Which Noise Cancelling Antenna Would You Choose ?
RHF
Which Noise Cancelling Antenna Would You Choose ?
Timewave [JPS] ANC-4 RF Noise Canceller
http://www.universal-radio.com/catalog/filters/0094.html
http://www.timewave.com/support/ANC-4/anc4.html
MFJ-1025/1026 Noise Cancelling Enhancers
http://www.universal-radio.com/catalog/preamps/3541.html
http://www.mfjenterprises.com/Product.php?productid=MFJ-1025
http://www.mfjenterprises.com/Product.php?productid=MFJ-1026
Why 'Choose' One Noise Cancelling Antenna over the other ?
Do You Use One of these Two Noise Cancelling Antennas ?
Do You Like the Noise Cancelling Antenna ?
Do You Get the ResuLts You Wanted with the Noise Cancelling Antenna ?
Would You Buy a Noise Cancelling Antenna again ?
Have You Tried a Noise Cancelling Antenna and Don't Like It ?
i want to know - iane ~ RHF
.
mi...@sushi.com
> FO&A,
>
> Which Noise Cancelling Antenna Would You Choose ?
>
> Timewave [JPS] ANC-4 RF Noise Cancellerhttp://www.universal-radio.com/catalog/filters/0094.htmlhttp://www.timewave.com/support/ANC-4/anc4.html
>
>
> Why 'Choose' One Noise Cancelling Antenna over the other ?
>
> Do You Use One of these Two Noise Cancelling Antennas ?
>
> Do You Like the Noise Cancelling Antenna ?
>
> Do You Get the ResuLts You Wanted with the Noise Cancelling Antenna ?
>
> Would You Buy a Noise Cancelling Antenna again ?
>
> Have You Tried a Noise Cancelling Antenna and Don't Like It ?
>
> i want to know - iane ~ RHF
> .
I have the ANC-4 from back in the day (JPS). It workes with my long
wire. I can't get it to work with the Wellbrook though others have
claimed to do so.
RHF
> On Jan 6, 8:07 pm, RHF <rhf-newsgro...@pacbell.net> wrote:
>
>
>
>
>
> > FO&A,
>
> > Which Noise Cancelling Antenna Would You Choose ?
>
>
> > MFJ-1025/1026 Noise Cancelling Enhancershttp://www.universal-radio.com/catalog/preamps/3541.htmlhttp://www.mf...
>
> > Why 'Choose' One Noise Cancelling Antenna over the other ?
>
> > Do You Use One of these Two Noise Cancelling Antennas ?
>
> > Do You Like the Noise Cancelling Antenna ?
>
> > Do You Get the ResuLts You Wanted with the Noise Cancelling Antenna ?
>
> > Would You Buy a Noise Cancelling Antenna again ?
>
> > Have You Tried a Noise Cancelling Antenna and Don't Like It ?
>
> > i want to know - iane ~ RHF
> > .
>
> I have the ANC-4 from back in the day (JPS). It workes with my long
> wire. I can't get it to work with the Wellbrook though others have
>
> - Show quoted text -
M...Sushi,
My use/application would be with an Inverted "L" Antenna; plus
a Snake {Coax Cable} 15 Foot Vertical Antenna located outside
as the Noise {Sense} Antenna.
~ RHF
.
Steve
I have the Timewave unit and like it very much. I use it with a
Wellbrook ALA-330S, using an active whip as the 'sense antenna'. It's
made a big difference for me and I've never regretted buying it.
I've never used the MFJ unit so I can't comment on its effectiveness.
David
>> [D]iane ~ RHF
> .
You forgot the mother of all noise canceler antennas, Alfalfa:
Steve
> FO&A,
>
> Which Noise Cancelling Antenna Would You Choose ?
>
> Timewave [JPS] ANC-4 RF Noise Cancellerhttp://www.universal-radio.com/catalog/filters/0094.htmlhttp://www.timewave.com/support/ANC-4/anc4.html
>
>
> Why 'Choose' One Noise Cancelling Antenna over the other ?
>
> Do You Use One of these Two Noise Cancelling Antennas ?
>
> Do You Like the Noise Cancelling Antenna ?
