The Universal Towers base consists of steel legs with locking
crossmembers (excuse my nomenclature) near the bottom and top of the
base so that those legs mostly load the concrete in compression in
either direction, up or down. Do not let those legs extend to the
bottom of the concrete, to retard corrosion.
A welded steel cage in the base can make the base a better lightning
ground. Look up Ufer ground. Rebar is good, if it is of a materiel that
can be welded and is welded with compatible welding material. It is
necessary to provide ample area (circumference times total length) of
the cage material and to distribute it correctly within the concrete. I
don't recall the exact details, but expect someone will add that to this
thread. I recall that my cage, in a 5' X 5' X 6' base is 4' square,
with 5 vertical members on a side and 4 vertical members internal to its
sides. This cage is tied into a lightning ground system system external
to the base. Connect it, external to the base, to the tower legs and to
a network of radials and ground rods to provide a low inductance (and
low impedance) lightning ground at the tower. Tie it with low
inductance members such as wide straps or parallel conductors to the
remainder of the ground system.
73 de WOØW
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