[TowerTalk] Some MFJ-259B Notes versus expectations

LYN designserv@ipass.net
Thu, 12 Nov 1998 12:53:29 -0500

>From N6CR original posting:

> W8JI continues:
> >Don't rely on the frequency counter in this unit. It was not a design
> >focal point. It is what I call a "sorta feature".
> >If you want a frequency counter for use with two meter rigs, buy a
> >"real" frequency counter rated in a few parts per million. This one
> >has only .05% accuracy since it uses the microprocessor's time base to
> >determine the gate time. If you weed through these units looking for
> >an accuracy of more than .001% (plus or minus 1.5 kHz on 150 MHz) you
> >spend a lifetime looking. And when you find it, it will remain that
> >accurate only for a short while.

N6CR reply:

> Interesting.  My 259 was extremely accurate and remained so.  Other
> very inexpensive counters from Optoelectronics and Ramsey seem to be
> fairly accurate, as are the synthesizers in very inexpensive amateur
> and consumer electronic equipment.  Would you accept any transciever
> that was wrong by 6 to 100KHz (and more) and could not be calibrated?
> My assumption was that the 259B would be an improvement over the older
> model, not a step backward. If the frequency determining ability of the
> unit is this bad, the rest of the modes are certainly questionable as
> well.  In addition, no specification is given by MFJ anywhere for what
> the user can expect for accuracy...there is NO calibration standard.
> Don't include a "sorta feature" if the units can't tell the difference
> between 146.000 and 145.990.  Or at least tell the buyer how bad the
> unit really is.

I agree with Tom in that I think purchasers who look for this unit tobe
useful in matters beyond published specifications or beyond
reasonable expectations for the class of equipment are being
unrealistic.  I would never expect to use an swr analyzer of this
low price range to be useful for high-accuracy frequency
measurements.  If the manufacturer gave no spec on the
performance in this area, then a reasonable purchaser could
expect only enough performance to be useful in its category,
perhaps a little better or worse depending on the unit price
as compared to other equipment in the same category.

I agree with Rick, however, that it is reasonable to expect
the manufacturer's quality control to catch production
defects before the equipment is shipped.

Lyn, W4WDN

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