>
> Do You Get the ResuLts You Wanted with the Noise Cancelling Antenna ?
>
> Would You Buy a Noise Cancelling Antenna again ?
>
> Have You Tried a Noise Cancelling Antenna and Don't Like It ?
>
> i want to know - iane ~ RHF
> .
And of course there's the new phasing unit from DX Engineering, if you
have a lot of dough in your pocket:
RHF
> On Jan 6, 11:07 pm, RHF <rhf-newsgro...@pacbell.net> wrote:
>
>
>
>
>
> > FO&A,
>
> > Which Noise Cancelling Antenna Would You Choose ?
>
>
> > MFJ-1025/1026 Noise Cancelling Enhancershttp://www.universal-radio.com/catalog/preamps/3541.htmlhttp://www.mf...
>
> > Why 'Choose' One Noise Cancelling Antenna over the other ?
>
> > Do You Use One of these Two Noise Cancelling Antennas ?
>
> > Do You Like the Noise Cancelling Antenna ?
>
> > Do You Get the ResuLts You Wanted with the Noise Cancelling Antenna ?
>
> > Would You Buy a Noise Cancelling Antenna again ?
>
> > Have You Tried a Noise Cancelling Antenna and Don't Like It ?
>
> > i want to know - iane ~ RHF
> > .
>
- if you have a lot of dough in your pocket:
-
- http://www.dxengineering.com/Products.asp?ID={6F07CEB4-27D0-4664-A2AA-352A69ED88CD}&SecID=114&DeptID=12
-
Steve - Yes that would be the DX Engineering Model # NCC-1
http://www.dxengineering.com/Products.asp?ID=215&SecID=114&DeptID=12
P/N : DXE-NCC-1 - Noise Canceling Controller @ $495 +S&H
http://www.dxengineering.com/ProductDetail.asp?ID=215&SecID=114&DeptID=12
The NCC-1 "Noise Canceling Controller" is a Two-Channel
Receiving Antenna Phasing System. - http://tinyurl.com/oms63
http://www.dxengineering.com/Parts.asp?ID=1227&PLID=215&SecID=114&DeptID=12&PartNo=DXE%2DNCC%2D1
Currently my Noise Cancelling needs do not exceed the $495
price tag of the NCC-1 "Noise Canceling Controller". ~ RHF
.
RHF
-a Wellbrook ALA-330S, using an active whip as the 'sense
- antenna'. It's made a big difference for me and I've never
- regretted buying it.
-
- I've never used the MFJ unit so I can't comment on its
- effectiveness.
Addition Thoughts and Comments :
One of the things that I like about the MFJ-1025/1026
Noise Cancelling Antenna {Phasers} is the fact that they
have a SO-239 Jack for the Auxiliary {Noise} Antenna.
http://www.universal-radio.com/catalog/preamps/3542rear.html
MFJ-1025/1026 Noise Cancelling Enhancers
http://www.universal-radio.com/catalog/preamps/3541.html
http://www.mfjenterprises.com/Product.php?productid=MFJ-1025
http://www.mfjenterprises.com/Product.php?productid=MFJ-1026
While the Timewave [JPS] ANC-4 RF Noise Canceller
uses an RCA Jack for the Noise Antenna [J1]
http://www.universal-radio.com/catalog/preamps/0094dia.html
Timewave [JPS] ANC-4 RF Noise Canceller
http://www.universal-radio.com/catalog/filters/0094.html
http://www.timewave.com/support/ANC-4/anc4.html
I plan on using a 15 Foot Vertical 'Snake' Antenna made
out of a single piece of Coax Cable for the Noise {Sense}
Antenna with the Noise Cancelling Combiner/Phaser.
I want this Noise {Sense} Antenna about 25 away from
the House to pick-up the local outside Noise.
http://groups.google.com/group/rec.radio.shortwave/msg/e30c9dfd1a8b21a2
http://groups.google.com/group/rec.radio.shortwave/msg/4f0482421d02e624
15 Feet Vertical Noise {Sense} Antenna
o
l
l
l
l
l
F=====================================P-
'o' =End Insulator for Rigging Rope
'l' = 15 Foot Vertical Antenna Element using the
Center Conductor and Insulator of the Coax Cable.
