Steve Nosko wrote:
"With a "conjugate match" the source dissipates 50% of the power and the
load the other 50%."

This is true only if all the source resistance is the type that converts
electrical energy to heat. There is a non-dissipative resistance.
Switched-off time in the Class-C amplifier is part of its internal
resistance.

You can deliver all the available power of the Class-C amplifier to the
load and dissipate less than 50% in the source.

Best regards, Richard Harrison, KB5WZI

"Richard Harrison" wrote in message
...
Steve Nosko wrote:
"With a "conjugate match" the source dissipates 50% of the power and the
load the other 50%."

This is true only if all the source resistance is the type that converts
electrical energy to heat. There is a non-dissipative resistance.
Switched-off time in the Class-C amplifier is part of its internal
resistance.

You can deliver all the available power of the Class-C amplifier to the
load and dissipate less than 50% in the source.

Best regards, Richard Harrison, KB5WZI


I think this becomes very academic (or perhaps a better word is awkward)
because originally you framed this as a "conjugate match" situation. Now,
you are in terms of time varying parameters. I think the analysis must stay
in one realm or the other. My mental models have trouble switching back and
forth.
I can't speak to tubes, but I do know that to get the most out of a
transistor power amp (transmitter type) up to about 200 MHz you design the
output match to be for a collector resistance of Vcc^2/(2Po). IF I recall,
this can be derived easily if you assume the transistor pulls all the way to
ground and the output tank swings up to 2 x Vcc. I was shown, and
understood it way back then, but can't recall the path to the solution off
the top of my head.
This, then, always started the discussion of whether this "matched" the
transistors output impedance or some other more esoteric concept. Then talk
of "average resistance" came in and eyes would glaze over....

The designer would then go back to the bench, work to optimize the design to
his requirements, test it over temp, etc. and ship it.

"There comes a time to shoot the Engineer and ship the product." is the
title of a famous editorial from the early 70's (IIR). Got it around here
somewhere...
-- 73
Steve N, K,9;d, c. i My email has no u's.