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Subject: [TowerTalk] FORMING COAX ROTATION LOOPS - Summary
From: (Lowell, Mark)
Date: Thu, 25 Jun 98 09:40:48 -0400
Thank you again, to all those that responded directly, with very helpful
comments on forming said loops. Copying the reflector in your replies
would put out the info for all in one stroke.

 I have paraphrased the comments for a summary post here. There was a post
recently about how a tower is raised and that got me thinking. I think we
must acknowledge that many readers are looking for more basic information.
 That's certainly what got me reading. I hope the more experienced of you
will bear with us, and refine our understanding with your experience.

Here goes, hope this helps someone:


  You must allow the coax some extra slack to flex as your rotator moves
the antennas back and forth. The first step is to set the rotator to the
middle of its stroke, halfway between stops. If you rig your loop this
way, it will only have to withstand half of the rotor's full stroke each
 Secure the cables to the mast below the bottom antenna. This can be done
with tape, followed by gently snugged cable ties (for extra strain
relief, since this is a stress point), covered with more tape to protect
from UV. Wrap the coax/cables around the mast 2 times, forming a loose , 8
inch diameter spiral below the tape point. This can also be performed by
loosening the mast in the rotor, and spinning the mast and antennas
around. Don't pull these turns tight around the mast. They should have a
diameter no smaller than recommended for the size coax you are using.
Certainly not smaller that 8 inches in diameter for the RG-8/RG-213 sizes.
The spiral of extra turns distributes the twisting along a longer section
of cable, resulting in far less fatigue that the usual loop that just
comes out sideways and back to the tower.
  If you have a tapered top tower, at this point, you can secure the
coax/cables to the tower as above, starting from the top and going down.
However, if you have a flat top tower, the top plate will have some rough
edges that will tend to chafe the cables' jacketing. Bolt or clamp a short
pipe to one of the tower legs that rises a few inches above the plate's
edges. Begin attaching the cables to this riser and work your way down the
tower. The riser will keep your cable spiral from catching on the top


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