Hi all,
Looks like I'm going to have a 50 foot crank-up
tubular tower. 23 feet tall when nested.
Self-supporting in 4 yards of concrete, probably.
I'll be putting a tribander on it. The rotor will
mount at the top of the tower - this is not a rotating
tower.
How do I get the tribander up there? The yard in
which the tower is planted is far too small for the
antenna to be fully assembled at ground level.
Until I get up to 12 feet off the ground, there is
house, shed, fence, or tree within 10 feet in every
direction, except for a 30 degree arc where the
distance is about 20 feet. Because of zero lot lines
and houses within a few feet on each side, there is no
way to get a boom truck back there.
Assuming it's a triband Yagi, I think the approach is
to mount the boom at the 12 foot height level. This
isn't trivial; the tower is 6" diameter at that
height. So I think it will involve a homemade
temporary bracket of some sort, possibly made of wood
and employing hose clamps somehow. Haven't sorted out
that detail yet, but I think it's possible.
Then, using a large stepladder, install the elements
to the boom, while the boom is at the 12 foot height.
Then, somehow shinny the beam up to the top of the
tower, in the process getting it past the rotor.
So, it sounds like I'm going to have to climb this
tower while it's nested.
Has anybody done this before? I can imagine adding
various brackets, again probably wood bits clamped to
the tower, for foot rests, to enable climbing it. I'd
have to consider very carefully how to attach the
climbing belt - I won't sacrifice safety. If the
method of climbing is slow, that's OK, as I don't plan
to do it much.
Once the beam's shinnied up to just under the rotor,
have to figure some cable/chain, etc configuration so
that if I lose hold of it while moving it to a
position above the rotor, it can't fall.
The whole thing seems more possible because the
"height" work is only at 23 feet, not 50, but it's
clearly not without risk.
A possible alternative is to attach a pulley to the
top and haul the beam up that way. I still have to
get myself up there to do the attaching, which will
require again either climing the thing or finding a
ladder tall enough, which is not a trivial task in
itself.
Thoughts? Alternatives? BTDT?
Thanks for tolerating me as I "do" my very first tower
install...
73,
Dave W8NF
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