Dick, WC1M:
The MFJ-432 is a pretty cool little box. I picked one up in 1997 for our
CQ WPX contest trip to WP3X - four out of the six stations we had set up
were using them! For laptop users, DVPs and W9XT cards are out of the
question so the '432 is a good solution.
I had problems with the unit humming in the TS-930 we were using. MFJ's
method of jumper selection for configuring the unit for Icom, Kenwood, or
Yaesu is slick, however in trying to cut corners they violated the cardinal
rule of ham xcvr mic audio: DON'T TIE THE MIC AND PTT GROUNDS TOGETHER.
They tried to re-establish some sort of isolation with some chokes, but
with the Kenwood this actually exacerabated the problem. With the Kenwood,
shorting out these chokes made the hum go away and the unit sounds very
good IMO. It also works fine with my FT-1000s. Icoms are another story -
none of my three Icoms (756, 765, 781) will work with the '432 without an
outboard Radio Shack 600:600 isolation transformer in line, then it sounds
fine.
For WP3X I whipped together a little interface with four opto-isolators
that allowed the logging program to fire the four memories of the MFJ-432.
We did not make a mod to implement the "stop" feature, rather we simply
recorded message #2 as a very short blank which would stop the playback
when #2 was selected. This was no big deal in WPX where the exchange was a
serial number, but in other contests having all four messages available
would make implementing stop worthwhile.
You might think "Gee, you're in the Caribbean, you shouldn't need a voice
keyer". Well, we were part of a multi-multi with W8MJ and I on 20M. You'd
be surprised how slow things get in mid-day on 14 MHz, even from Puerto
Rico.
73,
Dave/K8CC
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>From Larry Schimelpfenig" <lvschim@1bigred.com Fri Apr 9 18:49:50 1999
From: Larry Schimelpfenig" <lvschim@1bigred.com (Larry Schimelpfenig)
Subject: [CQ-Contest] THANKS TO ALL FOR AZTEC BALUN INFO!
Message-ID: <007f01be82b1$5e8131a0$3851efce@1bigred>
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