Next weekend, I plan to climb the 80' Rohn 45G tower at our
club station (W5RRR/Johnson Space Center ARC) and remove
the rotator. The rotator is on a rotor plate inside the tower. A
thrust bearing is on the top tower plate. The bearing support
no vertical load. The mast is about 15-20 ft and carries a 204BA
(lower) and a 15-4CD (upper).
I need to remove the rotator and do some bench work/testing
in the shack for a potentiometer problem it exhibits. I am sure
I cannot repair it, but need to verify that it is not repairable
locally before we send it off.
My questions of the reflector are:
A. What is the best way to secure the mast segment within
the tower so that it (1) doesn't drop down putting the 204BA
boom-mast clamp plate on the thrust bearing; and (2) doesn't
allow the array to tilt?
My plan is to crowbar the mast up off the rotor, block the
204BA boom (it is only inches above the thrust bearing)
to take the mast weight off the rotor, strap and tie the lower
mast segment equidistantly between the tower legs, then
remove the rotor.
B. How do you determine if your rotor is a Ham-M, Ham-II,
-III, -IV? Is there any external difference/indication? The
rotor controller for this tower is the CDE brown and eggshell,
three-button box, which means it may be anything from a -II
on up.
Comments? Suggestions?
Thanks in advance.
73,
Dale Martin, KG5U
kg5u@hal-pc.org
http://www.hal-pc.org/~kg5u
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