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Old September 10th 06, 09:27 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Mobile antenna shootout results?

On Sun, 10 Sep 2006 08:02:14 GMT, "Alan" wrote:

I guessed they might be but does anybody use a smaller antenna as a
compromise?


Hi Alan,

Sure. So's the signal (a compromise). When you get into fractional
wavelength sizes (and we're talking on the order of less than 5% of
wavelength), you quickly get into fractional performance. It has to
do with the comparison of the radiation resistance which at 5% is 2
Ohms. This is 25:1 mismatch, and the matching components are going to
have to present less than 2 Ohms in themselves (not forgetting all the
connections that support the circulating currents) just to limit your
loss to 3dB.

If it were easy, few shootout contestants would be running 10dB below
the winners.

Still and all, even if your 100W signal ends up radiating 10W, lots of
folks have worked the world with less.

73's
Richard Clark, KB7QHC