[TowerTalk] Change in Frequency with Height above Ground

[TexasRF at aol.com]

John, you could consider the two balun wires to be a balanced transmission  
line and model the effect of that. For example, if the wire spacing was 4 
inches  and the diameter was .1in the impedance would be about 525 ohms. If 
the length  was 6 inches, at 14 Mhz it would be 2.6 degrees long.
 
Connecting a 50R termination to that and using transmission line software  
would result in a 50.1 +j24 value. The antenna feed point would need to 
present  a 50.1 -j24 value to match.
 
Gerald K5GW
 
 
 
In a message dated 5/27/2016 8:10:24 P.M. Central Daylight Time,  
john at kk9a.com writes:

Yes the  balun leads are part of the antenna. I have not ever modeled them
and I  typically have to shorten the DE a little. Is there an easy way to
model  these, it is such a short segment and the leads are somewhat  
parallel.

John KK9A

To:     <towertalk at contesting.com>
Subject:    [TowerTalk] Change  in Frequency with Height above Ground
From:    "Jim Thomson"  <jim.thom at telus.net>
Date:    Fri, 27 May 2016 14:25:26  -0700

The wire leads from balun  to feedpoint will also lower the  resonance
point.... but that is moot, since most folks know the leads are a  part of
the  ant.

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