[Amps] Power PEP vs drive power

[Tom W8JI]

> Why?
> 1500W out are 1500W.
> You only deduct the drive power if you want to calculate 
> gain or efficiency.

Actually drive power is fully accounted for on the front 
panel meters except for the contribution to voltage it 
causes, so the "deduct drive power" is just as bad the other 
way as not doing anything at all is.

100% of the anode current caused by drive power is accounted 
for. The only thing metering misses is the effective anode 
voltage is slightly higher than the plate volt meter 
indicates. This is because the driver voltage is pulling the 
cathode a bit negative at maximum Ip, increasing effective 
Ep but not showing it on the HV meter. Since it is a complex 
waveform the calculation isn't trivial but it amounts to 
something less than 1/2 actual drive power that isn't 
accounted for in most PA's, not the full amount as is often 
used.

The full deduction is clearly just as wrong, but the FCC 
used it to be safe.

73 Tom