On Sat, 29 May 2010 09:43:21 -0700 (PDT), walt wrote:

Apparently we have different editions of Terman.
Mine doesn't discuss R as the remnant of conjugation, so if only R is
considered in the image impedance I can concur with you on this issue.

Hi Walt,

Go to the index and look up Thévenin. The material should be found in
two areas:
1. Circuits with Lumped Constants - Thévenin's Theorem - Impedance
Matching
2. Audio Voltage Amplifiers - Resistance-coupled Amplifiers

Rp is a
non-dissipative resistance, not a resisTOR with physical
characteristics. I consider the voltage-current ratio R appearing at
the output of the tank circuit to be the source resistance of the RF
power amplifier. If you do not agree with this position then I guess
we'll just have to agree to disagree, unless you can find some way to
change my mind.

I will use your own data.

On Thu, 27 May 2010 19:32:40 -0700 (PDT), walt wrote:

In this condition the DC plate voltage is 800 v and plate
current is 260 ma. DC input power is therefore 800 v ? 0.26 a = 208 w.

I will be concerned with nothing else outside of this specification as
this is a discussion of the "real" Tube, and a power supply which will
be considered as loss-less.

First. There is one current loop throughout the entire system.

Second. Unique to a tube path within that current loop, there are two
characteristic current types. These are the convection current WITHIN
the cathode-plate interval, and the induction current that completes
the loop from plate to cathode through conventional power supply
wiring.

Third. The induction current's mobile electrons move at a rate of
meters per minute; whereas the charge mobility is near light speed.

Fourth. The convection current's mobile electrons (a literal particle
stream in a vacuum) move at a rate of near light speed. The term
"near light speed," in this case, is limited by the plate potential of
800V and can be computed; whereas the charge mobility is near light
speed, but generally higher (and specifically higher for 800V) than
the electron speed.

Fifth. It takes work to move an electron initially at rest to near
light speed over the interval between the cathode and the plate with
nanoseconds transit times.

Sixth. The electron gains kinetic energy from the field between the
plate and cathode.

Seventh. The kinetic energy of the electron is converted into heat
upon striking the plate, the heat energy being equal to the power
supply energy expended in accelerating the electron.

I will forgo the math of how considerable the resistance, power, and
heat is. All can be found from the data quoted above. Clearly, the
plate resistance is real in every sense of the word. It is the
limiting factor of the current path hence it is the source resistance
in every sense of the word.

The seven points I enumerate are from material drawn from a single
source. I am sending you the full chapter treatment that speaks to
this topic alone from:
"Physical Electronics," Curtis L. Hemenway, Richard W. Henry, Martin
Caulton; John Wiley and Sons, 1962.

Others may ask for copies of this reference. Others may ask where the
heat comes from, a topic I would enjoy elaborating upon. It is a very
simple explanation that by using Walt's data above, can be rendered
into Watts/Temperature with only the difficulty of pressing calculator
keys. These values than can weighed against real and tested
observation at the bench of the same tube in operation.

I cannot imagine anything else meriting discussion.

73's
Richard Clark, KB7QHC