In a message dated 97-06-07 07:01:32 EDT, ftbrady@cosmoslink.net (Frank T.
Brady) writes:
> I just had a conversation with the contractor who is doing the site
> preparation (utilities, etc) for the vacant property we're developing for
> our new home/ham site. When I suggested that I would like to have him do
> the digging and concrete for the tower footing, he asked if I wanted any
> 'copper sheathing' in the hole the way he was instructed to do it for
> another tower he installed.
>
A tower base and rebar can be used as part of the ground system. An Ufer
ground is this technique; the rebar is (typically) welded together and
connected to the anchor bolts or base fixture. Since the concrete is
conductive, it can be either a part of a single point ground system or a
primary point of a restricted space ground system.
Copper sheathing, or strap, is commonly used in some ground system
installations where there is high ground resistance such as rocky soil. It
gives you more surface area for the conductor.
> Is this something to consider? I don't know whether it was done to get a
> great RF ground or for lightning protection (or both). If there is a
> worthwhile electrical procedure that can be done in the tower footing, I
> sure want to learn more about it before the installation.
>
I don't know what part of the country you're in or how big of a problem
lightning or grounding is but there are some design considerations if you
want to do a good and effective job. I have a free reprint of a paper I
wrote on Grounding Systems For Hams that covers the topic pretty well (there
are whole books written on the topic). An SASE to TOWER TECH, Box 572,
Woodinville, WA, 98072, will get you a free copy.
73, Steve K7LXC
TOWER TECH -- professional tower supplies for amateurs
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