'F' = Snap-On Ferrite Bead placed where the
Antenna Element begins.
'=' = 35+ Feet of Coax Cable feed-in-line
'P-' = PL-359 Plug to connect to the Noise Cancelling
Combiner/Phaser.
FWIW - I understand that the MFJ-1025 without the little
built-in Whip {Noise} Antenna is preferred over
the MFJ-1025 that has the little built-in Whip {Noise} Antenna.
~ RHF
.
Steve
>
> While the Timewave [JPS] ANC-4 RF Noise Canceller
> uses an RCA Jack for the Noise Antenna [J1]http://www.universal-radio.com/catalog/preamps/0094dia.html
>
>
> I plan on using a 15 Foot Vertical 'Snake' Antenna made
> out of a single piece of Coax Cable for the Noise {Sense}
> Antenna with the Noise Cancelling Combiner/Phaser.
> I want this Noise {Sense} Antenna about 25 away from
>
> 15 Feet Vertical Noise {Sense} Antenna
> o
> l
> l
> l
> l
> l
> F=====================================P-
> 'o' =End Insulator for Rigging Rope
> 'l' = 15 Foot Vertical Antenna Element using the
> Center Conductor and Insulator of the Coax Cable.
> 'F' = Snap-On Ferrite Bead placed where the
> Antenna Element begins.
> '=' = 35+ Feet of Coax Cable feed-in-line
> 'P-' = PL-359 Plug to connect to the Noise Cancelling
> Combiner/Phaser.
>
> FWIW - I understand that the MFJ-1025 without the little
> built-in Whip {Noise} Antenna is preferred over
> the MFJ-1025 that has the little built-in Whip {Noise} Antenna.
>
> ~ RHF
>
> - Show quoted text -
I suggest that you keep an open mind about what serves as your noise
antenna. You might find that the coax antenna described above is just
the ticket. However, I hope you'll at least try a few different kinds
of antennas, or a few different configurations/lengths of your wire
antenna, to see what works best most of the time. You might be
surprised!
RHF
>
> > While the Timewave [JPS] ANC-4 RF Noise Canceller
> > uses an RCA Jack for the Noise Antenna [J1]http://www.universal-radio.com/catalog/preamps/0094dia.html
>
>
> > I plan on using a 15 Foot Vertical 'Snake' Antenna made
> > out of a single piece of Coax Cable for the Noise {Sense}
> > Antenna with the Noise Cancelling Combiner/Phaser.
> > I want this Noise {Sense} Antenna about 25 away from
>
> > 15 Feet Vertical Noise {Sense} Antenna
> > o
> > l
> > l
> > l
> > l
> > l
> > F=====================================P-
> > 'o' =End Insulator for Rigging Rope
> > 'l' = 15 Foot Vertical Antenna Element using the
> > Center Conductor and Insulator of the Coax Cable.
> > 'F' = Snap-On Ferrite Bead placed where the
> > Antenna Element begins.
> > '=' = 35+ Feet of Coax Cable feed-in-line
> > 'P-' = PL-359 Plug to connect to the Noise Cancelling
> > Combiner/Phaser.
>
> > FWIW - I understand that the MFJ-1025 without the little
> > built-in Whip {Noise} Antenna is preferred over
> > the MFJ-1025 that has the little built-in Whip {Noise} Antenna.
>
> > ~ RHF
> > .- Hide quoted text -
>
> > - Show quoted text -
- I suggest that you keep an open mind about what serves
- described above is just the ticket. However, I hope you'll at
- least try a few different kinds of antennas, or a few different
- configurations/lengths of your wire antenna, to see what
- works best most of the time. You might be surprised!
-
Steve - That is all very true.
Three Different Noise "Sense" Antennas To Use For
Noise Cancelling Antennas With An Antenna Phaser.
Noise "Sense" Antenna # 1 - Short Vertical Antenna :
The short 15 Foot Vertical Antenna is a good 'starting-point' :
Since a Vertical Antenna should 'Sense' equally in all
directions {omni-directional} from all noise sources that
surround it.
