TowerTalkans --
I'm planning my first tower, a US Tower TX-455. My building permit was
approved today, so Im about ready to order the beast. Some questions if
anyone would like to share the benefit of their experience with me.
I would like to put a Force12 C3E (5.8sf windload), a D3W 30/17/12 rotable
dipole (.9sf), and a small 3 element 50mhz beam (1.8sf) - a total of 8.5sf.
This is below the 70mph rating for the tower. I havent added in a value for
the mast.
a) Im allowed a height of 65', or 10' of mast above the tower. Is this
enough to space these three antennas, or will there be serious interaction
problems?
b) What length mast do I want to have 10' above the tower? Im asking what
the distance between the rotor shelf and the top of the tower is
essentially. Is the rotor shelf in a fixed location or can it be
raised/lowered?
c) Do I want to use one of USTower's "reinforced" masts? They have steel
inserts in the bottom half.
d) Do I want to use a thrust bearing? I assume Yes.
e) It would seem logical to put the largest antenna, the C3E, at the bottom
of the mast, with the 6 meter antenna in the middle, and the 30/17/12 dipole
at the top. Could I get away with reversing the order and having the C3E at
the top? Its the one Id like the highest. Im guessing this is a bad idea.
f) US Tower sells a mast raising fixture to help pull the mast up. Is this
essential? I assume it depends on what is on the mast and I dont think a
D3W and 6m beam will be very heavy.
Thanks for any responses. And yes, I can also ask US Tower some of these
questions, but Id like to hear from others as well.
Dana
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