hi Chris !
when we started to do 136 in the late 90s, i had a 100 ft tower with
umbrella type tophat sitting on 1.5 inch Teflon blocks.
8000 pounds of steel winched with hydraulic tools onto it. loaded with
a series adjustable coil. Worked OK from Italy to Scotland with audible CW.
But after first enthusiastic experiments, the number of workable
stations declined and now i have a 6 el for 15m on it.
I have one of the Versatowers here to suspend another yagi, and it has
the extension piece in it. I doubt whether it is possible to use Teflon
under constant mechanical stress, it will do a cold flow and come loose.
From the electrical point of view, u dont need the large conducting
surface of the steel tower at that impedance. I would rather run a
vertical wire some ten feet away parallel to the tower up to Your
toop-hat loop. of course suspended at the top by a beefy insulator of
sufficient length.
Create Your own ground screen with the feed say ten feet away from the
tower base.
In short, You are feeding at a high impedance point, therefor the thick
tower is of no extra benefit as an RF- conductor.
73 de wolf df2py
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