[600MRG] MFJ-269CM

[John Langridge]

Yeah environment/location definitely plays a huge role in its performance.  Last week while rebuilding and improving my antenna system here I had the good fortune to have access to the Rig Expert AA-600 because my modified MFJ 269B was in need of replacement detector diodes AGAIN!  The AA-600 did a great job although I do prefer the freq select knob on the MFJ to the arrow keys on the Rig Expert but I was pleased that the numbers on the AA-600 were "in the ball park" for the MFJ and both agreed with the scope match.  I'm sure the limited BW and high Q of the antenna system helps the ability to reject those out of band AM's.


Seriously, I can't imagine ever doing any development without one of these boxes.  It would be total guess work.  even trying to use the scope match alone seems like it would be a nightmare.

When I setup my previous system, I had access to a power-AIM, which was incredible.  It is reported to work without problems in close proximity to a 50kw BC and I suppose that is why it costs what it costs..

The price variation from the website to QST is interesting.  One of the things I note is that if the  $399 price is the real deal, it probably makes sense to save your pennies a little longer and just get the Rig Expert.  I'm very please with my original MFJ  but the Rig Expert is in a completely different class for sure...

73!

john XIQ



________________________________
 From: Larry <larry at w7iuv.com>
To: John Langridge <jlangridge at sbcglobal.net>; "600mrg at w7ekb.com" <600mrg at w7ekb.com> 
Sent: Thursday, July 10, 2014 5:54 PM
Subject: Re: [600MRG] MFJ-269CM
 


Took a bit to find it, but the new MFJ-259CM is listed in the web catalog at $299.95:

http://www.mfjenterprises.com/Product.php?productid=MFJ-259CM

The MFJ=269CM is also there, with no specs or data, listed at
          $399.95:

http://www.mfjenterprises.com/Product.php?productid=MFJ-269CM


I have a 259B and although I love it and wouldn't be without
          it, it is absolutely useless for low band antenna measurements
          due to QRM from AM broadcast stations. I suspect the 259CM and
          the 269CM will produce the same bogus numbers on the low bands
          as the 259B does.

Over the years I have built a dozen or so instruments for
          measureing the feedpoint impedance of large low band antennas.
          Of all of them, the classic "noise bridge" is/was the best.
          It's advantage is that it uses a selective RX for the detector.
          It's disadvantange is that it uses RX for the detector and you
          have to drag the thing out in the dirt.

These days I use a N2PK VNA. It was costly but it was worth
          every penny. It never lies and is virtually immune to BC band
          QRM if used properly.

If you use one of these MFJ instruments or any of the
          competitions similar instruments, be very cautious of the
          readings you take at the antenna.

Larry - W7IUV / WH2XGP
DN07dg - central WA
http://w7iuv.com

 

On 10-Jul-14 3:05 PM, John Langridge wrote:



Just got the August QST and page 125 is the MFJ-269C ad.  I reported in the past that MFJ originally made room for an additional series coil (holes on the board and a jumper) to get down to 472.  At Hamcom here in the Dallas area  in June, the story changed where the slug tuned inductor for the broadcast band now has enough turns remaining that it could be adjusted for 472.  ok cool... According to the ad, they now have the MFJ-269CM which is for "maritime and 600 meter coverage", operating from 470 - 940 kHz in the lowest freq position. $399.. same as the C model. So they have finally made the jump and makes you wonder what other goodies might show up in their catalog before long. 73! John XIQ
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