Broadcast stations on medium wave use copper mesh around their tower
piers, extending out around 20 feet, in cases where the tower is
voltage fed, i.e. around 190 degrees. In those cases the v. at the
feedpoint can be a few thousand v. RF. For ham radio, 160 m.
verticals are almost always around 90 degrees long and current fed so
some kind of copper ring or strap around the radiator base with the
radials bonded to it is okay. The problem with aluminum is bonding
the copper to it in a way that doesn't involve a reaction. You'd
probably have to employ a physical bond using brass hardware.
Stainless Steel may not have that problem, but it is not anywhere near
as good a conductor.
73
Rob
K5UJ
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