[Amps] Ep Sweet Spot

[sccook1 at cox.net]

It occured to me that the CW / SSB switch also changes the bias -- less ZSAC on CW.  Perhaps this is the reason efficiency changes.

Coaxial Dynamics wattmeter used to measure output 500W and input caculated based on Ep and Ip indicated on amplifier meters.

-S

---- Tom W8JI <w8ji at w8ji.com> wrote: 
> > Just curious -- does this mean that for a given tube / 
> > power level, there is a Sweet Spot where efficiency is 
> > optimal?  Or, was I seeing the effects of a tank circuit 
> > not being loaded at the design 'Q'?
> >
> > I always assumed more was better with respect to Plate 
> > Voltage (at least to a point).  But now -- I don't know...
> 
> Did you retune the tank?
> 
> Tank loaded Q has little to do with efficiency unless it 
> falls totally off the perch, or unless the tank has very 
> high loss.
> 
> My bet is you have a tuning or metering error. The only 
> other case is if something in the resonant system has 
> terrible loss.
> 
> 73 Tom
> 
>  
> 
>