[Amps] Input relay for QSK amp

Jim Thomson jim.thom at telus.net
Sun Dec 9 14:54:03 EST 2018


Date: Sun, 9 Dec 2018 08:22:45 -0700
From: Jim Garland <4cx250b at miamioh.edu>
To: Bob Maser <bob.maser at gmail.com>, jimw7ry at gmail.com
Cc: amps at contesting.com
Subject: Re: [Amps] Input relay for QSK amp

<Jim, You're right in principle, of course. The problem is that a 
<well-designed amplifier relay circuit shouldn't depend on what 
<transceiver is used. The amplifier itself should be immune to 
<hot-switching in all situations.

<Jim W8ZR

##  Ok, what happens on VOX  SSB ??   Some xcvrs output  RF
a lot faster than  others.   And the  0-30 msecs  delay adjustment on my
yaesu  FT-1000-MP  MK-V  only works on CW  mode. 

##  One fellow on another forum mentioned that his  new yaesu  FTDX-3000 
when run on VOX  SSB, has a tendency  to  fry the relay contacts on his  L4B
and L7 amps, which are  3PDT mech types, with  15 msec operate time.  His
conclusion is the 3000  xcvr outputs RF on ssb  vox, a lot quicker than any of his
other xcvrs.   The only  fix is faster TR relays in the amps  with  3 pdt  relays. 

Jim   VE7RF



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