LMR-400 is a poor choice for outdoor use, Even Times Wire rate its life
at 10 years. It is flexible, but the jacket does not hold up. It's a
rubber like material that is easily abraded. I had 5 28' pigtails that
also served as rotator loops. 4 abraded to the point that the fpil was
visible. One looked good, but the jacket was no longer waterproof. For
flexibility and slippery, I'd go with Davis BuryFlex.
I managed to get 6 years out of the LMR400UF. I have a bunch of LMR600UF
that I purchased before I found out about the short lifetime.
I now use it in conduit to the towers.
73
Roger (K8RI)
On 8/31/2016 Wednesday 8:29 AM, john@kk9a.com wrote:
I concur that using the same cable from the radio to the antenna 270 feet
away is a poor choice. Some cables are flexible and some have lower
losses. I was going to make a similar suggestion when I initially read the
post. I have many very different cables going from the shack to the
antenna.
It sounds like your stacking relays are mounted up the tower. While
slightly more costly to install, I think that they are better at ground
level. It is much easier to check for individual antenna problems and
relay issues while standing on the ground.
John KK9A
To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] Questions
From: "Ed Sawyer" <sawyered@earthlink.net>
Reply-to: sawyered@earthlink.net
Date: Wed, 31 Aug 2016 01:23:52 -0400
I think it's a mistake to run the same cable for 270ft for this application.
I would run the lowest loss you can afford for the main run - LDF4 or LMR600
and then shift to a more flexible cable at the tower - LMR400flex or worst
case RG213.
I run 3 sets of coaxes for my systems. LDF5 from the shack to the switching
at the towers. LDF4 from there to the stack matches and them LMR400flex
from the stack matches to the beams.
Ed N1UR
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73
Roger (K8RI)
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