You might want to consider the wind loading of the pipe vs cables ?
I seem to recall seeing specs for towers that state the number of feed lines
that can be attached to the tower legs. The wind load of a piece of pipe
might be significantly more than a bundle of cables that can be easily pulled
thru a given size pipe ?
----- Original Message ----
From: David Gilbert <xdavid@cis-broadband.com>
To: Cal Zethmayr <w4gmh@cox.net>
Cc: towertalk@contesting.com
Sent: Monday, April 6, 2009 10:09:08 AM
Subject: Re: [TowerTalk] Co-ax and Rotor Control cables inside PVC?
I'm not sure that the LMR400 would need it, but I've done the exact same
thing for other cables (rotator control, etc). I wouldn't use thin wall
PVC, though ... it generally has horrible UV performance and in the
Arizona sun it becomes brittle and breaks in less than one year. At the
very least I would recommend that you use the thicker Schedule 40 stuff
.. it will discolor but otherwise holds up fairly well. The best choice
would be to use gray electrical PVC conduit and it isn't much more
expensive (Home Depot electrical department). The bell-shaped ends also
make for easier coupling.
73,
Dave AB7E
Cal Zethmayr wrote:
> I'm working on plans for my 110' tower to be installed early this summer.
>
> Considering installing some thin wall PVC pipe inside one corner of the tower
> from near the bottom to the area at the top where the rotor, and an Ameritron
> coax switch box will be mounted. Then put one run of LMR400 in it, the
> cables for the rotor and switch box control.
>
> Purpose: long term protection from any UV, weather etc.
>
> Top of tower will have a HF beam, 6 meter beam, and 2 meter quagi.
>
> Anyone else ever tried this? any ideas or reasons (other than the cost) not
> to try this?
>
> Cal Zethmayr
> W4GMH@cox.net
>
> _______________________________________________
>
>
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>
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