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Old November 15th 07, 12:37 PM posted to rec.radio.amateur.antenna
Mike Kaliski Mike Kaliski is offline
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First recorded activity by RadioBanter: May 2007
Posts: 182
Default RSGB RadCom December 2007 Issue


"Cecil Moore" wrote in message
...
Mike Kaliski wrote:
and that the characteristic impedence will vary along an antennas length.


Well, that's obviously false. The characteristic
impedance of a horizontal wire above ground is
constant at 138*log(4D/d)

The characteristic impedance is not to be confused
with the voltage to current ratio existing on a
standing-wave antenna any more than the characteristic
impedance of a transmission line is to be confused
with the voltage to current radio existing along
its length when the SWR is not 1:1.
--
73, Cecil http://www.w5dxp.com


Cecil

Are you sure you are not confusing the characteristic impedance of a dipole
antenna with the characteristic impedence of an open feed line? One is
constant, the other appears to vary along its length. A dipole antenna has
low impedence at a centre feed point and high impedence at it's ends.

Reminds me of the tales of old ladies who used to tie knots in electric flex
to stop the electricity leaking out! I actually met one in real life many
years ago.

Mike G0ULI