Topband: ANC-4 and MFJ-1026 Comparison

[Markus Hansen]

During the last six months I have been comparing the relative effectiveness
of the ANC-4 and MFJ-1026 Noise Cancellers. I built a simple relay operated
switching circuit so I could instantly change from one unit to the other in
order to measure the difference between the two units when listening to real
live interference, ie. noise, TV birdies etc.

The results of my tests and oberservations are on my web site at:

http://www.shelbrook.com/~ve7ca/Ant160.htm

[w2pm]

Nice work and good comparisons. However I think it's important to note
that noise nulling effectiveness is subject to local conditions which
encorporate TONS of variables, and variables of variables. I have also
observed the ANC-4 to be easier to null, WHEN you can get a null and
the MFJ difficult, and frustrating, but you can often find a null after
all the work and it's deep and effective. But not always. There are
times the MFJ can't. The fixed gain of the noise input on the ANC4 I
found to be the largest problem with that unit which prevented find a
null (where the MFJ can) and the "fix" to that was an attenuator on the
noise input. WHen I did that, I often achieved a null after-all.
Sometimes as good as the MFJ, sometimes not quite as good. But then
the complexity of the tuning increased on the ANC4. Conversely, I have
found the noise level on the MFJ to be too low at times, and run a
switched noise pre-amp on it which I sometimes need to use. Consider
that I have 4 to 6 noise antennas out there in any given season
switching through each to get the best effect, regardless of the unit.

After I put in most of the 8JI mods in the MFJ, it became consistently
better than the ANC4 on 160. Not so much so on the higher bands where
the ANC4 was as-effective most of the time.

For a relatively small station here, my noise abatement systems and
"infrastructure" is quite complex. Multiple receive antennas, multiple
noise antennas, multiple noise nullers, several complex switches and
LOTS AND LOTS of cables, wires, adapters and connectors. I love it..
Keeps me off the streets.



Pete W2PM

-----Original Message-----
From: Markus Hansen <mkve7ca at gmail.com>
To: topband at contesting.com
Sent: Fri, Dec 11, 2009 6:23 pm
Subject: Topband: ANC-4 and MFJ-1026 Comparison


During the last six months I have been comparing the relative
effectiveness
of the ANC-4 and MFJ-1026 Noise Cancellers. I built a simple relay
operated
switching circuit so I could instantly change from one unit to the
other in
order to measure the difference between the two units when listening to
real
live interference, ie. noise, TV birdies etc.

The results of my tests and oberservations are on my web site at:

http://www.shelbrook.com/~ve7ca/Ant160.htm

--
Markus Hansen
VE7CA, North Vancouver, BC CANADA
Web site: http://www.shelbrook.com/~ve7ca/
_______________________________________________
160 meters is a serious band, it should be treated with respect. - TF4M

[Markus Hansen]

Hi Peter:

Thank your for response regarding the ANC-4 and MFJ-1026. You made a very
good point and something we should never over look, (I will make it clearler
on my web site) about TONS of variables. Every ham radio installation is
different from another's!. So what works for you and me may produce
different results if someone else incorporates the same set up at their
location.

And it is also important to realize that Lab testing of equipment as
important as it is, and I am an ardent believer in Lab testing, is different
than real world situations with equipment connected to real antenna's.

SP7HT, Tadek, just sent me an email regarding his experience using the
ANC-4 and I have asked him to forward it to TOBAND as it is worthwhile
information for those who use noise cancellers.

What I appreciate about the TOPBAND community is the willingness to share
their real world experiences and *experiments* regarding 160 meters, *instead
of casual observations.* Let's keep it that way!

Markus VE7CA

Markus Hansen
VE7CA, North Vancouver, BC CANADA
Web site: http://www.shelbrook.com/~ve7ca/

Post by w2pm
Nice work and good comparisons. However I think it's important to note
that noise nulling effectiveness is subject to local conditions which
encorporate TONS of variables, and variables of variables. I have also
observed the ANC-4 to be easier to null, WHEN you can get a null and the MFJ
difficult, and frustrating, but you can often find a null after all the work
and it's deep and effective. But not always. There are times the MFJ
can't. The fixed gain of the noise input on the ANC4 I found to be the
largest problem with that unit which prevented find a null (where the MFJ
can) and the "fix" to that was an attenuator on the noise input. WHen I did
that, I often achieved a null after-all. Sometimes as good as the MFJ,
sometimes not quite as good. But then the complexity of the tuning
increased on the ANC4. Conversely, I have found the noise level on the MFJ
to be too low at times, and run a switched noise pre-amp on it which I
sometimes need to use. Consider that I have 4 to 6 noise antennas out there
in any given season switching through each to get the best effect,
regardless of the unit.
After I put in most of the 8JI mods in the MFJ, it became consistently
better than the ANC4 on 160. Not so much so on the higher bands where the
ANC4 was as-effective most of the time.
For a relatively small station here, my noise abatement systems and
"infrastructure" is quite complex. Multiple receive antennas, multiple noise
antennas, multiple noise nullers, several complex switches and LOTS AND LOTS
of cables, wires, adapters and connectors. I love it.. Keeps me off the
streets.
Pete W2PM
-----Original Message-----
From: Markus Hansen <mkve7ca at gmail.com>
To: topband at contesting.com
Sent: Fri, Dec 11, 2009 6:23 pm
Subject: Topband: ANC-4 and MFJ-1026 Comparison
During the last six months I have been comparing the relative effectiveness
of the ANC-4 and MFJ-1026 Noise Cancellers. I built a simple relay operated
switching circuit so I could instantly change from one unit to the other in
order to measure the difference between the two units when listening to real
live interference, ie. noise, TV birdies etc.
http://www.shelbrook.com/~ve7ca/Ant160.htm<http://www.shelbrook.com/%7Eve7ca/Ant160.htm>
--
Markus Hansen
VE7CA, North Vancouver, BC CANADA
Web site: http://www.shelbrook.com/~ve7ca/<http://www.shelbrook.com/%7Eve7ca/>
_______________________________________________
160 meters is a serious band, it should be treated with respect. - TF4M

