[Boatanchors] Hallicrafter HT 32 A PTT problem

[James M. Walker]

Sure,
Put the unit in cw mode and check the response to cw keying and fast/slow
keying. If it seems erratic also then the keying circuits around V15,16,17 
are
the area you want to check for faulty components.

I would check the VOX amplifier circuitry first, and especially the 12AX7 
and
12AT7 tubes to be sure they are good. Then check the VOX delay pot R49A
be sure of value and continuity to ground.

Remember the tube are dual apckages one half my be functional, ie; VOX amp
or anti-trip amp, both are V17.

I would check tube in that area first. FWIW

Jim
WB2FCN


----- Original Message ----- 
From: "Francis Sanita" <fsanita at cfl.rr.com>
To: <boatanchors at mailman.qth.net>
Sent: Wednesday, September 26, 2007 7:27 PM
Subject: [Boatanchors] Hallicrafter HT 32 A PTT problem


I have a HT 32A that stopped TX with PTT and would not trip in MOX.
When using a Shure 444 I need to turn the VOX adjustment all the way
up to be able to use PTT ( I do not use VOX mode). When I use a D 104
I need to turn the VOX adjustment down or the TX trips as soon as the
mic plug gets near the jack. All just stopped working.

I checked the switch assembly and cleaned all contacts of all the
switch assemblies. They all looked fine.I swapped V17 - 12AT7 - with
two other tubes and the condition remained ( by this time I was
getting sporadic PTT contact). I cleaned the contacts on the relay.
The relay made a weak - half hearted contact at times and no TX but
when it made contact it hit hard. I wiped all the tube pins and a dab
of Deox and put tubes in and out several times. Still sporadic TX on
PTT but it was getteing better. There were two plug assemblies with
wiring that all pins were
cleaned and still poor PTT TX.

I sprayed the VOX delay and adjustment pots and worked them and the
MOX worked normal and the PTT seemed to work normal and strong contact
with the Shure 444. Checked for poor grounds but the inside of the rig
is clean.

Put the chasis back in the case hooked it up and PTT and MOX started
to fail again. Turned VOX adjustment up and Shure 444 did TX but had
misses. Replaced it with the D104 and PTT works fine but MOX needs to
have operation switch to CW and then to MOX to go to TX to tune. It
does put a good signal out but I know the PTT/MOX is not working to specs.

Any similar problem or advice from Halli land??
Thank you


__._,_.___
Frank AA4FS
Palm Coast, Fl
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