In a message dated 96-12-20 15:02:19 EST, you write:
>I know that a tower mounted ON, not in/through a
>concrete base needs a grounding cable. But in
>the case where the tower, Rohn HDBX-48 in my
>case, will be mounted onto metal stubs (BXB-8)
>that go through the concrete and are touching
>the ground underneath, is it still necessary
>for an additional grounding cable?
>
>I've got a feeling that there are some codes
>governing this but I just don't know where to
>turn to get them. The Rohn manual for the
>HDBX-48 doesn't specify anything in the way of
>grounding.
Yes, you tower should be grounded. There is a ground called an Ufer
ground that uses the concrete and rebar in your tower base as a ground but
everything needs to be bonded so your base probably isn't a 'proper' Ufer
ground.
The NEC (National Electrical Code) specifies what you should do and even
covers the size of wire to be used for antennas.
Whole books have been written on this topic. For an informative reprint
that I have written on grounding for hams, send an SASE with 2 stamps to
TOWER TECH, Box 572, Woodinville, WA, 98072. The reprint covers ground rods,
bonding, single point ground system and much more.
73, Steve K7LXC
TOWER TECH -- professional tower supplies and services for amateurs
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