[TowerTalk] Question of Efficiency

[ABowenN4OO]

ARRL Compendium 7 had an article that might be useful for your 
application. The article, Untangling the Folded Unipole, by N7OP, 
shows how to configure a folded unipole for use on several bands. 
Folding the antenna raises the feed impedance, but does nothing for 
the efficiency. Shorting the fold wires to the tower, as discussed in 
the article, would be a convenient way to cover 3 bands.

The downside is that a matching system, would be required for each 
band. The folded element exhibits inductive reactance, so it is 
possible that only a series capacitor would be needed. Another 
suggestion would be to use an auto tuner unless you plan to use power 
of a KW or more. I am not aware of any reasonably priced tuners that 
handle the legal limit.

INK N4OO