I stand by my position that when the source is an RF power amplifier,
and when all the available power is transferred from the source to the
load, the source impedance is the conjugate of the load impedance. In
a similar instance, if the load is a pure resistance, the source
resistance equals the load resistance.

And referring to a statement Dysart made concerning plate resistance,
Rp, it must be understood that in Class AB, B and C amplifiers, Rp is
NOT the source resistance. In those amplifiers the effect of Rp is a
negative feedback that reduces the effect of plate-current change
resulting from a change in grid voltage, thus reducing the power
output compared to what the output would be if Rp were absent.
Compensation for the power lost to Rp is accomplished by simply
increasing the grid drive.

Consequently, Rp plays no part in achieving a conjugate match at the
junction of the network-output and the load. Although lossless
elements are required to achieve a perfect conjugate match in both
directions, a perfect conjugate match is obtained in the forward
direction with real elements when all available power is being
delivered to the load. This condition is verified in data presented in
Chapter 24 of Reflections 3.

Walt, W2DU