Both the MFJ and Timewave-JPS Boxes have a Noise Antenna
"Gain" Adjustment so hopefully 15 Feet will be in the useful
Range of this Gain Control. Otherwise, I will have to shorten
it down to 5 Feet and try again. But, if I do shorten it down to
5 Feet : I still want the Top-End to be at about 15 Feet above
the surface of the ground; meaning that part of the Coax Cable
will also be part of the Vertical-Up-Leg.
Noise "Sense" Antenna # 1S - Shorter Vertical Antenna
Five Feet (5') Vertical Noise {Sense} Antenna
o - 15 Feet above the ground
l
l
F
ll
ll
ll
ll===========================P- Ground Level
'o' =End Insulator for Rigging Rope
'l' = 5 Foot Vertical Antenna Element using the Center
Conductor and Inner Insulator of the Coax Cable.
'F' = Snap-On Ferrite Bead placed where the Antenna
Element begins and the Outer-Shield Ends.
'll' and '=' = 45 Feet of Coax Cable feed-in-line
'P-' = PL-359 Plug to connect to the Noise Cancelling
Combiner/Phaser.
Noise "Sense" Antenna # 2 - Short Dipole Antenna
Beyond the 15 Foot Vertical Antenna; I have also though of
trying a Short 6-Foot Tip-to-Tip Dipole Antenna mounted on
a 10 Foot piece of PVC Pipe and directly wired to a Coax
Cable feed-in-line. Manually position the Dipole Antenna
one-time for the Best Noise Pick-up and Cancellation.
Noise "Sense" Antenna # 3 - One-Metre Loop Antenna
Next might come a single-turn One-Metre Loop Antenna;
again mounted on a 10 Foot piece of PVC Pipe and
directly Wired to a Coax Cable feed-in-line. Manually
position the Loop Antenna one-time for the Best Noise
Pick-up and Cancellation.
~ RHF
.
mi...@sushi.com
>
> While the Timewave [JPS] ANC-4 RF Noise Canceller
> uses an RCA Jack for the Noise Antenna [J1]http://www.universal-radio.com/catalog/preamps/0094dia.html
>
>
> I plan on using a 15 Foot Vertical 'Snake' Antenna made
> out of a single piece of Coax Cable for the Noise {Sense}
> Antenna with the Noise Cancelling Combiner/Phaser.
> I want this Noise {Sense} Antenna about 25 away from
>
> 15 Feet Vertical Noise {Sense} Antenna
> o
> l
> l
> l
> l
> l
> F=====================================P-
> 'o' =End Insulator for Rigging Rope
> 'l' = 15 Foot Vertical Antenna Element using the
> Center Conductor and Insulator of the Coax Cable.
> 'F' = Snap-On Ferrite Bead placed where the
> Antenna Element begins.
> '=' = 35+ Feet of Coax Cable feed-in-line
> 'P-' = PL-359 Plug to connect to the Noise Cancelling
> Combiner/Phaser.
>
> FWIW - I understand that the MFJ-1025 without the little
> built-in Whip {Noise} Antenna is preferred over
> the MFJ-1025 that has the little built-in Whip {Noise} Antenna.
>
> ~ RHF
> .
Shouldn't the noise antenna be a vertical whip?
RHF
>
> > While the Timewave [JPS] ANC-4 RF Noise Canceller
> > uses an RCA Jack for the Noise Antenna [J1]http://www.universal-radio.com/catalog/preamps/0094dia.html
>
>
> > I plan on using a 15 Foot Vertical 'Snake' Antenna made
> > out of a single piece of Coax Cable for the Noise {Sense}
> > Antenna with the Noise Cancelling Combiner/Phaser.
> > I want this Noise {Sense} Antenna about 25 away from
>
> > 15 Feet Vertical Noise {Sense} Antenna
> > o
> > l
> > l
> > l
> > l
> > l
> > F=====================================P-
> > 'o' =End Insulator for Rigging Rope
> > 'l' = 15 Foot Vertical Antenna Element using the
> > Center Conductor and Insulator of the Coax Cable.
> > 'F' = Snap-On Ferrite Bead placed where the
> > Antenna Element begins.
> > '=' = 35+ Feet of Coax Cable feed-in-line
> > 'P-' = PL-359 Plug to connect to the Noise Cancelling
> > Combiner/Phaser.
