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Re: [TowerTalk] Lightnig Arrestors at tower base or house entrance?

To: K7LXC@aol.com
Subject: Re: [TowerTalk] Lightnig Arrestors at tower base or house entrance?
From: "Roger (K8RI)" <K8RI-on-TowerTalk@tm.net>
Date: Mon, 25 Feb 2008 22:39:46 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
K7LXC@aol.com wrote:
>  
> In a message dated 2/25/2008 5:38:57 P.M. Pacific Standard Time,  
> towertalk-request@contesting.com writes:
>
>   
>>  Could someone please explain how you can ground a coax  shield, on a 
>>     
> continuous run down a tower, without letting moisture and  humidity get 
> into it? Thanks!
>
>
>          Commercial ground  kits include a bunch of butyl rubber vapor wrap 
> and 2" wide electrical tape.  It's pretty easy to do with the right 
> materials. 
>  
>         You cut the jacket away,  attach the ground wire and weatherproof. 
> And no kinks in the ground wire - just  a sweeping run to the attachment 
> point.
>  
>         Commercial ground kits use  compression for the shield connection. 
> Trying to ground a small cable like 1/2"  coax isn't as easy as the bigger 
> cables. 
>   
I'd call that an understatement<:-))
However with a bit of ingenuity and using the appropriate size of copper 
pipe or tubing it's not all that difficult to make some good looking 
ones that work well.

Take a length of  the copper pipe (say 6" long) or tube with an ID about 
the same or *slightly* larger than the diameter of the coax with the 
jacket removed.  Split the copper tube or pipe lengthwise (IOW saw it 
into two mating pieces).  Solder/Braze the  ground wire *lengthwise* 
onto the outside of one half.   Clamp it to the braid by wrapping the 
sections with the rubber vapor wrap and tape which also water/moisture 
proofs the connection.

This approach is actually easier to do on the small cables we typically 
use than some of the commercial kits.

The most difficult part with the really small cables such as LMR 240 is 
removing the jacket without ruining the braid. RG-8X cables with both 
single and double shield are easier than the 240.  Carefully *score* the 
jacket with the tip of a box cutter and apply pressure to cause the 
jacket to split. Don't let the blade penetrate through the jacket to the 
braid which is very fragile.

I don't currently have photos of any I can show that would give any 
meaningful information, but if my memory holds long enough I'll try to 
make up some (along with photos) for the feed lines to the sloping  
dipoles I'm installing and the ones  for the runs to the arrays "up top"

73

Roger (K8RI)
>  
> Cheers,
> Steve     K7LXC
> TOWER TECH
>
>
>
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