I agree with Herb on this one:
Since you have a ground system to reference, the best and most stable balloon
supported vertical IMHO would be the 1/4 wave, or even better yet a 3/8 wave
(185') series tuned to resonance with a capacitor. A 1/2 or 5/8 may not be
exactly vertical all the time (serious pattern distortions), although having a
lower TOA (if they are perfectly vertical) are more difficult to feed. There
is a slight gain on the 1/2 and 5/8 wave but it may not be worth the effort.
Obviously the lift weight of a 1/2 wave is twice as much as a 1/4 wave. But
remember that the winds aloft can be considerably higher than on the ground.
Some balloon radio users, especially those with access to advertising blimps,
use fishing line to guy agains the wind effects.
Using a 3/8 wvl vertical wire, or even a 5/16th wvl (170') may produce a little
more fwd gain over the standard qtr wvl vertical. Like the 3/8 wvl, some
capacitance will have to be added for matching at the feedpoint of a 170'
length.
Don't forget to add plenty of radials, no matter which length you choose. With
radials, up to a point of a quantity of 60 or so, more radials is always
better, no matter what length they may be (assuming something more than 20' or
so). That is, unless you are in the salt flats, as K6SE has tried.
GL CU in the contest
73 George W8UVZ
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