>
> > FWIW - I understand that the MFJ-1025 without the little
> > built-in Whip {Noise} Antenna is preferred over
> > the MFJ-1025 that has the little built-in Whip {Noise} Antenna.
>
> > ~ RHF
> > .
- Shouldn't the noise antenna be a vertical whip?
-
M...Sushi - Yes and No - Well May-Be-So !
Yes for a general One Whip {Vertical} Antenna "Fits" many
'possible' Noise Source Needs - When the Location and
Direction of the Noise Source is Not Known. The Whip
{Vertical} Antenna will in-fact collect all signals equally
and be very effective for most local Noise Cancelling uses.
* This would be a Two Sigma [95%] solution to the vast
majority of Home Radio Shack and/or Amateur Radio
Station needs for 'local' Noise Reduction {Cancellation}.
The Whip {Vertical} Antenna is a One-Size-Fits-All solution
for a Simple and Practical {Cost Effective} Noise Antenna
and is very easy for the End-User to use and get good results.
KISAP - Keep It Simple And Practical
When the Location and Direction of the 'local' Noise Source is
Known; or when the Noise is Severe : Then a more directional
Noise Source Antenna may be used to 'pin-point' the Source
of the Noise and Optimize the Noise Cancellation Totally and
Completely : In these cases a Dipole Antenna or Loop Antenna
can be used to better Focus in on the Noise Source and Tune
It Out; to the exclusion of other Noise Sources not in the same
direction.
* This would be a Three Sigma [99.73%] solution to the small
number of Home Radio Shack and/or Amateur Radio Station
needs for complete elimination of 'local' Noise is the objective.
The Dipole and Loop Antennas are not a One-Size-Fits-All
Solution : not simple to implement; not always practical to
use; they cost more; and are more dificult for the End-User
to use; but when done right can yield super results.
* ITALOWTGIR - It Takes A Lot Of Work To Get It Right.
Hence - Start with the Whip or Vertical Antenna and build on
your personal experience until you are satisfied with your
Noise Reduction {Cancellation} efforts to optimize your
Radio Listening and Enjoyment.
~ RHF
.
RHF
> In
> Message-ID:<4ddc5080-b6c2-46cc-a725-48f3a35dd...@c4g2000hsg.googlegroups.com>
> posted on Tue, 8 Jan 2008 23:08:08 -0800 (PST), m...@sushi.com wrote:
> Begin
>
> >Shouldn't the noise antenna be a vertical whip?
- If that's what responds best to your noise, however some power line
- carried noise such as arching hardware down the street are better
- received with a horizontal.
- One trick I use with my ANC-4 when using a long broad banded sense
- antenna is to run it through a pre-selector to leave only the noise
at
- your frequency of interest. That reduces overload issues. I have an
old
- Grove TUN-3 pre-selector from back in the 80s that I use for this.
- --
-
- 73 de
- KM6RF
- Bart
BB - That is an Interesting Idea and a Good Tip to use a
Pre-Selector between the Noise 'Sense" Antenna and the
Combiner/Phaser to better 'select' the Noise Signal to you
are trying to reduce / eliminate. - iane ~ RHF
Plus you are also right that the Noise "Sense" Antenna
should 'match' your Noise Source to achieve the best
results from your Noise Cancelling Antenna set-up.
Noise from Street side Overhead Power Line may in-fact
require a Horizontal Wire Antenna Element to get the
best reduction from such a source. The Turn-able short
Dipole Antenna or Loop Antenna may also be a better
Noise "Sense" Antenna to pick-up and eliminate this
type of locatable source of Noise.
-ps- Those old Grove TUN-3 Pre-Selectors are little gems.
.
bpnjensen
>
> Which Noise Cancelling Antenna Would You Choose ?
>
> Timewave [JPS] ANC-4 RF Noise Cancellerhttp://www.universal-radio.com/catalog/filters/0094.htmlhttp://www.timewave.com/support/ANC-4/anc4.html
>
>
> Why 'Choose' One Noise Cancelling Antenna over the other ?
>
> Do You Use One of these Two Noise Cancelling Antennas ?
>
> Do You Like the Noise Cancelling Antenna ?
>
> Do You Get the ResuLts You Wanted with the Noise Cancelling Antenna ?
