Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

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)

Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

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.

Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

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.

Question about the Timewave ANC-4
 

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.

Question about the Timewave ANC-4
 

David wrote:

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.

No, if one antenna isn't hearing the signal you want to eliminate, the
job is done for you. If it is hearing it, you phase it away with the
other antenna.

Nothing in the operation changes. You diddle the knobs the same way
in either case, and respond the same way.

The ANC-4 doesn't care where the signal comes from, just that it's
present.

--
Ron Hardin


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

Question about the Timewave ANC-4
 

On Thu, 31 Aug 2006 15:02:46 GMT, Ron Hardin
wrote:

David wrote:

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.

No, if one antenna isn't hearing the signal you want to eliminate, the
job is done for you. If it is hearing it, you phase it away with the
other antenna.

Nothing in the operation changes. You diddle the knobs the same way
in either case, and respond the same way.

The ANC-4 doesn't care where the signal comes from, just that it's
present.

Very imprecise and technically minimalist.

Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

Bob Dobbs EC42 wrote:

On Thu, 31 Aug 2006 13:30:49 -0400, dxAce wrote:

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

And is a lot simpler device,
usually a wideband noise source (a diode abused until it hisses)
and a calibrated bridge to indicate impedence or sometimes SWR.
Generally cost about a third of an ANC-4

I used an MFJ-202B and a Drake MN-75 tuner. If I were to go back to using a
large dipole or inverted V that's probaby the combo I would again employ.

It was easy to set up the antenna for various bands and I simply marked the
basic settings on a card which made it very handy to hop from band to band.

dxAce
Michigan
USA

Question about the Timewave ANC-4
 

www.devilfinder.com Tavis Swiley's boobs

I have to watch the Waterworld movie on Radio tv Bravo channel now,and
the movie comes on Radio tv again at 9:00 PM this evening.I like the
part where that old guy is checkin the oil level and that fire comes
blazing in and he says,Oh,Thank GOD!
cuhulin

Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

David wrote:
On Thu, 31 Aug 2006 15:02:46 GMT, Ron Hardin
wrote:

David wrote:

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.

No, if one antenna isn't hearing the signal you want to eliminate, the
job is done for you. If it is hearing it, you phase it away with the
other antenna.

Nothing in the operation changes. You diddle the knobs the same way
in either case, and respond the same way.

The ANC-4 doesn't care where the signal comes from, just that it's
present.

Very imprecise and technically minimalist.

Yes, but it's also correct. I have the MFJ equivalent, and the
contraption works just as Ron describes. I have two antennas up thar,
one a random wire and the other a multiband dipole, and except for the
lower HF bands, where the random wire just isn't quite long enough, I
can cancel out most any *single* obnoxious local noise. For the MW
station nulling, by and large it works fine, despite the mismatched
antenna length...it will chew a big bite out of a pretty big local
signal and leave the weaker station 'neath intact.

It doesn't work worth a hoot for general band noise (no surprise), and
for things like distant lightning that theoretically should be
nullable, it is so tricky that it isn't really worth the trouble.

Bruce Jensen

Question about the Timewave ANC-4
 

Bob Dobbs EC42 wrote:
On Thu, 31 Aug 2006 15:06:17 -0700, bpnjensen wrote:

It doesn't work worth a hoot for general band noise (no surprise), and
for things like distant lightning that theoretically should be nullable,
it is so tricky that it isn't really worth the trouble.

That's because the DX noise is coming from the same direction as the
desired signal so there's not enough parallax to work with.
BTW: Lightening is usually impusle rather than plasma noise
and your blanker should deal with that.

Bingo on both counts. The NB does a decent job on the lightning, but
on the R75, it is not quite as broad in its powers as it could be. Not
bad, but not perfect. Luckily, or maybe unfortunately, lightning isn't
*usually* the worst noise I have to deal with at this QTH.

