Richard,
It was ten years ago that this subject came up and which I used as a basis
for
parallel circuit antennas versus series type antennas. It also led to the
use of
circuitry analysis (complex circuitry) to provide for lossless feed systems
and
cluster coupled antennas.
All of the above was ridiculed by the experts over the years because of my
use of element coupling terminology, such that what it
pertained to was never taken seriously and sometimes mocked.
What is more frausterating to me is that many commercial antennas still
pursue
gain to the extent that low impedance occurs and where the purchaser is
forced
to purchase loss generating matching systems which robs him of some of the
purchased gain. Force1 even notes in their literature that manufactures are
supplying
poor matching impedances in the search of financial competitive gain
YOU are the first expert on this newsgroup to take a step back and pursued
a
rethink of this subject and supplied your findings in a posting.
Possibly some will now subject you to ridicule or,
if your enunciation of Terman is convincing enough, will say they knew it
all the
time but preferred to pursue harassement.
I thank you from the bottom of my heart for your courage shown in your last
posting
and hopefully, others will build on, or pursue the implications/contents of
your posting.
Best regards
Art KB9MZ Xg

"Richard Harrison" wrote in message
...
I wrote:
"Critical coupling is defined as maximum energy transfer at the resonant
frequency."

Also:
"Coupling additions (more loads) to a feedpoint lowers the impedance
unless additional measures (transformations) are taken."

I`ve since consulted Terman, and critical coupling is defined as I said
above. Terman adds coupled elements differently than I did above.

On page 64 of his 1955 edition, Terman defines critical coupling as:
"These trends continue as the coefficient of coupling is increased until
the coupling is such that the resistance which the secondary circuit
couples into the primary at resonance is equal to the primary
resistance. This is called the CRITICAL COUPLING and causes the
secondary current to have the maximum value it can attain."

On page 65, Terman`s statement supports Art:
"When the coupled impedance is added to the self-impedance of the
primary circuit, the effect at resonance is to increase the effective
primary resistance above the value that would exist in the absence of
the secondary. This causes the primary current at resonance to be
reduced in all cases by the presence of the secondary."

I wrongly assumed a coupled load would add to the primary current. I
apologize to Art and to others who I misled.

Best regards, Richard Harrison, KB5WZI