[TenTec] QSK w/amplifier

[Rick, NJ0IP / DJ0IP]

Hi Wayne,

Jerry described the problems you can get.
I used the Ten-Tec 405 amp with my Argonaut for many years.
It too was carrier-triggered.
I didn't like that.  So I changed it.

Inside the Argonaut you will find two lines called "R" and "T".  If I recall
correctly (it was 25 years ago that I did this), these lines go high when
active, to about 8 volts (?) - R when in RX mode or T when in TX mode.  I
tapped into the T-line and keyed a transistor which in turn was used to key
the 405 Amp's relay.  I also had to make some slight changes to the 405, but
it was easy.  I documented the changes, but unfortunately all of my gear and
manuals is currently packed in shipping boxes in preparation for my move to
the states later this month, so it will probably be months before I find
that old manual.

If you really want to do it right, you need a little external box and you
attach the keyer to it.  When you key it with your keyer, it keys the amp
through a transistor (you'll need the mod in the amp I spoke of above) and
about 10ms later it keys the Argonaut's key jack.  It also has an adjustable
delay that enables you to manually control how long the amp's relay remains
keyed after the last dit or dah has come.

I can send you a full description of this keying circuit, but unfortunately
it is in German language.  However you can see the schematic and the timing
diagrams.  Given enough time, I can also translate it into English, but I
won't have time for that until I have finished all of my packing here.

I have used this little box (which also has a home brew C-MOS keyer in the
same box) for almost 30 years now.  It is a great box to have for matching
almost any amp to any transceiver.  Yes, it also keys the higher negative
voltage keying lines of older amps.

73
Rick, 
DJ0IP (NJ0IP)

On Tue, 2007-04-03 at 21:49 -0500, Wayne Whitman wrote:
> I also sent an email to THP, here is there (very quick) response for
> anyone who was wondering.
> 
> "It is not designed to
> be QSK- compatible but may follow slow semi break-in QSO
> with Rf sensed keying circuit.
> It has some rise time and fall time that means amp holds
> for a second or so after you stop keying."
> 
> Guess that rules that one out.
> 
> Thanks for reading and thinking about it.
> 
> 73,
> Wayne
> K4ELO
> 
> tentec