[Amps] pulse tuning

[Jim Thomson]

Bill, W6WRT dezrat1242 at yahoo.com 
Sat Jan 30 03:34:26 PST 2010 

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ORIGINAL MESSAGE:

On Sat, 30 Jan 2010 01:04:08 -0800, "Jim Thomson" <Jim.thom at telus.net>
wrote:

>##  I don't know why the ARRL  has this aversion to pulse tuning a GG  triode amp.

REPLY:

I can't speak for the ARRL but pulse tuning does not "sag" the power
supply enough. You could pulse tune first and then tune at full
carrier, but why bother? Just tune full carrier and be done with it.

73, Bill W6WRT
 #  say what?    On ssb, the duty cycle at most is only 30-50%.##  why  would you want to suck the B+  way down as low as it will go  with a cxr ??##  If the HV caps  are big enough,  and plate xfmr big enough,  you will easily see thatthe pep out  will be  slightly higher while pulse tuning.   Just pulse tune it... then start talking. ##  I contend, with a cxr.. you will  likely get a mis tune. .... UNLESS  you increase the loading[decrease value of load cap.. more un-meshed].. till power out drops 2%. ##  why  cook the tube /xfmr/ant/ and everything else, if  ssb is going to be used ? ##  if  rtty/fm is being used, I'd still pulse tune the amp 1st... then do the final tweak  with a  3-5 second cxr.  Jim   VE7RF