A couple of comments on this topic:
1.The raising fixture is used in two modes:
A. Raise tower from horizontal to a modest angle
(perhaps 10 or 20 degrees), without antennas
installed.
B. Then, install antennas and raise the rest of
the way.
The severe mechanical disadvantage when horizontal
does not occur at the same time as the full weight
is installed, because you can't attach the antennas
with the tower laying flat on the ground.
2. Regarding the winch, specifically the Fulton 2500:
If you exceed the 2500 lb rating (one layer of cable),
it gets very difficult to turn the crank by hand.
This tends to limit the amount of load you can put on the
winch. Going down the brake will start to squeel.
Thus winch loading tends to be a self limiting process.
On my HDX5106, I have to use two hands on the winch as
it is, even with no load atop the tower. I think I am
of at least average strength. On the HDX5106, 4 pulleys are
used to give a 4:1 mechanical advantage to the winch. A
rough calculation says the winch is operating near its ratings.
The raising fixture appears to be at no risk of buckling, as
far as I can tell (if I sit on the end of the tower, it is
not springy).
Rick N6RK
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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