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Old May 20th 06, 03:36 PM posted to rec.radio.amateur.antenna
Tom Donaly
 
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Default FIGHT! FIGHT! FIGHT!

Cecil Moore wrote:
Tom Donaly wrote:

Cecil Moore wrote:

Seems the easiest measurement of nonlinearity would be the
harmonics (if any) generated by the antenna that do not
appear in the source signal.



Which wouldn't tell you a single thing about the current
distribution along the length of the dipole.



Yes it would. It would be proof that the current distribution
along the length of the dipole is sinusoidal no matter what
your illusionary perceptions are telling you.

For standing wave antennas, if the source is a pure single
frequency sine wave and if no harmonics are generated
by the antenna system:

1. The forward wave is sinusoidal.

2. The reflected wave is sinusoidal and coherent with the
forward wave.

3. Their superposition results in a sinusoidal standing wave
with the same angular velocity.

Any non-linearity would introduce harmonics.


The purpose of most antennas is to radiate electromagnetic waves.
That means there is loss. It also means that the current envelope is
affected. That's one of the reasons we use EZNEC. I suppose, Cecil,
that if you keep repeating the same old tired line, over and over
again, you might find someone who will agree with you. Certainly,
no antenna measurement would.
73,
Tom Donaly, KA6RUH