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Old September 19th 06, 02:06 AM posted to rec.radio.shortwave
Lisa Simpson Lisa Simpson is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 80
Default Impedance of a wire over the earth

VERY useful and refreshingly on-topic post! Thank you!


wrote in message
oups.com...
Given the on going OT flame feast I decided to enliven everyone's day
by posting something actually on topic.

Many, maybe most, or us have a random wire for an antenna.

Many may have wondered what the impedance of that wire might be.

http://www.microwaves101.com/encyclopedia/calwground.cfm

Enter 1 for the Permitivity. While insulation will have a very minor
effect, the air surrounding the antenna will swamp the insulations
contribution.

Wire size can be found at
http://www.tfcbooks.com/referenc/wiresize.htm.

Because most real world wires sag, I pick the highest point and lowest
point
and average them.

Tests with a receiver and a RF noise bridge shows measured values very
close
to the calculated values.

Terry