[Top] [All Lists]

Re: [TowerTalk] Coax Arms for Tri-Ex Crank-Up Towers

To: Larry Essary <>
Subject: Re: [TowerTalk] Coax Arms for Tri-Ex Crank-Up Towers
From: jimlux <>
Date: Thu, 29 Oct 2009 04:12:27 -0700
List-post: <">>
Larry Essary wrote:
> Has anyone found an improved method for running coax down crank-up towers ?
> I have seen the fixed arms where the coax "accordions" as the tower comes 
> down.
> I have been told that even with the tower fully extended the coax whips 
> around in the wind
> I have seen the "loop" or ring standoffs where the coax "threads the needle" 
> as 
> the tower comes down and the coax piles up on the ground or in a container.
> I would think there is a lot of stress on the cable having a single 
> attachment point
> at the top of the tower. Also some logistic problems with the coax piling up.
> Any improved ideas ?

Are you cost constrained?

You could have a large spring loaded reel at the bottom that feeds/takes 
up the cable.  One would want to choose a coax that is designed for 
repeated movement (yep, that Andrews hardline would be a bad choice). 
Think of the retracting reels for air hoses and cords.  They're 
available in all manner of sizes up to tens of feet in diameter (you see 
them on gantry cranes for instance)

As for the tension on the cable.  They make nice woven grips that hold 
the cable, and then it's a matter of choosing a suitable cable with 
sufficient strength or running a strength member along side the cable 
(like cable TV drops that have the steel messenger cable in the jacket). 
  There are flexible low loss cables made for this kind of application, 
although I'll bet they're not cheap.

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>