In a message dated 12/15/2006 11:52:12 A.M. Pacific Standard Time,
towertalk-request@contesting.com writes:
> I will be helping a friend erect a 100' 45G (plans changed from 190' to
100' due to county permitting issues; the tower is to get 900mhz internet, not
amateur application and thus subject (in our county) to more regs).
> The guys are to be at 31, 61 and 91' according to the drawings.
> Questions: First, is there a "strong" reason not to guy at the 100'
level, when all that is going up is the access point, it's directional antenna
to
the backhaul, and a small omni-directional antenna?
The reason that the Rohn drawings typically show the top guys below the
top of the tower is that the drawings only consider a commercial antenna
load; that is, there'll be omni antennas or dishes mounted at the top and the
guys would be in the way of the antennas and mounts - it's just a practical
consideration.
Yes, put your guys for an amateur installation at the top of the tower.
Either there or near the rotator plate since that's where the wind induced
torque shows up. That way the torque goes from the antenna and mast and
rotator
more directly to the guy wires rather than torquing a tower section. Either
method is FB.
> Second...what about temporary guys when putting it up. If we don't use
them, he'll be up on 3 sections of unguyed tower, which just doesn't seem
right ;). What material should we use for them?
If the bottom section is in concrete you don't need temporary guys.
Would you put temporary guys up the whole way? You don't have to. The naked
sections are plenty strong - you'd need something like having them hooked to
your
car and then driving away before you'd pull them down. Climbing them is
basically a psychological problem and potential pucker inducer. If you don't
feel
confident on them, get someone who is.
OTOH if you're using a pier pin base, then yes, you'll have to
temporarily guy them up to the first set of guys. Large rope or wire cables
work fine.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for hams
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