On Sat, 12 Jun 2010 06:13:15 -0700 (PDT), Richard Fry
wrote:

It has been theorized that a circuit consisting of a Class C vacuum-
tube r-f amplifier using a tuned tank circuit in its output network
provides an operational “non-dissipative source resistance” of 50 ohms
for energy present at the output connector of the transmitter.

However the information and measured data provided in the text
excerpts below is not very supportive of that theory.

Hi Richard,

Deja Vu all over again. I suppose you posted this to inspire me to,
once again, remind you from Mendenhall's own notes about Class C
amplifier construction - and so I will:

"It was thus necessary to determine the plate load impedance
= (Eb - Emin) / I1
~= Eb/ Idc
~= 1000 Ohms
[Not very far from Walt's determination of 1400 Ohms from his own
bench.]
"Since this was to be coupled into a Z output of 50 Ohms, a impedance
transformation of 20:1 was needed. This was accomplished by using a
voltage divider of two series capacitors to series tune the plate
circuit."

The tube is an EIMAC 4CX300A running no where near capacity.

All details (and more) written in Mendenhall's own hand.

73's
Richard Clark, KB7QHC