Bruce Jensen

Question about the Timewave ANC-4
 

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)

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

Question about the Timewave ANC-4
 

There's no trouble with active antennas, in fact they're handier because you can
get exactly the location you want when you construct your phased array of two.

What's most likely is that you're nowhere near the right gain to make the signal
you want to cancel the same strength in both antennas, and so you get no indication
of a null direction.

The ANC-4 has linear gain pots, which unfortunately means that the phase control
also changes the gain (strong at the ends, weak in the middle), which makes
searches for the null harder than it has to be.

A technique called successive overrelaxation is the most successful in searching
for a null.

Say, step the phase, and at each step minimize the S-meter with the gain, but going
a little past the minimum each time (choose a direction for this and stick to it).

Go back to the best phase, and repeat with smaller steps. Hairline changes will
be necessary at the end.

And finally notice that there's a phase button, and searching with the opposite
phase might surprise you. Having the wrong hi-lo frequency setting also changes
things, giving you less than a complete phase control.

Successive overrelaxation works when the search controls aren't orthogonal, which is
what most of the time happens.

--
Ron Hardin


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

Question about the Timewave ANC-4
 

Bob Dobbs EC42 wrote:

On Sat, 02 Sep 2006 10:47:49 +0000, Ron Hardin wrote:

The ANC-4 has linear gain pots, which unfortunately means that the phase
control also changes the gain (strong at the ends, weak in the middle),
which makes searches for the null harder than it has to be.

This statement in addition to being an internally contradicting paradox,
is inapplicable to the ANC-4's operation.
Your description "(strong at the ends, weak in the middle)"
is anything but linear. Plus the phasing isn't linked to the gain,
therefore two separate pots.

No, linear pots are linear in voltage, and you want linear in power, which they are
not.

The result is that the gain is small with the phase centered, and big with the
phase at either end.

Question about the Timewave ANC-4
 

Bob Dobbs EC42 wrote:
A technique called successive overrelaxation is the most successful in
searching for a null.

Are you suggesting some 'play' in the null seek process?

No, it's simple geometry.

Draw a long narrow ridge running SW to NE on a piece of paper. A line will do.

Now imagine that the middle of your line segment is the actual null sought.

Suppose gain moves you N-S, and phase moves you E-W.

Start S of the SW end of your line. Move N to the best null, then E to the best
null, then N to the best null, the E to the best null, etc.

You observe you follow a zigzag path making no progress up the ridge to the true
null to speak of.

Now do the same thing going _past_ the best null. Your progress is swift towards
the true null.

Successive overrelaxation goes a fixed fraction past the best null each time.

It is unnecessary where the ridge is instead a nice circle, for two steps take you
to the true null. But a long narrow ridge is very common, and SOR is the way to
find the null then.

--
Ron Hardin


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

Question about the Timewave ANC-4
 

There is no such thing as time.time does not exist.
cuhulin

Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

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

Question about the Timewave ANC-4
 

Steve 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

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

I have the ANC-4 (original JPS version), which was a great help with
random wire antennas. It seems to be of no use with my welbrook. I
tried to use the built-in noise antenna on the ANC-4 to make a null
with my Wellbrook and never managed to get that to work. Of course,
the Wellbrook is a very quiet antenna in the first place.

Question about the Timewave ANC-4
 

Question about the Timewave ANC-4
 

Ron Hardin wrote:
wrote:
I have the ANC-4 (original JPS version), which was a great help with
random wire antennas. It seems to be of no use with my welbrook. I
tried to use the built-in noise antenna on the ANC-4 to make a null
with my Wellbrook and never managed to get that to work. Of course,
the Wellbrook is a very quiet antenna in the first place.

It works fine with mine, using a wellbrook ala1530 and an active whip
(or another wellbrook 1530).

I don't think the built-in noise antenna is likely to work though.
I tossed mine out.

OK. I'll try an active whip. Still, I think the built in noise antenna
should work. It was fine when I was cancelling local computer noise.

