[Amps] 1 db compression point procedure ?

[Jim Thomson]

Ok

What's the exact procedure for finding the ..'1db compression point'   on a HF amp ?? 

I have conflicting info on the procedure.   With hardly any drive, the typ HF amp has a 
lot of gain.    As drive levels increase, the gain goes down.   Question is.... where is the
starting point of all this??     With 1 watt of drive... or 5w or what ?   It makes a big diff
to the results. 

I'm assuming the amp is 1st tuned to  say normal power output... like 1200-1500w out..
IE: tune and load tweaked for max power out at normal power, then maybe increase the
loading a tiny bit  [ slightly more Un meshed]. 

Then leave the tune and load caps alone... and reduce drive to a very small amount... and   then measure
both the drive to the amp... and also the power output of the amp  [ say 1-5 w of drive.. and  20-100w out]
  Then start increasing drive level a bit  and  measure the gain once more  [ it should be dropping off a bit] 

Does this procedure have to be done with a cxr.. or can we do it pulse tuned ??    Have I even got the 
procedure any where near correct??  

I take it, we don't want to operate the amp beyond the point  where the gain drops by 1 db ?    But 
where is the starting point ?  

I can also tweak the bias on the GG amp quite a bit. 

tnx.... Jim   VE7RF