Noise reduction boxes
 

In the beginning, long long ago, there was a guy living on the Isle of Man
who designed a noise reduction box that worked by using a small sense
antenna to pick up more noise than signal and phasing it to cancel the noise
coming in on the "real" antenna.

This was reverse engineered by Doug DeMaw, who wound up making a little PC
Board to do this job and selling a few of them. Coming into the present
century, MFJ made a similar package and marketed it, but apparently no
longer does. (Or else they hide it in their catalog very well).

If anyone can tell me their part number of that unit, I'd be forever
indebted, and would venture forth and try to locate one to give to a friend
in Wales who is currently suffering the demise of his top band operation due
to local interference. Better yet, if anyone reading this has one that
they'd like to part with for money, I'd like to be introduced.

Regards
W4ZCB

Noise reduction boxes
 

Harold E. Johnson wrote:
In the beginning, long long ago, there was a guy living on the Isle of Man
who designed a noise reduction box that worked by using a small sense
antenna to pick up more noise than signal and phasing it to cancel the noise
coming in on the "real" antenna.

This was reverse engineered by Doug DeMaw, who wound up making a little PC
Board to do this job and selling a few of them. Coming into the present
century, MFJ made a similar package and marketed it, but apparently no
longer does. (Or else they hide it in their catalog very well).

If anyone can tell me their part number of that unit, I'd be forever
indebted, and would venture forth and try to locate one to give to a friend
in Wales who is currently suffering the demise of his top band operation due
to local interference. Better yet, if anyone reading this has one that
they'd like to part with for money, I'd like to be introduced.

Regards
W4ZCB



Here's an MFJ version,
http://www.mfjenterprises.com/Produc...uctid=MFJ-1026

I have a Timewave ANC-4,
http://www.timewave.com/support/ANC-4/anc4.html

I don't know how the two compare but I'm satisfied with the ANC-4, it
doesn't completely null the noise but it makes a big difference in how
well I can copy. I use a 20' piece of wire for the sense antenna.


Good luck to your friend, best wishes to you,
Galen, W8LNA

Noise reduction boxes
 

There is also the: JPS ANC-4 Noise Canceller
http://www.jps.com/downloads/support/anc4man.pdf
gwatts wrote:

Harold E. Johnson wrote:

In the beginning, long long ago, there was a guy living on the Isle
of Man who designed a noise reduction box that worked by using a
small sense antenna to pick up more noise than signal and phasing it
to cancel the noise coming in on the "real" antenna.

This was reverse engineered by Doug DeMaw, who wound up making a
little PC Board to do this job and selling a few of them. Coming into
the present century, MFJ made a similar package and marketed it, but
apparently no longer does. (Or else they hide it in their catalog
very well).

If anyone can tell me their part number of that unit, I'd be forever
indebted, and would venture forth and try to locate one to give to a
friend in Wales who is currently suffering the demise of his top band
operation due to local interference. Better yet, if anyone reading
this has one that they'd like to part with for money, I'd like to be
introduced.

Regards
W4ZCB


Here's an MFJ version,
http://www.mfjenterprises.com/Produc...uctid=MFJ-1026

I have a Timewave ANC-4,
http://www.timewave.com/support/ANC-4/anc4.html

I don't know how the two compare but I'm satisfied with the ANC-4, it
doesn't completely null the noise but it makes a big difference in how
well I can copy. I use a 20' piece of wire for the sense antenna.


Good luck to your friend, best wishes to you,
Galen, W8LNA


--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

Noise reduction boxes
 

On Thu, 17 Jan 2008 21:52:02 GMT, "Harold E. Johnson"
wrote:

In the beginning, long long ago, there was a guy living on the Isle of Man
who designed a noise reduction box that worked by using a small sense
antenna to pick up more noise than signal and phasing it to cancel the noise
coming in on the "real" antenna.

This was reverse engineered by Doug DeMaw, who wound up making a little PC
Board to do this job and selling a few of them. Coming into the present
century, MFJ made a similar package and marketed it, but apparently no
longer does. (Or else they hide it in their catalog very well).

If anyone can tell me their part number of that unit, I'd be forever
indebted, and would venture forth and try to locate one to give to a friend
in Wales who is currently suffering the demise of his top band operation due
to local interference. Better yet, if anyone reading this has one that
they'd like to part with for money, I'd like to be introduced.

Regards
W4ZCB



you didn't say what freqs you wanted it for ........... the JPS ANC-4
works between 500 khz to 80 mhz.

I 've used several of these from time to time and they work only "
somewhat " OK. when tuned to eliminate severe noise , they will
reduce or clip the signal as well. I think you will feel they are a
bit pricy for what they deliver .........

http://cgi.ebay.com/ws/eBayISAPI.dll...m=250206796968


just my experience with these ...........

Noise reduction boxes
 

**THE-RFI-EMI-GUY** wrote:
There is also the: JPS ANC-4 Noise Canceller
http://www.jps.com/downloads/support/anc4man.pdf
gwatts wrote:
....
I have a Timewave ANC-4,
http://www.timewave.com/support/ANC-4/anc4.html

They're the same, from
http://www.universal-radio.com/catal...amps/0094.html
'The ANC-4 was originally developed by JPS, but is now being
manufactured exclusively by Timewave.'

I got mine on eBay.

Noise reduction boxes
 

If anyone can tell me their part number of that unit, I'd be forever
indebted, and would venture forth and try to locate one to give to a
friend
in Wales who is currently suffering the demise of his top band operation
due
to local interference. Better yet, if anyone reading this has one that
they'd like to part with for money, I'd like to be introduced.

Regards
W4ZCB



you didn't say what freqs you wanted it for ........... the JPS ANC-4
works between 500 khz to 80 mhz.

I 've used several of these from time to time and they work only "
somewhat " OK. when tuned to eliminate severe noise , they will
reduce or clip the signal as well. I think you will feel they are a
bit pricy for what they deliver .........

http://cgi.ebay.com/ws/eBayISAPI.dll...m=250206796968


just my experience with these ...........

Well, "Top Band" is usually considered to be 1.8-2.0 MHz . I too have used
them before, (Made one of DeMaws) and for the need will work just fine.

Tnx the URL.

W4ZCB