[TowerTalk] MFJ 259B 6F nada

[w8ji.tom]

Hi All, 

I received about 15 e-mails on this, please excuse the single bulk reply to
all.

First things first:

> as software updates go, any manufacturer who is going to update a unit as
fast
> as MFJ seems to do with the A, B and now I hear the C, should be
facilitating
> its direct customers, and its dealers, with a method to contact recent
> purchasers, advising them how to get a free update. 

First, before we go off on a wild winge, let's get the facts. 

1.) Any 259B has the same basic features. The features may be in different
order or called different names, but they all do basically the same thing.


2.) Plain 259's, even with a mode and function button, do not have the same
features. 200 259's were
made and sold because MFJ ran out of frequency counter modules before the
software was approved, these units should say 259 on the front and box. If
you get 259 software by mistake in a unit screened 259B, you will not have
impedance related functions other than R and X and MFJ will replace the
unit. 

If you get a 259, it was SOLD only as a 259 from MFJ to the dealer or
whoever. The 259 (no B) has the features of a 259, because that is what it
really is!

2.) 6F0 and 6F1 are run numbers for components. Those numbers have
absolutely NOTHING to do with software. When the boards come in, they all
go in a big bin and you can get any board with any software. The only
difference between 6F0 and 6F1 is resizing of a few traces to aid in
surface mount soldering time. If that happens to appear with a software
revision, it is pure dumb luck.

6F is the internal code for ANYTHING to do with a 259B. The number after
the letter is the revision or run of that particular component or
subassembly. You can get a manual that says 6F2 and it ONLY means you have
the second printing with any manual revisions to date. That manual can come
with a 6F9000 circuit borad or a 6F0 circuit board and any software. The
box has a number, the knobs have a number, the paint has a number...none of
which have to agree!

Rest assured, the number on the manual HAS NOTHING to do with software,
circuit board, paint or knobs no matter what anyone else claims. The number
on the PCB has nothing to do with software or the manual either. 

3.)  Ver 2.01 and 2.02 reflect minor changes in how frequency counter
software is initilized.

4.) Expect the software to change from field feedback. For example, while
setting up my four square I had to use a scratch pad and calculator. Same
when adjusting my Beverages and a small curtain array. I've suggested
including software modes that calculate certain useful data for specific
applications. These changes might or might not be included in future
revisions.

Expect a 2.03 and on and on as time passes. NONE of the revisions to date
are due to operational flaws. (The manual has one glaring error where a cut
and paste was done, it should be corrected in 6F2) 

5.) The stability of the 259 is good enough for any antenna system I've
ever measured, including the very high Q narrow band MFJ loop antenna and
my 160 meter mobile antenna (3 kHz BW). The compromise of not providing PLL
stability is directly related to frequency range, power, and cost
issues.......not quality. It's actually more simple to do a synthesizer
than make a low current VFO function from 1.7 to 170 MHz!

> I have been following the thread about antenna analyzers and wonder if
anyone
> can shed light on how to properly check calibration, and results, of some
of
> the typically used modes of either of these products?

That's a tough one. You'd need precision RF loads of varying impedances.

>  Also am wondering if
> anyone has had a chance to compare the two on the same application?    

I don't own an AEA analyzer, I only have a multi-channel Harris Vector
Impedance meter, Wiltron network analyzer, HP Impedance test set, and brand
new HP spectrum analyzer with tracking generator option. 

I recently measured a delay line for 160 meters, and found the MFJ within
0.75 degrees of the other equipment. The MFJ was about .2 dB off on
transmission line loss on loss values between 0 and 10 dBm, and useless
measuring above 20 dB loss.

I used it to calculate the length and impedance required for a matching
stub system in my 160 and 80 meter EDZ dipole antenna, I chose 1.9 and 3.75
MHz as targets. The results were 1.910 and 3.730 MHz.

That isn't too bad, but not as good as the more expensive stuff can do when
properly used. The 259B is certainly NOT a lab instrument, but pretty
useful for Ham stuff.

73 Tom

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