TW wrote:

Hi Scott,
The existing circuit simply uses one 1N4007 and a 1N4148 in series
thru a .01 cap to the receiver muting input (it is not THAT simple,
they are across the emitter and collector of the keying transistor; I
tried to draw it in text symbols, but gave up). What I hear in the
phones on keying is a loud "square wave" thump on each character sent.

Try putting a capacitive shunt on the line that is providing the bias
supply to the diodes, so they take a little bit of time to get up to
voltage and back down. That may slow the action up a little bit, but
it will also reduce the clicking. You may have to fiddle around with
values (and you may need a combination of a ceramic and an electrolytic
in parallel), but if the noise is caused by the rapid switching, it will
fix it.

If the noise is caused by DC offset on the output, a .1 uF ceramic in
series with the receiver input will clean that up. This might be the
case in receivers where there is a DC path through a coil winding from
antenna to ground.

I bought the Vectronics kits a couple of years ago after a period of
inactivity due to illness, mainly to get engaged and productive on
something.

I'll check out some designs in my 2000 and earlier Handbooks for relay
and/or diode switching better than the current Vectronics QSK design.
I can in fact use a vertical and a dipole, so that is a good
suggestion. Meanwhile, I enjoy QSK with my SW-20+.

After working at a military installation where the procedure was to disconnect
the UHF connector from the receiver and plug it into the transmitter between
sending and receiving, I am just glad to have anything at all.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."