[TowerTalk] Lightning protection grounding

[Bob Wanderer]

Read the first paragraph below again carefully.
This wire would not carry much of the current.
Also, if you place it too close to the coax, you
can have a flashover. That is why the shield of
the coax needs to be bonded to the tower at the
top, bottom and intervals of 75~150 ft for towers
greater than 150 ft (obviously more a concern for
commercial sites).

The best method to use would depend on how often
you cranked up and down your tower. 

There have been several postings regarding the
necessity of jumpering. I believe it necessary, but
the posters who disagreed are entitled to their opinions.

73,
Bob AA0CY

----------
From:  Dave Jordan[SMTP:wa3gin@erols.com]
Sent:  Friday, April 16, 1999 5:48 AM
To:  Bob Wanderer
Cc:  'David Leikis'; towertalk
Subject:  Re: [TowerTalk] Lightning protection grounding

Why can't a person simply run a ground wire from the top section/mast of the
crank-up down along with the coax and terminate the wire to the ground
system at the base?
===================

Bob Wanderer wrote:

> The conductor running down the inside of the tower
> to ground is unnecessary. It carries maybe 10~15%
> of the total current.
>
> However, there is higher resistance between
> two sections of a crankup which could benefit from
> straping the two sectiuons with copper strap. The problem
> is then how do you crank the tower down? If you make the
> straps long enough to allow crank down, they will flap in the
> wind. Making them short jumpers obviates the convenience
> of the crankup. I guess you have to decide which situation
> is the more tolerable.
>
> 73,
> Bob AA0CY
>
> ----------
> From:  David Leikis[SMTP:dlleikis@deseretonline.com]
> Sent:  Sunday, April 11, 1999 9:40 PM
> To:  towertalk
> Subject:  [TowerTalk] Lightning protection grounding
>
> Hello,
>
> I have seen many recent postings concerning grounding methods and saw
> one that stated to run a ground conductor up the mast to the final
> section (and the others as well) to prevent any high resistance points
> along the way through the joints.
>
> My question is this:  I am erecting a self-supporting crankup and am
> concerned about the sliding joints of the installation.  It seems as
> though these would definitely be high resistance and would need this
> more than any other.  What is a recommended method from those that may

> have done this before?  We can have some pretty severe storms here and I
> am positive (or negative)  that lightning charge dissipation should be
> 'high' on my list.
>
> Dave KG7EW
>
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