[Markus Hansen]

Tadek, SP7HT has asked me to share with the TOPBAND group his experience
with the ANC-4 and MFJ-1026. I quote below his email message:

"For years I am competing with local noises using ANC-4 (firstly) and
MFJ-1026 (last 10 months) for noise cancelling. I've modified the Front End
of my old ANC-4 adding a tuned resonant circuit at the Input of Noise
Channel (low impedance Input to resonant circuit, next High impedance
paralell resonance circuit using ferrite core and RX tuning capacitor I can
cover in 4 sub-bands from 1.74MHz to 30.1MHz and at the output low impedance
to connect directly to ANC-4 noise antenna Input socket).

At the Output of that modification (outside ANC-4 case) I can adjust the
level of noise signal (470 Ohm potentiometer) connected to ANC-4. So, I can
adjust NOISE GAIN in the middle position, when best cancelling can be
reached (in ANC-4).

Thanks to selective resonance circuit at the Input of Noise antenna I can
avoid intermodulation products when propagation is in a great shape (birdies
appeard every 5kHz or every 10kHz).

According to local noises in my location (a 5 floor block of flats, 19
neighbours in that house and about 300 neighbours in 100 metres circle
around my location) I can say (today) that modified ANC-4 is a better tool
to fight with local noises noises on 80CW than newest version of MFJ-1026.
73 Tadek SP7HT"

[w2pm]

Ive done something similar here by adding an MFJ 959C Preamp/Antenna
Tuner. It's a nice preamp with ability to bypass, a simple L tuner with
tunable inductance and C, a gain control for the preamp, by pass
switches for the tuner and/or preamp and 2 input switches and 2 output
switches. All for about 79 I think. In any case it's my preamp for the
Flags and Pennants as well as the noise antenna preamp for the MFJ
1025. I really don't use the ANC4 any more but occassionally will put
it out. I have noticed the tuned input helps peak the noise antenna -
very useful especially when you have a few and gives the added
flexibility for one more control to ride that noise up or down external
to the nuller. It is extra complexity and may sound silly but in a
local noise challenged suburban development, the choices are bleak. I
believe this MFJ product is rather unique on the market with all the
inputs/outputs and switching. I woudn't recommend it for contest
operation however given the limitations of the cheapie preamp circuit.

Pete W2PM

-----Original Message-----
From: Markus Hansen <mkve7ca at gmail.com>
To: topband at contesting.com
Sent: Mon, Dec 14, 2009 8:15 pm
Subject: Re: Topband: ANC-4 and MFJ-1026 Comparison


Tadek, SP7HT has asked me to share with the TOPBAND group his experience
with the ANC-4 and MFJ-1026. I quote below his email message:

"For years I am competing with local noises using ANC-4 (firstly) and
MFJ-1026 (last 10 months) for noise cancelling. I've modified the Front
End
of my old ANC-4 adding a tuned resonant circuit at the Input of Noise
Channel (low impedance Input to resonant circuit, next High impedance
paralell resonance circuit using ferrite core and RX tuning capacitor I
can
cover in 4 sub-bands from 1.74MHz to 30.1MHz and at the output low
impedance
to connect directly to ANC-4 noise antenna Input socket).

At the Output of that modification (outside ANC-4 case) I can adjust the
level of noise signal (470 Ohm potentiometer) connected to ANC-4. So, I
can
adjust NOISE GAIN in the middle position, when best cancelling can be
reached (in ANC-4).

Thanks to selective resonance circuit at the Input of Noise antenna I
can
avoid intermodulation products when propagation is in a great shape
(birdies
appeard every 5kHz or every 10kHz).

According to local noises in my location (a 5 floor block of flats, 19
neighbours in that house and about 300 neighbours in 100 metres circle
around my location) I can say (today) that modified ANC-4 is a better
tool
to fight with local noises noises on 80CW than newest version of
MFJ-1026.
73 Tadek SP7HT"



--
Markus Hansen
VE7CA, North Vancouver, BC CANADA
Web site: http://www.shelbrook.com/~ve7ca/
_______________________________________________
160 meters is a serious band, it should be treated with respect. - TF4M