[Towertalk] Rotor Loops

[Pete Smith]

At 05:27 PM 11/23/02 -0600, you wrote:
>Another method that I can envision is to have the coax come off the mast and
>tower PARALLEL to the horizon and do the loop in the horizontal plane.  Now
>the coax will coil and uncoil versus twisting.
>
>Would this be better for the coaxial cable in the long-term?


Actually I asked about this not long ago.  Here's what I was told.

You'll notice that the television remote trucks have a rotating dish on the 
top of their pneumatic masts, and they coil the semi-rigid UHF coax around 
the mast a number of times on the way up.  As a result, a 360-degree turn 
in the unwinding direction just loosens the coil on the mast somewhat.

I actually use a hybrid of the two methods on my yagis, one of which has 
450-degree rotation.  My rotator loop is about 2 turns of non-rigid coax 
(RG-213) that is wrapped around the mast, with the rotator against the stop 
where it is almost tight on the mast.  Unwinding 450 degrees then loosens 
the turns but does not entirely unwind them.  In retrospect, next time I'd 
use 4-5 turns.  On the other hand it's been up 7 years...

73, Pete N4ZR
Sometimes a tower is just a tower