[TowerTalk] Re: TopBand: 75 meter vert. fed with open wire

[w8ji.tom]

Hi Lane,

> I just finished putting up a full size 75 meter 1/4 wave vertical. Roof
> mounted (actually next to the roof but close enough). Of course all
radials
> are elevated. Six of them are 46 feet long. Two are 66 feet long. Open
wire
> feed is 450 ohms.

The feedline will be part of the antenna and radiate in this setup Lane.
Feeding an unbalanced antenna with a balanced line is a poor method. You
can only cure the problem with a choke balun at the antenna terminals (and
also one at the other end if you aren't using a balanced tuner).
 
> I am using it on all bands 80-10 meters. Really seems to hear and xmit
well
> (subjection only). Was wondering what the take off angle is on the other
non
> 75 meter bands?? Does it get lower as the freq increases or does it get
> really complex??

I'm sure it gets pretty complex, especially since the feedline is certainly
contributing to radiation. Wave angle should increase with increasing
frequency.
 
Like with all antennas, the only thing important is how well you like it
and how you feel it works. That's always much more important than what is
really going on.

73 Tom

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