[Amps] pulse tuning

Jim Thomson jim.thom at telus.net
Mon Sep 20 02:27:31 PDT 2010


With cw dots you are "pulse" tuning at 30% duty.
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Last time I checked, CW dits are one unit length duration, and the 
spaces between dits within a character are also one unit length. Most 
keyer's   these days can have the "weight" adjusted, so that the proportion 
is not necessarily exactly what I have said. However the "standard" 
timing of a string of dits would result in 50% duty cycle.

##  On the yaesu mk-v... u can adjust EITHER the dots or dashes  from
1-129 in the menu.  Default is  dots  are 10  and dashes  are 30.  
IE: dots are X... and dashes are  3X.    IF sending a string of dots, duty cycle is 
exactly   50% [measured].   I usually use 10 and 36  for norm
cw use.   [ X   and  3.6 X]

## however, for pulse tuning an amp... I drop the  10  down to 4-7.... and 
the dots are really short duration.  I can get the duty cycle as low as  I think
8%.   Normally, I set if for aprx a 30% duty cycle.   50% is too high, unless you
are into really heavy  RF  processing on ssb mode. 

##  8%  duty cycle, although it works, is too low.  ideally, you want to use a duty
cycle thats the eq of the mode you intend to use  [like norm cw or ssb].  If it's too low, the
B+  will not drop much, resulting in higher pep out readings on a  pep meter. [ and also
on an average reading meter].  

##  50% works good too.  Now, if you really want to load down the HV supply, you can
increase the  duty cycle to well above 50%...like  60-90%. 

Jim  VE7RF





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