[TowerTalk] tower & antenna project questions

[Steve, W3AHL]

Wiring the J-bolts and rebar is generally not considered adequate for lightning protection!  Welding or exothermic bonding is used for the commercial towers I've seen.  

http://www.polyphaser.com/techdocs/Ufer%20and%20Tower%20Grounding.pdf

The Ufer tower base ground should only be used to supplement standard ground rods & radials.

And the current ARRL Antenna Books still recommend "minimizing the possibility of direct discharge path for lightning through the base."  I certainly don't consider ARRL books a definitive reference, but unless a ham understands the details of Ufer grounding, it's probably still good advice to follow.

Steve, W3AHL

Message: 5
Date: Fri, 12 Mar 2010 12:38:44 -0500
From: "Gary Schafer" <garyschafer at comcast.net>
Subject: Re: [TowerTalk] tower & antenna project questions
To: "'Tower and HF antenna construction topics.'"
<towertalk at contesting.com>, <wisecrafter at suddenlink.net>
Message-ID: <20100312173843.2913D1B60BDF at dayton.contesting.com>
Content-Type: text/plain; charset="us-ascii"

A Ufer ground is fine for a tower as long as it is not the only ground. You
still need ground rods outside of the tower base connected to the tower.

The J bolts for the tower mounting pad should be wired to the rebar inside
of the concrete. That is sufficient connection to the rebar for a Ufer
ground. You don't want any unconnected rebar gaps inside the foundation that
could arc.

73
Gary K4FMX

...snip...