[NLRS] More on sequencers (L O N G)

[Dr. Gerald N. Johnson]

On Mon, 2006-03-27 at 19:58 -0600, John P. Toscano wrote:
> 
> Chris Elmquist wrote:
> 
> > OK.  This is even better.  This is very close to my dream radio which has
> > a "Clear To Send" input.  With this sort of capability, you can hold off
> > the RF as long as you like while any and everything external gets to the
> > right place.  Nice.  Do you still get a PTT output from the radio that
> > goes active when any transmit function is activated?  This I would call
> > "Request To Send"...
> > 
> > So, you cause the IF radio to transmit--  it asserts "Request to Send".
> > Your sequencer now starts and begins flipping relays and keying
> > transverters, amps, etc.  The last step the sequencer does is assert
> > "Clear to Send" back to the IF rig which allows it to finally make RF.
> > 
> > And this works no matter what mode the radio is in right?  CW, VOX, FM,
> > whatever.
> 
> Chris, the idea of a "Request to Send" and a "Clear to Send" is 
> basically what Jerry was proposing by saying you need a little box 
> external to the IF radio, into which you attach the mike (and, though he 
> didn't mention it, a footswitch is a great idea also).  The PTT button 
> on the microphone (or the footswitch) becomes the "Request to Send".  It 
> goes to the sequencer, and the LAST stage of output from the sequencer 
> is the "Clear to Send" that connects back to the radio's external PTT input.
> 
The rub is that unless you go into the radio and disable the front panel
call and CW KOX and SSB/FM VOX circuits this scheme of sending mic and
key through the sequencer fail to protect if the front panel call button
is pushed. I gave up running an ARR preamp on 2m because I got tired of
replacing the GaAsFETs when I forgot to take it out of the circuit
before going to FM or CW because with the FT-726 RF appears BEFORE the
control signal.

<SNIP>
> 73 de W0JT

-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer