[TenTec] TT Amplifier Connections 101

[Carl Moreschi]

The old Omni A/D/B/C rigs just had an amplifier key line that came up when
you keyed the radio and then stayed up after keying for a variable time that
you could set with an internal pot.  This is roughly equivalent to the EXT
T/R line in the Pegasus, Jupiter, and Orion.  But the old Omni rigs used a
relay for this that made a noticeable click that most people didn't like.
The newer radios with their EXT T/R line just use a transistor so there is
no audible click.

The TXEN and TXOUT lines were added with the later Corsairs, the Omni V,
Paragon's, Pegasus, Jupiter, and Orion.  These lines provide timing to use a
QSK amplifier.  When you key these radios, they bring up TXOUT.  The TXOUT
line then goes to the amplifier's key line.  When the amplifier's antenna
relay switches over, the amplifier then brings up a key out line.  You
connect this line back to TXEN.  When the radio sees TXEN come active, the
radio actually then begins to transmit.  This guarantees clean QSK
switching.

Carl Moreschi N4PY
Franklinton, NC
----- Original Message ----- 
From: "John Pfeifer" <jpfeifer at gci.net>
To: <tentec at contesting.com>
Sent: Tuesday, May 03, 2005 1:43 PM
Subject: [TenTec] TT Amplifier Connections 101


> Could someone out there who has experience with the lineage of Ten Tec
rigs
> give me an overview of the various methods used to key Ten Tec amplifiers
as
> the rigs have evolved?
>
> >From past reading of the group I know that sometime during the run of the
> Corsair II, they changed from KEY/KEYER OUT to TX EN/TX OUT setup they use
> today.  As I understand it, with the KEY/KEYER OUT method you keyed the
> amplifier first, which then keyed the rig.
>
> How did the Omni A/D/B/C series handle amplifier keying?  I assume they
had a
> different setup and seem to recall reading something about an amp keying
> relay...
>
> I've read that a early-run Corsair can be modified to use the TX EN/TX OUT
> method.
>
> Can the Omni A/D/B/C also be modified in this fashion?
>
> Thanks & 73,
> John Pfeifer - KL0WN
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