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Old October 24th 08, 07:01 PM posted to rec.radio.amateur.antenna
Mark Mark is offline
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First recorded activity by RadioBanter: Nov 2006
Posts: 27
Default Antenna design question

On Oct 24, 1:29*pm, wrote:
On Oct 24, 6:48 am, Michael Coslo wrote:

Trying to make a "readers Digest" version here....


If I'm following so far:


The lowered frequency of resonance is due to changes in the velocity factor.



so as the wire gets thicker the C per unit length goes up at some rate
and the L per unit length goes down at some other rate, fine so that
reduces the characteistic Z by some rate....but none of that changes
the wave velocity as was pointed out above in the coax example.

I think the shortening effect may all be due to the extra C of the end
surface, i.e it iss end effect. For a thick wire, the end is a circle
that has C and this is all extra C that is not present for the thin
wire. Is this extra C alone enough to create the shortening effect?

Mark