With a wellbrook loop and a whip _located right near it_ (near means
fraction of a wavelength), you get the same pattern as with two
whips separated by a quarter wavelength, but without using any
real estate, laid out in the plane of the loop, ie. a double null
at one endfire and a max at the other endfire, opening up to a V
and sweeping to a double null at the opposite endfire and max at the
other.

Two loops separated by a quarter wavelength are handy for some things,
like nulling in advance a particular station, and then nulling another
altogether with the ANC-4, without having to go to multiple ANC-4's.

There is an odd thing with two loops, though.

For nulling a station by phasing, paradoxically, you should put the
station near the max of the loop, not the null. The phase of the
signal from the loop gets more and more unstable as you approach the
loop's null, and harder and harder to phase out with the ANC-4, is
the reason. It's comparatively easy near the loop's max.

--
Ron Hardin


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

Question about the Timewave ANC-4
 

John Plimmer wrote:
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,

Was your 1026 modified for use below 2 MHz? Mine was modified several
years ago and it worked much better in the mediumwaves after the
modification.

JB

Question about the Timewave ANC-4
 

Bob Dobbs EC42 wrote:
On Sun, 03 Sep 2006 19:37:31 +0200, John Plimmer wrote:

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

I have a local HAM friend that swears by his MFJ-1026, even though he's
never had the ANC-4, OTOH I swear by my ANC-4 never having has the 1026.
I've not even seen the MFJ-1026 unit to see if my prejudice against MFJ is
justified or not.


I've owned an ANC-4 and still own a modified 1026. I've found the 1026
to be better at killing noise and nulling out stations. That being said,
I've found the Quantum Phaser to be better than the 1026.

JB

Question about the Timewave ANC-4
 

Yes, it was MW modified and we even took it on DXpeditions and tried it for
phasing and nulls with the beverage antenna's, but results were not worth
all the knob twiddling, that's why we gave up on it.

don't get me wrong - it did work, that is it was not non-functional, just we
did not get the good results that others report.
--
John Plimmer, Montagu, Western Cape Province, South Africa

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

John,

John Barnard wrote:
Was your 1026 modified for use below 2 MHz? Mine was modified several
years ago and it worked much better in the mediumwaves after the
modification.

JB

Question about the Timewave ANC-4
 

John Plimmer wrote:
Yes, it was MW modified and we even took it on DXpeditions and tried it for
phasing and nulls with the beverage antenna's, but results were not worth
all the knob twiddling, that's why we gave up on it.

don't get me wrong - it did work, that is it was not non-functional, just we
did not get the good results that others report.

Maybe it is a QC issue with MFJ? They seem to be notorious for somewhat
unreliable and variable QC.

John Barnard

Question about the Timewave ANC-4
 

John Barnard wrote:
John Plimmer wrote:
Yes, it was MW modified and we even took it on DXpeditions and tried it for
phasing and nulls with the beverage antenna's, but results were not worth
all the knob twiddling, that's why we gave up on it.

don't get me wrong - it did work, that is it was not non-functional, just we
did not get the good results that others report.

Maybe it is a QC issue with MFJ? They seem to be notorious for somewhat
unreliable and variable QC.

John Barnard

Could be - my own MFJ-1026 chops out the offending stations really
well. If I were a MW aficionado, I'd take it everywhere.

Bruce Jensen

Question about the Timewave ANC-4
 

Ron Hardin wrote:
wrote:
I have the ANC-4 (original JPS version), which was a great help with
random wire antennas. It seems to be of no use with my welbrook. I
tried to use the built-in noise antenna on the ANC-4 to make a null
with my Wellbrook and never managed to get that to work. Of course,
the Wellbrook is a very quiet antenna in the first place.

It works fine with mine, using a wellbrook ala1530 and an active whip
(or another wellbrook 1530).

I don't think the built-in noise antenna is likely to work though.
I tossed mine out.

