Tom Donaly wrote:
Hecht was talking about two opposing waves of the same phase and
amplitude interfering with each other. You can't guarantee, in a real
antenna, that the two waves do have the same phase and magnitude.

:-) Hecht was talking about two coherent EM waves traveling in
opposite directions. We are talking about two coherent EM waves
traveling in opposite directions. There is a small traveling
wave component but it doesn't affect the standing wave. It is
what is left over from the standing wave.

This discussion has not been about coils. We need to discuss
an unterminated lossless transmission line and then move on
to 1/2 wavelength thin-wire standing wave antennas.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:

Tom Donaly wrote:

Hecht was talking about two opposing waves of the same phase and
amplitude interfering with each other. You can't guarantee, in a real
antenna, that the two waves do have the same phase and magnitude.


:-) Hecht was talking about two coherent EM waves traveling in
opposite directions. We are talking about two coherent EM waves
traveling in opposite directions. There is a small traveling
wave component but it doesn't affect the standing wave. It is
what is left over from the standing wave.

This discussion has not been about coils. We need to discuss
an unterminated lossless transmission line and then move on
to 1/2 wavelength thin-wire standing wave antennas.

Has it ever occurred to you, Cecil, that a half wave dipole with
equal current and voltage waves traveling in opposite directions
wouldn't accept power?
73,
Tom Donaly, KA6RUH

Tom Donaly wrote:
Has it ever occurred to you, Cecil, that a half wave dipole with
equal current and voltage waves traveling in opposite directions
wouldn't accept power?

It is an approximation, Tom, like a lossless line. For real world
dipoles, the voltage and current decay by about 10% between the
forward wave and the arrival of the reflected wave. Kraus and
Terman both use that approximation in their examples.

We aren't saying anything about the traveling wave part of the
waves. The discussion is about the standing wave portion of
the wave which, by definition, requires equal magnitudes.
--
73, Cecil http://www.qsl.net/w5dxp