>
> Would You Buy a Noise Cancelling Antenna again ?
>
> Have You Tried a Noise Cancelling Antenna and Don't Like It ?
>
> i want to know - iane ~ RHF
> .
My MFJ-1026 works very well for some kinds of noise, with two rather
dissimilar external antennas attached. It gets rid of most of the
noise that I hoped it would, that is, the continuous static and
droning kinds of things (only one noise source at a time, however).
It could probably get rid of lightining crashes and sporadic noise as
well, but in practice the knob-twiddling required takes a tiny bit too
long fo rti to be effective; ANL and NB work better for those sources.
There is some minor internal diddling that must be done, explained in
the manual, depending on your antenna configuration, but it is very
easy and quickly accomplished. Some people install a switch to
reverse the main and accessory antennas, and it is too bad that MFJ
have not simply provided one. I will probably do this on mine
eventually. There are plans for this on the web, IIRC, another very
simple mod.
This unit also attenuates MW, especially at the low end; there is a
specific component inside that can simply be crushed to eliminate this
attenuation if MW is high on your list of uses for this device. In
fact, some like it just for that reason, because it is VERY effective
at nulling strong stations so that weak ones can be heard underneath.
I have tried this on several occasions, and have been astonished at
how well it works.
I would get one again (maybe even two in tandem if two sources of
noise are annoying simultaneously), but I think for best results you
need two antennas that are very close in design. You should have
plenty of room up thar in the hills for that!
Bruce Jensen
bpnjensen
>
> While the Timewave [JPS] ANC-4 RF Noise Canceller
> uses an RCA Jack for the Noise Antenna [J1]http://www.universal-radio.com/catalog/preamps/0094dia.html
>
>
> I plan on using a 15 Foot Vertical 'Snake' Antenna made
> out of a single piece of Coax Cable for the Noise {Sense}
> Antenna with the Noise Cancelling Combiner/Phaser.
> I want this Noise {Sense} Antenna about 25 away from
>
> 15 Feet Vertical Noise {Sense} Antenna
> o
> l
> l
> l
> l
> l
> F=====================================P-
> 'o' =End Insulator for Rigging Rope
> 'l' = 15 Foot Vertical Antenna Element using the
> Center Conductor and Insulator of the Coax Cable.
> 'F' = Snap-On Ferrite Bead placed where the
> Antenna Element begins.
> '=' = 35+ Feet of Coax Cable feed-in-line
> 'P-' = PL-359 Plug to connect to the Noise Cancelling
> Combiner/Phaser.
>
> FWIW - I understand that the MFJ-1025 without the little
> built-in Whip {Noise} Antenna is preferred over
> the MFJ-1025 that has the little built-in Whip {Noise} Antenna.
>
> ~ RHF
>
> - Show quoted text -
If you remove the whip and configure the internal shunts
appropriately, the 1026 effectively becomes the 1025. Interestingly,
that little whip works quite well if no other antenna is available.
Bruce Jensen
RHF
>
> > While the Timewave [JPS] ANC-4 RF Noise Canceller
> > uses an RCA Jack for the Noise Antenna [J1]http://www.universal-radio.com/catalog/preamps/0094dia.html
>
>
> > I plan on using a 15 Foot Vertical 'Snake' Antenna made
> > out of a single piece of Coax Cable for the Noise {Sense}
> > Antenna with the Noise Cancelling Combiner/Phaser.
> > I want this Noise {Sense} Antenna about 25 away from
>
> > 15 Feet Vertical Noise {Sense} Antenna
> > o
> > l
> > l
> > l
> > l
> > l
> > F=====================================P-
> > 'o' =End Insulator for Rigging Rope
> > 'l' = 15 Foot Vertical Antenna Element using the
> > Center Conductor and Insulator of the Coax Cable.
> > 'F' = Snap-On Ferrite Bead placed where the
> > Antenna Element begins.
> > '=' = 35+ Feet of Coax Cable feed-in-line
> > 'P-' = PL-359 Plug to connect to the Noise Cancelling
> > Combiner/Phaser.
>
> > FWIW - I understand that the MFJ-1025 without the little
> > built-in Whip {Noise} Antenna is preferred over
> > the MFJ-1025 that has the little built-in Whip {Noise} Antenna.
