Dear Colleagues,
I'm in the final stages of arranging antennas on top of this tower (project)
that you've been reading about since last May. I have run against a dilemma
that I'm not sure is real or imaginary.
Situation:
I have a 72' crankup tower with side-arm "cable loop guides" on each of the
tops of the 4 tower sections. At the top is a 20 foot mast supporting several
antennas. The lowest antenna is a HyGain TH-11DX to be mounted about 1 foot
above the thrust bearing. Above are 4 antennas, including 432 and 1296MHz yagis
at the very top.
My plan is to feed LMR-400 cable directly to all antennas 2M and below and
use LDF4-50A hardline to the top of the tower, joining it to a more flexible
LMR-400 jumper feeding the 432 and 1296 antennas, some 16 - 20 feet above. This
makes a total of 5 feeds of LMR-400. This combination was selected keep the
losses to a minimum. The difficulty of working with hardline & LMR-400 with a
crankup tower has been carefully considered. The conclusion is that lowering
the tower is a two man project.
Problems, questions, dilemma:
1. Is LMR-400 flexible enough to be used with a rotator? My rotator has a 450
degree travel.
2. How do you physically arrange the LMR-400 to allow enough slack for the 450
degree rotation, once out of the top loop? Remember, the HyGain TH-11DX HF beam
antenna is just about 1 foot above this upper loop.
3. How do you terminate/support the LDF4-50A to make the transition to LMR-400
cable?
4. Anyone have photos that might help with this or perhaps a webpage URL
showing details?
All thoughts and suggestions are all welcomed.
73,
Mike DiGirolamo, W4XN
W4XN@arrl.net
Charlottesville, VA
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