John Woodgate wrote:

I read in sci.electronics.design that gwhite wrote
(in ) about '1/4 vs 1/2 wavelength
antenna', on Thu, 3 Mar 2005:
By definition, conj-match insists RL = Ri = 110 ohms. Again we are
limited in our clipping constraint by static drain current, and supply
voltage, specifically 10 V.

Our negative swing limit is, as ever, 10 V (the drain voltage).

positive swing = Id*rL = 1*55 = 55 V

This would breakdown the device, but the lower negative swing will force
us to back down the drive to meet the design defined clipping
constraint.

Pload = 10^2/(2*110) = 0.455 W

And the power dissipated in the device is also 0.445 W.

I think it is 1A*10V - 0.455 W = 9.545 W
^^^^^^ ^^^^^^^
DC input Power
Power delivered
to RL


The resistance dissipated in the "internal AC resistance" is equal to RL in the
conj-match condition. Of course, we're ignoring input power here, which is
"small" when the gain is +20 dB.

Matching
according to the 'maximum power theorem' or conjugate matching, results
in equal power in the PA and load. That's why it isn't useful for power
amplifiers.

Amusingly for my hypothetical class A conj-match example, the "equal power
dissipation" isn't such a big deal, since it is class A and the fractional power
dissipated in either the internal AC resistance or the external load resistance
is rather small compared to DC dissipation (less than 10%).

Doesn't everyone know that an audio amplifier that id designed to feed
an 8 ohm load MUST have an output source impedance of 0.0000001 ohms or
less. An output source impedance of 8 ohms would dramatically decrease
the electromagnetic damping on the loudspeaker voice-coil - by the huge
factor of .... two!(;-)

Nice one.