[MFJ-Ameritron] MFJ analyzers

Tue, 22 Jan 2002 10:34:56 -0500

> The 269 has a 259 with some mods plus a plug in uhf board. The MFJ
> group has had major problems getting the boards to talk to each other.
> Go for a 259b and get a separate unit for UHF that is what I did.

The bulk of the problems with the 269 appear to be assembly line 
related problems. The failure rate (which counts untils not working 
when they are shipped) is around 4%, which is too high. 

What MFJ needs more than any single thing is a dedicated QC 
person who does nothing but move through the place looking at 
what people are doing.   

The boards really don't talk to each other. The detectors and tripler 
are on the separate board from a mother board because of physical 
room and the necessity to have the N connector be in the physical 
center of the detector bridge system.

The bulk of assembly problems center around the ribbon cable 
soldering, one of the few things people have to solder in this unit.

The 269 uses 12 bits in the processing of the A/D signals. The 259 
is eight bits. The 269 has better resolution when reading reactance 
and resistance because the 259 can only resolve about 0.4% 
voltage change at the detectors.

The overall accuracy isn't much different, but the annoying jump in 
display reactance for a one-bit change in detector voltage is 
reduced. 

> 
> 
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Eric Lemmon
> Sent: Monday, January 21, 2002 9:37 PM To:
> [email protected]; [email protected] Subject: Re:
> [MFJ-Ameritron] MFJ analyzers
> 
> 
> Percy,
> 
> I would steer clear of the MFJ-269.  I am on my second unit, and it is
> going back for another exchange.  The first unit would not enter the
> UHF mode at all, and the counter was off by about 4 MHz.  MFJ sent me
> a new replacement unit which worked fine for about nine months, then
> would not switch out of UHF no matter what I did with the switches! 
> I've been trying for weeks the reach someone at the tech support line,
> but always get a busy signal.  I have sent three e-mails over the past
> several months, but got no reply.
> 
> Although perhaps half of the MFJ products I have bought were returned
> within a few months for replacement, the half that I kept are still
> working well.  My MFJ-434 Voice Keyer has worked flawlessly through a
> 36-hour special event with every operator using it.  On the other
> hand, the MFJ-1270C TNC I just received was found to have a defective
> PROM- only some of the commands worked.
> 
> You get what you pay for, and you can't get ham at hot dog prices. 
> Pass on the MFJ-269, and buy an AEA 140-525 Analyst.  I did- and now I
> wish I had not spent money on the 269!
> 
> 73, Eric Lemmon WB6FLY
> 
> Percy Mistry wrote:
> 
> > Hi, would anyone be able to tell me what exactly is the difference
> > (technically) between the MFJ-249B and MFJ-259B ?
> >
> > Also, apart from the extended UHF range, what is the difference
> > between MFJ-269 and the others mentioned above ? Is there is a
> > differnce in accuracy, reliability etc... ?
> >
> > Thanks,
> > 73,
> > Percy KC0GVT.
> >
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73, Tom W8JI
[email protected] 