With a wellbrook loop and a whip _located right near it_ (near means
fraction of a wavelength), you get the same pattern as with two
whips separated by a quarter wavelength, but without using any
real estate, laid out in the plane of the loop, ie. a double null
at one endfire and a max at the other endfire, opening up to a V
and sweeping to a double null at the opposite endfire and max at the
other.

Two loops separated by a quarter wavelength are handy for some things,
like nulling in advance a particular station, and then nulling another
altogether with the ANC-4, without having to go to multiple ANC-4's.

There is an odd thing with two loops, though.

For nulling a station by phasing, paradoxically, you should put the
station near the max of the loop, not the null. The phase of the
signal from the loop gets more and more unstable as you approach the
loop's null, and harder and harder to phase out with the ANC-4, is
the reason. It's comparatively easy near the loop's max.

--
Ron Hardin


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

I've been experimenting some more with the ANC-4 / H-800 combination. I
now have the H-800 situated in a nice spot outdoors, and have noticed
something odd when it comes to eliminating noise. As soon as I turn on
the ANC-4, using the H-800 as the noise antenna, the noise is often
already minimized. For example, the noise level might immediately drop
from S6 to S3, and adjusting the noise gain and noise phase controls
will have little effect (good or bad) on this S3 noise level. This
doesn't happen everytime, but it happens a lot...most of the time.

If I then use a wire as my noise antenna, the noise level might drop
one or two S units as soon as I turn the ANC-4 on, but it takes some
knob twiddling to get the noise level down to the S3 reading that I get
automatically and immediately when using the H-800. And the best result
using the wire is always the *same* as the result I get straight away
using the H-800. Always.

I've puzzled over why this is. I think it must have something to do
with the fact that the H-800 has quite a bit more gain than the wire,
making it a better 'match' for the main antenna...which means a lot of
the work is done for me? This is just a guess.

Question about the Timewave ANC-4
 

Start by getting the reception equal in the two antennas.

The gain on the noise antenna should be set so that the main antenna
with the noise antenna disconnected (or unpowered, if active) is the
same S meter reading as the noise antenna with the main antenna
disconnected (or unpowered, if active).

You have to shade that to compensate for the phase control increasing
the gain at either extreme setting, but at least you start in the
right ballpark.

That the loop is itself directional introduces a complication. What
you want equal is the signal you're trying to eliminate, in both
antennas.

It can happen that the signal is already nulled in the loop, in which
case the loop can't help in nulling the signal in the other antenna.
Either reorient the loop or listen with the loop alone, in this case.
--
Ron Hardin


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

Question about the Timewave ANC-4
 

Bob Dobbs EC42 wrote:
On Wed, 06 Sep 2006 17:45:13 -0700, Steve wrote:

've been experimenting some more with the ANC-4 / H-800 combination. I
now have the H-800 situated in a nice spot outdoors, and have noticed
something odd when it comes to eliminating noise. As soon as I turn on
the ANC-4, using the H-800 as the noise antenna, the noise is often
already minimized. For example, the noise level might immediately drop
from S6 to S3, and adjusting the noise gain and noise phase controls
will have little effect (good or bad) on this S3 noise level. This
doesn't happen everytime, but it happens a lot...most of the time.

If I then use a wire as my noise antenna, the noise level might drop one
or two S units as soon as I turn the ANC-4 on, but it takes some knob
twiddling to get the noise level down to the S3 reading that I get
automatically and immediately when using the H-800. And the best result
using the wire is always the *same* as the result I get straight away
using the H-800. Always.

I've puzzled over why this is. I think it must have something to do with
the fact that the H-800 has quite a bit more gain than the wire, making
it a better 'match' for the main antenna...which means a lot of the work
is done for me? This is just a guess.

You'll have to evaluate which provides the better NR;
the reduction from the loops null,
or the null from the inverse phasing.
If the loop is alredady nulling the noise source then it might not be
providing adequate noise signal to the ANC-4 for its inversion process,
in which case you might try peaking the loops noise signal.


