[AMRadio] Wilcox SSB Exciter

[Donald Chester]

From: Byron Tatum <bjtatum1 at att.net>
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? Does anyone know which Wilcox transmitter this SSB exciter operates with,
or know where I may find technical data for it? The exciter has a small tag
on the chassis top that says Wilcox SSB Exciter model 97479. The exciter is
tube-type, has 3 of 7360 tubes (plus a number of?other tubes)?and two
crystal filters: 455 KHz USB and 455 KHz LSB.?The tuned circuits (about
5)?are in plug-in cans that fit octal sockets.
??????????????? Thanks all, Byron WA5THJ

Sounds like a good quality unit. The 7360s make excellent balanced modulator
and converter stages, probably as good or better than anything else mode to
date. Also, the separate USB and LSB filters are most likely asymmetrical in
bandpass shape, with the steeper skirts on the carrier side where you really
need it, at the expense of the opposite side where it is less important. The
steeper skirt on the carrier side allows it to maintain good sideband
rejection down to a lower audio frequency than with the typical symmetrical
Hammy filter that serves for both sidebands in most amateur equipment. 

Of course, no guarantee the audio circuitry would allow any better audio
quality than a typical hammy hambone slopbucket rig, since when equipment
like that was made, space shuttle audio was the order of the day, something
which according to the prevailing propaganda of the day was to be striven
for. A few tests should show the limits of the  capability of the filters,
so that the speech amplifier circuitry, such as coupling circuitry between
stages could be modified to take full advantage of it. If it is capable of
output in the ham bands, it should be usable with about any  rig capable of
amplifying the signal to usable level without distortion.

Jerry, W4FRE has one of those Wilcox transmitters designed for aircraft
communications. Not sure the model number or whether it had provisions for a
SSB exciter. In AM  mode It doesn't sound much better than did the typical
ham SSB signals heard on the air before hams, to the chagrin of ARRL and
others, started to actually care what their SSB audio sounded like.

Don k4kyv