[Elecraft] K3: Adjusting SSB modulation for proper PEP rating

[Edward R Cole]

Since the K3 operates so differently (than traditional radios) for 
proper modulation I thought I'd ask this:
In olden days amplifiers were rated in PEP typically as 2x average 
(or CW) power, so for AM one had to set carrier at 1/4 full carrier 
output to stay linear. (1/2 carrier  for SSB).

But now I am setting up a 600w linear amp to run at P1 which is about 
0.9 of P3 (saturated power) and wondering what level of carrier power 
to run in SSB to stay linear and also not to overdrive and stress the 
expensive LDMOS device in the amplifier.

I'm running the K3 in transverter mode on 28-MHz so max output is 
1.5mw.  I can view this with a scope.  The amplifier is running at 
1296-MHz which is too high a freq to monitor with my scope.  I can 
only observe average RF power from a directional coupler and diode 
detector (like a Bird meter).

Normally, I just set power on the K3 to drive my amp to nominal full 
power and select SSB mode.  Modulation level is set by observing ALC 
meter.  I is ALC showing five bars when saying the word "five" loudly 
and six bars with compression.  So does this mean the K3 
automatically adjusts RF power in SSB to stay linear with proper 
modulation audio setting?

My reason is when running 1296 SSB to avoid overdriving the amplifier 
into P3 possibly causing harm, as much as not wanting to produce 
non-linear products.

73, Ed - KL7UW
   http://www.kl7uw.com
Dubus-NA Business mail:
   dubususa at gmail.com