[TenTec] CW non-QSK/PTT keying

Jim Reid jimr.reid at verizon.net
Sat Dec 27 12:47:00 EST 2003


It was written:

> >> I've not seen one, perhaps they are out there,
> >> but a little external box to handle key sequencing....

Ameritron has had such a gadget out for a few years:
their QSK-5 product.  I have one here and have used it
with my former OmniVI+ and Henry amplifiers.

The QSK transmitting function works wonderfully;  however,
the unit uses both relays and power PIN diodes to accomplish
the various required switch functions.  While the xmit
side continues to operate without difficulty,  the rcv side
relays tend to get dirty or something and this leads to
severe attenuation of rcv signals!  I thought my Omni
was going deaf;  then discovered a few taps on the key
would bring back rcv.  However,  rcv eventually completely
failed in spite of my attempts to operate on the unit to
clean several relay contacts.  The offending contacts
seem difficult,  if not impossible to reach to "clean";
buried to the inside of a "stack" of mechanism.  Also
there appears to be a "sealed" relay unit which may
actually be the offending part.  Anyway,  I have
stopped using the QSK-5,  and it now sits on a shelf
in a near by closet.

Seems it would be pretty simple to fix up my own
line to the Henry amplifier PTT jack.  All that is 
required is a contact to gnd. Wouldn't that satisfy
users who want CW transmit only when a PTT foot
pedal were actuated?  That would take care of the
T/R in and out relays within the amplifier and
the antenna switching between rcv and xmit.
Receiver goes deaf when the foot pedal is actuated 
with this set up as the linear amp components
are now "in line".

This solution does NOT provide QSK operation,
only solves the T/R and potential hot switching
problem so long as you key the PTT with your
foot pedal BEFORE keying the exciter.  If you didn't
push the pedal in time,  and were keying the rig already
when you actuated the foot pedal.....oops, that probably
would cause hot switching -- so this is not a "fool" 
proof solution.

In fact,  maybe a disaster waiting to occur in a hot
and heavy contest situation.  BTW,  I also have a
contesting wooden plaque here on the wall,  1st
place,  Oceana,  one of the WRTC events; worked
them all,  both modes,  hi.

73,  Jim  KH7M





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