[TowerTalk] resonant coax braid effect on ants?

K7LXC@aol.com K7LXC@aol.com
Wed, 13 Oct 1999 15:05:56 EDT


In a message dated 99-10-13 14:26:56 EDT, af006@lafn.org writes:

> I recall a discussion with a guy who had a bunch of commercial antennas some
>  time ago.  He brought all the coax cables down to the base of the tower
>  where he attached a grounding bus to the shields.  I thought he was crazy
>  but he said he did it to reduce cross coupling from coax radiation.  I
>  pointed out that the antennas where in close proxin\mity and that they 
would
>  couple too!.  I never did get an answer -- could this be a way to insure
>  non-resonant coax feedlines?
>  
      Don't know about the cross coupling but this is a typical cable 
grounding scenario. Outer shields are typically grounded at the antenna, at 
the bottom of the tower before the cable turns towards the building and then 
at the building entry panel. I'm sure there are other benefits - cross 
coupling may be one of them - but it's primarily for lightning protection.

Cheers,    Steve    K7LXC
Tower Tech

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