[CQ-Contest] Cheating - Big Amps

[Marijan Miletic, S56A]

Once upon a time Alpha made a good tube linear amplifiers but than came Acom :-)  E73M quote of 3 sentences from 8100 manual carries some hype.

If 50 W of drive is required for legal output of 1500 W, further reduced drive of 33 W (for 1.000 W output) would be even less RF-clean.  
If manufacturer is so concerned about that, 3 dB input attenuator would be appropriate for standard 100 W drive.  That is included in most solid state amps.

Ohms law defines load as ratio of voltage and current while power is the product.  Therefore power is voltage squared divided by load.
There is CW/SSB switch on some lighter tube amps which just increases plate high voltage enabling less load retuning on lower CW/RTTY power level.
Fixed HV PSU just requires higher load for reduced power.  One should always tune amplifier on maximal power intended for use in order to achieve optimal efficiency.  Retuning might be required if antenna SWR changes a lot with the frequency.  Your amplifier is just an active antenna tuner providing some gain.  This bragging is dedicated to YU7 friend who managed to cook tubes by tuning amplifier to the highest number of red plate LEDs :-( 

73 de Mario, S56A