[TowerTalk] Open-wire transmission line

[Rob Atkinson]

> In private correspondence, K1XX told me he was trying to "de-tune" a
> tower by dropping down a wire from the top and then connecting it
> to ground through an adjustable reactance.

Then this is a question about how to detune a tower.  He needs a
detuning kit.  I faintly recall that there was an article in QST a few
years ago about how to detune a tower.  BTW if he had asked how to
detune a tower a lot of time would have been saved.    Thank you for
making an inquiry.

>Which brings up an interesting question..
>What would the best impedance be for open wire line, assuming you have some
>sort of tuner at the feeding end,

It's not clear to me where the matching network is.  Is it at the
antenna feed point?  Or is the "feeding end" the end of the feedline
at the transmitter?  If the former, then the line is a flat line
assuming the line's impedance is the same as the impedance looking
into the matching network at the antenna.  Then for your particular
circumstances (power level, and line length) you have to work out a
balance between conductor surface area and spacing for the lowest
resistance while still achieving a useable impedance.  For ham power
and typical run lengths it's not as critical as it may seem, i.e. you
don't have to run rigid copper tubing.   :  )

Rob
K5UJ