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[TowerTalk] 1/4 wave 160

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Subject: [TowerTalk] 1/4 wave 160
From: (Pete Smith)
Date: Tue, 05 Feb 2002 22:15:09 -0500
At 07:17 PM 2/5/02 -0600, wrote:
>On Tue, 5 Feb 2002 "Sain'T Tom" <> writes:
>> Anybody got any REAL WORLD and WORKING height dimensions 
>> of a 160  meter quarter wave vertical made of Rohn 25?
>> Thanks
>> Tom K4RV
>The ARRL Antenna Books (and Handbooks?) have a graph showing
>% of freespace length vs. L/D ratio of the 1/2 WL wire (or element).
>I believe someone indicated that Rohn 25 could be modeled 
>as a cylinder of 8 or 9 inches diameter, 
>OR, you could model it as 3 cylinders of 1-1/4 inch diameter
>in a triangle 11-1/4 inches center to center with the ends 
>connected.  I assume you are not planning for any other 
>antennas on the tower / vertical.
>If you are going to shunt feed it, anything close will work.

Until you try to model the shunt feed attached to a cylindrical model of
the tower.  Then the unequal diameters connected at an acute angle give
wildly improbable results.  Thanks to K6SE for straightening me out on this

AFAIK, the only way to get reasonable results is to make the conductors in
the tower model the same size as the conductors in the shunt feed.

73, Pete N4ZR

Sometimes a tower is
just a tower

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