Good point about rotation, guess you could get two directions without
turning. But, not many do that long path vs. short path all the time?? You
still have to have a rotor to do all possible directions! I was just
studying tower loading paper in QST and the major forces on the tower are
the antenna wind load, and the wind itself against the tower faces, NOT the
weight of a rotor that is usually within the tower. I would say that a
linear decoupled tri bander, or the multi monobander Force 12 models would
also be cost competitive.
Feed line loss would be same for any type of beam unless you are referring
to retuning across the band. Most beams, that would not be a major loss to
have them tuned at mid band, and used at both ends.
A major ham misconception is that the efficiency of an antenna is affected
by the resonance or not. Non resonant doublet antennas radiate just as well
as the carefully cut half wave dipole. They just need a transmatch because
they present non zero reactance to the feeder. Resonance is just the state
of having no inductive or capacitive reactance. See L. B. Cebik's book,
"Antennas from the Ground Up". Or many of the monthly postings in World
Radio magazine by Kurt N. Sterba, their antenna Guru. I always preferred
resonant antennas, but use of 5/8 wave at 80M doublets on higher bands and
greater than one wave horizontal loops for 160M at higher bands has showed
me that having more radiator counts the most. More capture area vs.
frequency (wavelength).
I am sure it is a very nice antenna for certain types of operations, but
having to replace fans in computers every two years makes me distrust small
motors. These may well be the finest ball bearing precision types, but of
course you pay for what you get.
73,
Stuart K5KVH
No, you miss my point. IF the elements are same size as other beams, then
to be inside a fiberglass radome, there outer enclosure diameter must be
greater wind load than a conventional tubing element.
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