Hi Jamie,
No, you didn't hit a nerve. Its just that use of braid as RF
grounding conductors is a common mistake frequently made by
hams and some professionals. Prior to the 1980s,
manufacturers of grounding kits intended for use on towers
often used braid instead of stranded grounding conductors. To
the best of my knowledge, professional tower installers no
longer use braid for grounding conductors.
If you really want to use braid, you might try enclosing it in
heat shrink tubing. That might apply enough pressure to the
braid crossovers so that they form low resistance joints. I'm
certain that merely stretching the braid will have no useful long
term effect.
73!
Frank
W3LPL
---- Original message ----
>Date: Tue, 22 Nov 2005 19:32:45 -0600
>From: "James C. Hall, MD" <nwtcc@earthlink.net>
>Subject: Re: [TowerTalk] station grounding question
>To: donovanf@starpower.net, towertalk@contesting.com
>
>Hi Frank:
>
>Ouch ! Seems I hit a nerve there. Now, I have used insulated
copper wire on
>several occasions and things like copper water piping as a
common bus on
>which you could connect copper flashing. But now you have
me confused on one
>point - how can the pressure of insulation (or lack of it)
decrease (or
>increase) RF impedance ? If it is a simple 'lack of appropriate
contact'
>without the pressure, it would seem to me that linear
stretching would
>provide adequate contact - at least intuitively.
>
>Just trying to learn something here. Grounding sometimes
gets into the Karma
>of Ham Radio ! HI
>
>73, Jamie
>WB4YDL
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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