, though it can be a tricky adjustment, since you need an insanely
deep null, so you're dealing in fractions of a degree.

--
Ron Hardin


On the internet, nobody knows you're a jerk.

On Thu, 31 Aug 2006 01:32:40 GMT, Ron Hardin
wrote:

I have eight antennas combined in 7 ANC-4's.

If you use the two serious antenna approach, you simply steer a null
onto the noise source. Unless the desired signal is in the same
direction, it's not cancelled.

Depending on the separation and orientation of the array, it may even
be enhanced (in a peak of the pattern of the phased pair) while the
noise is eliminated (in a null of the pattern of the phased pair).

Generally a quarter wave of separation is good, giving you a peak
at one endfire while you have a null at the other endfire. In general
the null will be a V pattern that you sweep from one endfire, opening
up at broadside to a line, and closing at the other endfire, as you
tune the phasing and gain.

And more generally than noise sources, you can cancel out a local
broadcaster and listen to what's under it, by steering your null onto
him, though it can be a tricky adjustment, since you need an insanely
deep null, so you're dealing in fractions of a degree.


You should point out your antennas are active verticals of the Dymek
DA-100E type. It's not possible to steer an array of random wires
with any precision.

http://www.universal-radio.com/CATALOG/sw_ant/0328.html

David wrote:
You should point out your antennas are active verticals of the Dymek
DA-100E type. It's not possible to steer an array of random wires
with any precision.

http://www.universal-radio.com/CATALOG/sw_ant/0328.html

It doesn't matter. Precision doesn't come into it any more or less
with random wires.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

On Thu, 31 Aug 2006 08:27:40 GMT, Ron Hardin
wrote:



It doesn't matter. Precision doesn't come into it any more or less
with random wires.

A random wire is already full of nulls and nodes. Much easier to
phase vertical omnis.

In article ,
"A. Pismo Clam" wrote:

Steve wrote:
I have a question about how the ANC-4 works. Specifically, it's about
the antennas that you connect to the ANC-4 in order to cancel noise or
make a 'phased array'.

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.

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. 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?

Thanks!

Steve


Hi Steve,

You might get a better response from the folks over at
rec.radio.amateur.antenna

I would not recommend rec.radio.amateur.antenna to anybody for any
reason.

--
Telamon
Ventura, California

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.

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. 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?

A noise bridge works by subtracting the noise from the signal. (The
adjustments work by making the time delay, the polarity, and the amplitude
of the noise antenna signal to be the same as the noise coming in on the
main antenna so it can be subtracted). Thus forming an antenna that,
electrically, looks like the difference between the two antennas. So,
to work, you need two antennas that receive the noise and desired signals
in different ratios.

Say, you have a main antenna that picks up signal and noise, and you
have a noise antenna that picks up 10 times as much noise as the
signal. After you adjust your noise bridge to match the amplitude,
the desired signal on the noise channel is only one tenth that on the
main antenna, and that's all you'll lose.

You can get this different noise-to-desired ratio by either putting the
noise antenna as close as possible to the source, or using a directional
antenna. As I remember another poster there, (Ron Hardin?), it often
works better to use a loop to null out the desired signal and just get
the noise and then use the ANC-4 to combine that with another antenna.

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

Steve wrote:
I have a question about how the ANC-4 works. Specifically, it's about
the antennas that you connect to the ANC-4 in order to cancel noise or
make a 'phased array'.

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.

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. 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?

Thanks!

Steve

By this time I've used the ANC-4 enough to know that it's a big help.
Where noise is concerned, it makes much more of a difference for me
than running off batteries, ferrite cores, etc. I'm kicking myself for
not getting one of these sooner. I find that my noise floor usually
drops one or two S-units the instant I turn the ANC-4 on. Adjusting the
controls then can make a huge difference; and at my location it almost
always makes more of a difference than is necessary to compensate for
the 6 dB insertion loss. It especially shines during the day on LSB and
USB.

I've tried it with a lot of different antennas, but I'll be
experimenting with antennas for quite some time, I suspect. I did
eventually get good results using the H-800 active whip. However, where
noise reduction is concerned, I find that I get the best results using
a wire antenna that snakes its way between my house and the neighbor's
house and then back near some power lines. The nulls with the wire
antenna are just as deep as they are with the H-800, but they're a lot
easier to find. These conclusions are pretty tentative, though, as I am
still experimenting and trying out different arrangements.

On the whole, I think the ANC-4 is great and worth every penny if you
have problems with noise. It works as advertised.

Steve

Steve = tks 4 that, a very informative and interesting post.

I want to ask the group this:
I had a MFJ-1026 noise canceller when I lived in suburban Joburg.
I tried every sort of antenna combination - verticals, horizontals, whips
and Windom's, but the thing never abated the noise to any appreciable
extent, so I gave up on it after a year of fiddling and experimenting.

Now I have passed it on to a friend who lives in a very noisy suburb of Cape
Town. He did no better than me with it and also gave up on it. Now he has a
Wellbrook ALA1530 which gives him decent results.

So my question is this:
Is the Timewave ANC-4 markedly superior to the MFJ1026?

--
John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Braun T1000, Sangean 818 & 803A.
GE circa 50's radiogram
Antenna's RF Systems DX 1 Pro, Datong AD-270
Kiwa MW Loop
http://www.dxing.info/about/dxers/plimmer.dx

"Steve" wrote in message
oups.com...
By this time I've used the ANC-4 enough to know that it's a big help.
Where noise is concerned, it makes much more of a difference for me
than running off batteries, ferrite cores, etc. I'm kicking myself for
not getting one of these sooner. I find that my noise floor usually
drops one or two S-units the instant I turn the ANC-4 on. Adjusting the
controls then can make a huge difference; and at my location it almost
always makes more of a difference than is necessary to compensate for
the 6 dB insertion loss. It especially shines during the day on LSB and
USB.

I've tried it with a lot of different antennas, but I'll be
experimenting with antennas for quite some time, I suspect. I did
eventually get good results using the H-800 active whip. However, where
noise reduction is concerned, I find that I get the best results using
a wire antenna that snakes its way between my house and the neighbor's
house and then back near some power lines. The nulls with the wire
antenna are just as deep as they are with the H-800, but they're a lot
easier to find. These conclusions are pretty tentative, though, as I am
still experimenting and trying out different arrangements.

On the whole, I think the ANC-4 is great and worth every penny if you
have problems with noise. It works as advertised.

Steve