I have the MFJ-1026. I don't use the "useless" whip antenna" but this model
does have the built in amplifier. The gain of this amp can be set by
internal jumpers and it can be used to amplify the signal from the external
sense antenna. The amplifier can be switched in and out on the front panel.
I find the amp very useful in helping to get the right amount of injection
signal. I would recommend the 1026 model over the 1025.
Thank you for the video Anthony. How much noise attenuation are you getting.
I have easily got a 20db reduction in line noise with my MF-1026. More
reduction requires more care with the sense antenna levels I think but can
be done.
Mark N1UK
----- Original Message -----
From: "Anthony M" <anth...@consultexcel.com.au>
To: "Jerry Johnson" <jjohn...@cableone.net>; <flexradio@flex-radio.biz>
Sent: Monday, 19 October, 2009 3:27 PM
Subject: Re: [Flexradio] MFJ Noise Canceller & Flex3000 Video
The primary antenna is a 40M Loop that is up about 10-15 meters on one
side and 4 meters on the other side.
The noise antenna is a 40M dipole that runs parallel down one side of the
loop.
A word of warning however - If you're going to put your receive and tx
antenna so close to each other you may need to modify your MFJ to cope
with the copious amounts of RF it will cop. I had to (with help) Add a
relay internally that grounded the noise antenna on TX so that the rf did
not scramble the unit.. It should have been there from factory but I don't
really know what MFJ were thinking leaving it out.
In regards to the 1026 - I had option of buying both- the 1026 has a
telescopic whip built in which is useless for 99% of people as the noise
antenna must receive the noise as well as your primary antenna in order to
null one out. Your receive capability is basically determined by your
weakest antenna. The whip might be ok if you have super bad powerline
noise that's coming into your house but that's about it.
The 1025 is exactly the same unit (the board even says 1026) without the
preamp (used for the telescopic whip) and without the telescopic whip
which is kind of pointless anyways.
Its also worth noting that it really is a pain in the *** to get the noise
antenna and the tx antenna right - not to mention fiddling to get a
perfect null but it can be done. That was the point of this video - to
show that yes it CAN be done.
Cheers,
Anthony
VK3FAJM
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
--------------------------------------------------
From: "Jerry Johnson" <jjohn...@cableone.net>
Sent: Monday, October 19, 2009 11:07 PM
To: "'Anthony M'" <anth...@consultexcel.com.au>;
<flexradio@flex-radio.biz>
Subject: Re: [Flexradio] MFJ Noise Canceller & Flex3000 Video
Excellent Demo. You might comment what you are using for your primary and
secondary antennas. I found on using the MFJ1026 that the built in
antenna
did not pick up enough of the noise to cancel out. Going with an external
antenna did the trick.
73's, Jerry WB0UZW.
-----Original Message-----
From: flexradio-boun...@flex-radio.biz
[mailto:flexradio-boun...@flex-radio.biz] On Behalf Of Anthony M
Sent: Monday, October 19, 2009 4:20 AM
To: flexradio@flex-radio.biz
Subject: [Flexradio] MFJ Noise Canceller & Flex3000 Video
I have as promised created a second video showing the use of the MFJ 1025
Noise Canceller and the Flex 3000 radio.
This is part one of a multi part series which I will record showing
various
things about my setup - the next part will show adjusting the phasing
controls to attain a good null.
Hope you enjoy the video
http://www.youtube.com/watch?v=DpftxVd-jZ8
73
Anthony
VK3FAJM
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