Sitting around discussing the problem of putting up big antennas in a new
suburban residential tract with my wife, we came up with some interesting
1) Most hams (especially those with full time jobs) spend a small fraction
of the hours in a day, month, or year actually operating. When you're not
operating, you don't need the antenna.
2) The concerns about big antennas are mostly aesthetic ones, even if they
are dressed up and portrayed as safety concerns.
3) The hours when you're likely to operate tend to be at night, when a big
antenna is less visible.
what if you had a really big antenna that could almost instantly
disappear? Say you had a 150 ft tower with a array of SteppIRs that could
deploy in 5 minutes, and could stow in 5 minutes. When stowed, it might
look like an innocuous garden shed. (or, to be more reasonable, a 40-60 ft
tower with a single 3 element SteppIR)
Think of something along the lines of those nifty tower trailers, the link
which was posted last week. You'd also need a nonstandard antenna design
that can also fold up and deploy. I think it would be possible to engineer
such a thing to meet all legitimate safety concerns: For instance, it might
need explicit design features to insure that if it fails, it falls in your
Sure, it would be (a lot) more expensive than a big stick of Rohn 45 or a
crankup, but, hey, if you're living in a controlled neighborhood and
working full time, you might well be able to afford it. And, it might be
cheaper than buying land somewhere and setting up a remote controlled
station with fixed antennas.
You might even be able to put the whole thing in a hole in the ground. My
wife was less than impressed by the prospect of a 10x10 ft shed in the back
yard, no matter how tastefully decorated.
This is not as impractical as it might seem. As a starting point, imagine
drilling a 3 ft diameter hole and sinking a standard crankup tower into it,
with just the mast sticking out. You've automatically given yourself a
great base to resist the bending moments, with a big pier, that just
happens to be hollow. Another design alternative is a pneumatic tubular
mast. I've seen some very impressive pneumatically operated masts that
shoot up 40-50 ft in just a few seconds.
Folding a SteppIR isn't as impractical as it might seem. Hinge the boom
and the driven elements UP, and the end elements DOWN (from the ends of the
boom), and the whole thing would turn into a bundle of 8 tubes, and could
probably fit in a 2 ft diameter cylinder. The conductive part of the
elements can retract all the way into the motor units, so you don't have to
worry about folding the element, just the tube, and there are off-the-shelf
hinges for this kind of thing.
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