Ian White GM3SEK wrote:
Any device that creates those same electrical conditions possesses the
same impedance; by definition.

Sorry Ian, that's just not true. There are three separate
definitions for impedance in "The IEEE Dictionary". If all
those were the same impedance, they wouldn't need three
definitions. A resistor has a resistance. The Z0 of a
transmission line is a resistance. They are NOT the same
impedance, by definition. The IEEE Dictionary says:
"Definition (C) is a second use of "impedance" and is
independent of definitions (A) and (B)." (C) is the
definition of impedance associated with a resistor,
inductor, or capacitor. (B) is the definition of impedance
associated with a voltage to current ratio. The IEEE
Dictionary goes out of its way to explain that there is
a difference.


The transmitter affects the magnitude of the voltage and current in the
load, but it categorically does NOT affect their ratio, or the phase
angle.

Strawman

But if both kinds of load create the SAME steady-state voltage:current
ratio and phase angle at the transmitter output terminals, then by
definition they both have the SAME impedance, and the transmitter will
respond in EXACTLY the same way.

Although they may have the same value of impedance components,
they are NOT the same impedance, by IEEE definition. See above.

That principle is absolutely fundamental.

Too bad that your underlying absolutely fundamental
principle is wrong according to the IEEE Dictionary.

... because you are making
distinctions between different varieties of impedance that do not exist.

I'm just following the IEEE lead. You, OTOH, are in
logical trouble for disagreeing with the IEEE.

All valid solutions to the problem of AC/RF generators, transmission
lines and loads will most assuredly comply with the conservation of
energy! But countless textbooks show that it isn't necessary to invoke
that principle in order to make a valid analysis.

Please show me a textbook that gives you permission to
ignore the conservation of energy principle.

But WE DO enjoy the luxury of having complete information on voltages,
currents and phase angles, at any instant and at every point along a
transmission line. That allows us to obtain complete solutions without
dragging in unnecessary concepts from other disciplines.

But you guys even ignore the laws of physics for electrical
engineering, e.g. Vfor*Ifor=Pfor and Vref*Iref=Pref
--
73, Cecil http://www.w5dxp.com