--

Echo Charlie 42
San Diego, California

I don't think the problem is due to the orientation of the loop because
we're talking about something that happens all the time and not just in
relation to one or two particular signals. I'm just about convinced
that the H-800 is simply providing more signal than the ANC-4 can
handle. I haven't tried any form of attenuation yet, but am thinking
about how to arrange that.

Steve

Question about the Timewave ANC-4
 

In article . com,
"Steve" wrote:

Bob Dobbs EC42 wrote:
On Wed, 06 Sep 2006 17:45:13 -0700, Steve wrote:

've been experimenting some more with the ANC-4 / H-800 combination. I
now have the H-800 situated in a nice spot outdoors, and have noticed
something odd when it comes to eliminating noise. As soon as I turn on
the ANC-4, using the H-800 as the noise antenna, the noise is often
already minimized. For example, the noise level might immediately drop
from S6 to S3, and adjusting the noise gain and noise phase controls
will have little effect (good or bad) on this S3 noise level. This
doesn't happen everytime, but it happens a lot...most of the time.

If I then use a wire as my noise antenna, the noise level might drop one
or two S units as soon as I turn the ANC-4 on, but it takes some knob
twiddling to get the noise level down to the S3 reading that I get
automatically and immediately when using the H-800. And the best result
using the wire is always the *same* as the result I get straight away
using the H-800. Always.

I've puzzled over why this is. I think it must have something to do with
the fact that the H-800 has quite a bit more gain than the wire, making
it a better 'match' for the main antenna...which means a lot of the work
is done for me? This is just a guess.

You'll have to evaluate which provides the better NR;
the reduction from the loops null,
or the null from the inverse phasing.
If the loop is alredady nulling the noise source then it might not be
providing adequate noise signal to the ANC-4 for its inversion process,
in which case you might try peaking the loops noise signal.


--

Echo Charlie 42
San Diego, California

I don't think the problem is due to the orientation of the loop because
we're talking about something that happens all the time and not just in
relation to one or two particular signals. I'm just about convinced
that the H-800 is simply providing more signal than the ANC-4 can
handle. I haven't tried any form of attenuation yet, but am thinking
about how to arrange that.

You can build an attenuator of any value with three resistors in a metal
box with two appropriate connectors.

--
Telamon
Ventura, California

Question about the Timewave ANC-4
 

Just swap the noise and main antennas

--
Ron Hardin


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

Question about the Timewave ANC-4
 

Ron Hardin wrote:
Just swap the noise and main antennas

Hey, Ron, does the ANC model provide a switch to accomplish this? The
MFJ does not, and that's my main gripe about that unit (I am going to
install a switch one of these days...)

Thanks,
Bruce
******

Question about the Timewave ANC-4
 

bpnjensen wrote:

Ron Hardin wrote:
Just swap the noise and main antennas

Hey, Ron, does the ANC model provide a switch to accomplish this? The
MFJ does not, and that's my main gripe about that unit (I am going to
install a switch one of these days...)

Thanks,
Bruce
******No, and worse, the connectors differ. That's why you need a box
full of adapters around the house.

--
Ron Hardin


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

Question about the Timewave ANC-4
 

Bob Dobbs EC42 wrote:
On Wed, 06 Sep 2006 20:13:21 +0000, John Barnard wrote:

Maybe it is a QC issue with MFJ? They seem to be notorious for somewhat
unreliable and variable QC.

That QC notoriety is so predictably reinforced that I choose to never
repeat my experiences with it. This includes the products of the newly
acquired Ameritron division too.



I currently have 5 different MFJ products and cannot claim any fault
on any of those items; they all do what they are supposed and do it
well. I did have an MFJ analogue audio processor which I sold when I
picked up a MFJ DSP unit. My overall experience has been positive but I
have certainly read enough to realize that there are problems with MFJ.

Thanks for the heads up on the Ameritron acquisition; I didn't notice
that MFJ acquired that company.

JB