Bill --
The only reason I can think of to have the coax
inside the tower is for lightning reasons. If this is
your rationale, then I would bring it outside the tower
at the rotor shelf, tape it to the outside, and start the
rotation loop near the top of the tower. The lightning
reason to put it inside is that the tower forms a
faraday shield. Nevertheless, you will have lightning
skin effects on the top part, and where the coax exits
the tower. That's where you might get arc-over on
a strong strike. I don't do it, but it's best to
ground the cables at the bottom of the tower, and also
put fairly large coax baluns there as well. (See W8JI's
post recently on this.)
Re the loop, I sometimes take an old rubber hose &
slit it lengthwise to slip over the coax in the loop. You'd
need to tape it. If you remember to put the hose on
before you put the connectors on, you don't need to
slit it! The hose takes the brunt of the abrasion - what
little there is.
73,
Tom Wagner - N1MM
Check out the N1MM Free Contest Logger at
http://pages.cthome.net/n1mm/
http://groups.yahoo.com/group/N1MMLogger
----- Original Message -----
From: Bill Coleman <aa4lr@arrl.net>
To: <towertalk@contesting.com>
Sent: Friday, July 20, 2001 09:20
Subject: [TowerTalk] Question - Routing of Coax around Rotator Shelf
>
>
> I'm steadily working to put up my 44' Rohn 25 bracketed tower. While
> planning ahead, I ran across something I'm not entirely sure how to
> handle.
>
> I know that you're supposed to route all cables INSIDE the tower. This
> works for me right up to the 40' level, were the standard Rohn AS25
> rotator shelf completely blocks the tower interior. In my case, I have an
> AG3 top, so there's still a couple of feet of tower to route the cable
> within.
>
> How do others do this?
>
> * Jump around the shelf, bringing the coax back in, and up the tower leg
> before the rotation turn loop where the taper stops.
>
> * Go outside shelf, leaving the coax outside the tower before the
> rotation turn loop.
>
> * Starting the rotation turn loop at the shelf.
>
>
>
> Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
> Quote: "Not within a thousand years will man ever fly!"
> -- Wilbur Wright, 1901
>
>
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> -----
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>
List Sponsor: Are you thinking about installing a tower this summer? Call us
for information on our fabulous Trylon Titan self-supporting towers - up to
96-feet for less than $2000! at 888-833-3104 <A
HREF="http://www.ChampionRadio.com";>
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-----
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