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Old January 10th 08, 03:59 AM posted to rec.radio.amateur.antenna
Cecil Moore Cecil Moore is offline
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First recorded activity by RadioBanter: Aug 2006
Posts: 572
Default Standing morphing to travelling waves. was r.r.a.a Laugh Riot!!!

On Jan 9, 7:48 pm, art wrote:
Thus it is the length of the antenna by your statement is what turns
around the current regardless of the frequency applied.


The feedpoint impedance of these standing wave antennas can be closely
approximated by

Zfp = (Vfor+Vref)/(Ifor+Iref)

where all values are phasors. For instance, the reflected voltage will
be out of phase with the forward voltage at the feedpoint for a
resonant 1/2WL dipole while the reflected current will be in phase
with the forward current. The feedpoint impedance of a 1/2WL dipole is
very close to (|Vfor|-|Vref|)/(|Ifor|+|Iref|). See if you can figure
it out for other lengths of dipoles.
--
73, Cecil, w5dxp.com