>
> > ~ RHF
> > .- Hide quoted text -
>
> > - Show quoted text -
>
- If you remove the whip and configure the internal shunts
- Interestingly, that little whip works quite well if no other
- antenna is available.
-
- Bruce Jensen
-
BpnJ - Do you have either -or- Used Either ? ~ RHF
.
bpnjensen
> BpnJ - Do you have either -or- Used Either ? ~ RHF
As I mentioned in earlier post (did you not receive it?) I have the
1026, and it works pretty well. Here is the text:
>>My MFJ-1026 works very well for some kinds of noise, with two rather
dissimilar external antennas attached. It gets rid of most of the
noise that I hoped it would, that is, the continuous static and
droning kinds of things (only one noise source at a time, however).
It could probably get rid of lightining crashes and sporadic noise as
well, but in practice the knob-twiddling required takes a tiny bit
too
long for it to be effective; ANL and NB work better for those
sources.
There is some minor internal diddling that must be done, explained in
the manual, depending on your antenna configuration, but it is very
easy and quickly accomplished. Some people install a switch to
reverse the main and accessory antennas, and it is too bad that MFJ
have not simply provided one. I will probably do this on mine
eventually. There are plans for this on the web, IIRC, another very
simple mod.
This unit also attenuates MW, especially at the low end; there is a
specific component inside that can simply be crushed to eliminate
this
attenuation if MW is high on your list of uses for this device. In
fact, some like it just for that reason, because it is VERY effective
at nulling strong stations so that weak ones can be heard underneath.
I have tried this on several occasions, and have been astonished at
how well it works.
I would get one again (maybe even two in tandem if two sources of
noise are annoying simultaneously), but I think for best results you
need two antennas that are very close in design. You should have
plenty of room up thar in the hills for that! <<
I would add to the initial post that, the reason I think two similar
antennas would be better is because you really want each of them to
"hear" the same noise at roughly the same level and the same way. The
ability to null that noise is optimized when the noise signals are
about the same strength. Having said this, it is best also to have
the antennas separated by a fraction of wavelength of interest, which
is usually not a problem for most people.
Right now, I am using a DXUltra sloped multiband Dipole and a 45'
random wire; these two are fairly effective together, but I think that
two dipoles or two similar random wires would be even better - based
on my limited experience, I think I could get some really deep, quiet
nulls on pretty nasty noise with that setup. I just wish I only had
one noise source!
BJ
bpnjensen
Also, regarding that little whip - when I first got the device before
putting up antenna No. 2, I used the whip quite a bit, and it
amazingly did a pretty good job on 60 and 75 and 90 meters, which are
real problem bands for me. If noise nulling is all you are interested
in, rather than actually phasing antennas, then all you need for the
accessory antenna is something that will "hear" the noise, and that
little whip did fine job, at least here. It also heard the stations
pretty well, given that it has a fairly strong preamp behind it :-)
I never tried the whip as a MW station nuller.
BJ
bpnjensen
> posted on Wed, 9 Jan 2008 09:00:29 -0800 (PST), bpnjensen wrote: Begin
>
> >I would get one again (maybe even two in tandem if two sources of
> >noise are annoying simultaneously)
>
> but with 6db drop per unit, you lose all signal fairly quickly.
> --
>
> 73 de
> KM6RF
> Bart
Bart, do you know if that 6 dB loss is even with both antennas
receiving the desired signal? One would think that the *very
approximate* 3 dB gain provided by the second antenna would help
offset this loss...
Bruce Jensen
bpnjensen
> posted on Thu, 10 Jan 2008 07:03:42 -0800 (PST), bpnjensen wrote: Begin
> If there is enough signal from the sense antenna to be amplified it can
> be phase selected for to reinforce the overall output, as in an
> electronically steerable array, but for noise 'reduction' that gain is
> only used to match the inverse phased signal's re-insertion level to
> achieve a null, and the output is therefore reduced by 6db.
> --
>
> 73 de
> KM6RF
> Bart- Hide quoted text -
>
> - Show quoted text -
Yeah, I see your point now. I wonder if this value holds for the MFJ
units as well?
BJ