[Amps] Vox ssb, time for RF to appear ?

Jim Thomson jim.thom at telus.net
Sat Oct 27 19:00:12 EDT 2018


RE:  TR relay  timing, hot switching etc.   What is  typ time, between  talking into mic on SSB VOX,
and when  RF  1st starts to even appear  at the output of the  typ  xcvr ??   On my yaesu MK-V,  on CW
mode only,  I can vary the delay between internal keyer.... and   RF appearing at the output of xcvr,
by anywhere from 0-30 msecs.... in 1 msec increments.  That adjustment allows for precise  external
amp TR relays  to get a ..head start... depending on how fast the TR relays are in the external amp. IE:
will allow  for vox  cw, when using slow open frame relays..... or sped up, faster vac relays, or pin diodes
etc, when using qsk cw. 

I see no adjustment for plane VOX  SSB.   Is this  a concern..esp with slower TR relays in an external amp ? 
I can add additional delay  via the...  TX inhibit lead, if required.   But IF the xcvrs  natural delay is say  7 msecs,
inserting 7 msecs delay into the  TX INHIBIT lead  will buy me..nothing.   Any added TX inhibit delay would have
to be longer than what is in the xcvr.   IE:  xcvr is say 7 msecs, between  coughing into mic on vox ssb,  and TX inhibit
delay  set to say 15 msecs..or longer..to match the slow TR relays in an external amp. 

I dont see any  delay specs on typ xcvrs.... when used on vox  ssb.   And I dont mean between  coughing into mic...
and  full pep output.  I mean between  coughing into mic....and  just a few watts pep  appearing at output of xcvr. 

Jim   VE7RF


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