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

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

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

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.

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.

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.

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.

Today I discovered that one of those little RF Systems mini-windom
antennas makes an awesome noise antenna for the ANC-4. It works better
in this role than any of the random wires I was using.

Steve