[TenTec] Argonaut/Titan III

[NJ0IP]

Jim,

I fully agree with you in theory, but I don't think the Argonaut V is
designed to be keyed from an external amp.  I'm stabbing in the dark here
because I've never seen the Argonaut's V schematic.

Unless you modify the Argonaut V to do the complete handshaking like the
Omni's and Orion, etc. do, then I think it's better to key the normal
(non-tentec) input of the linear.

In any case I would use at least one transistor to isolate the Argonaut's T
line from the amp's relay circuitry.  THe reason mine had three transistors
is because two of them were already inside the model 405.  I wanted to keep
the option of keying the 405 as originally planned, with RF, and I wanted to
keep the delay which MUST be isolated from the T line.

73
Rick

-----Original Message-----
From: tentec-bounces at contesting.com
[mailto:tentec-bounces at contesting.com]On Behalf Of Jim Brown
Sent: Wednesday, July 21, 2004 5:22 AM
To: tentec at contesting.com
Subject: RE: [TenTec] Argonaut/Titan III


On Wed, 21 Jul 2004 10:11:51 -0700, NJ0IP wrote:

>I think you should tap onto the "T" signal in the Argonaut V as the signal
>to key the Amp.  I did this with an old Argonaut 509, running the 405
>amplifier.  I'm not an engineer so I "stole" ideas from other rig's
>circuits.  My keying unit ended up being 3 transistors and a 25K Ohm
>variable to addjust the delay for returning the amp to RX.

I am using the T-line to key my Hercules (original) from my Omni V,
because it is specifcally designed to be keyed by the T-line of the original
Omni-series rigs. It's a very simple mod to go inside the Omni V, find the
T-
line, and bring it out. I removed the remote speaker jack and brought the T-
line out on a BNC that fits in that hole. No relays, no transistors, just a
simple jumper from the T-line to the keying input of the Hercules.

But that is the WRONG way to key later Ten Tec amps (that is, everything
but the original Hercules, which was built in the early 80's). The right way
to
key Ten Tec amps is to key the amp directly, then let the amp key the
radio. This provides the proper delays, and is completely painless. That's
how I'm keying my Titan 425. Anything else (including what you are
suggesting) is unnecessarily complicated.

Jim Brown  K9YC




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