[TenTec] OMNI VI and fast switching amp hook up ?

[Carl Moreschi]

Hank,

Let TXOUT pick the antenna relay of your amplifier.  Then also have TXOUT
wired through an unused normally open contact of the amp antenna relay.
Then bring TXOUT back to the Omni VI TXEN line through this normally open
contact and you have everything just fine.  Now with this setup the Omni VI
cannot transmit without both TXOUT active and the amp antenna relay picked
or energized.  There is really no solid state components to fail in this
path.  You may need a diode on TXOUT so it can be used to both pick the
antenna relay and return to TXEN for isolation on this path.

This is exactly how a QSK amplifier is wired for the tentec txen txout
scheme.

Carl Moreschi N4PY
Franklinton, NC
----- Original Message ----- 
From: "Hank Phillips" <aa4hp at titustek.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Saturday, December 03, 2005 6:53 PM
Subject: Re: [TenTec] OMNI VI and fast switching amp hook up ?


> Lots of good comments on the reflector already, but I will pass along my
> observations.
>
> Getting an amplifier to close relays quickly enough is not a problem,
maybe
> even without resorting to the vacuum relay speed-up circuits.  Even
> sequencing them to close and open in the correct order is relatively easy,
> depending on the relays you have available.  All of this has been covered
> in excellent detail by Rich Measures, AG6K and others.
>
> Background:
>
> When you go key down on the Omni 6+, after some setup delay in the
> transceiver, the "TX OUT" line on J-1 goes low (to ground).  When the
> factory jumper is installed, it pulls "TN ENABLE NOT" on J-2 down and the
> transmitter goes on the air.
>
> This is important:   In my Omni 6+, if you pull "TX ENABLE NOT" down on
> J-2, no matter what the state of the operator's mind or the condition of
> the remainder of the station, the transmitter goes on the air.  This
allows
> a failure external to the transceiver to put Omni into transmit, even
> though that may not be what you had in mind.
>
> I believe the optimal solution would be for the Omni to go into transmit
if
> both J-2 and J-1 were driven low, that way only a response to the Omni
> transmit request would put the transmitter on the air.  That would require
> additional logic in the transceiver.
>
> I tried to the "Y-cable" trick, and the Omni didn't like the pull-up
> voltage on the opto-isolator I ground to key the amplifier.  You might be
> able to get around that with either an emitter-follower or FET input to
the
> amplifier that didn't confuse the existing Omni signalling.  Another
> possibility might be to pick off the collector of Q-16 and bring it out to
> an external connection, and you could still keep the TXHang
programmability.
>
> Anyway, I wimped out before solving the problem, settling out of court for
> the relatively inoffensive built-in relay.  If anyone nails this, I would
> like to hear your approach.
>
> Very 73,
>
> Hank
>
> AA4HP
>
>
> At 01:59 AM 12/1/2005 +0000, you wrote:
> >Hi-
> >  I have an OMNI VI and a TL-922a amp which I just finished wiring with
> > vacuum relays for QSK fast switching. Works great but, the OMNI relay
> > used to key non Ten Tec amps is annoying on CW. (Not real annoying
but....)
> >  Of course when not using the amp, which is 99.9% of the time I can
> > switch the relay off and have quiet CW.
> >  Is there any reason why I can't tap into the TX EN and TX OUT jumper
> > with a "Y" connection and run the quiet transistor switching to ground
> > since TX OUT does go to ground when its active and then leave the relay
OFF?
> >
> >73 de Dave in NH  K1OPQ
> >
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