First off, it's a 150' tower in parallel with 135 feet of coax.
Insofar as #6 vs strap. There are three factors: surface area
[the grounding system's surface area must equal or, preferably,
exceed the circumference of ALL the cables and/or waveguides
attached thereto], skin effect, and inductance. Two 8'-long #6
wires will have half the inductance (and voltage drop) of one
wire alone, 3.4uH vs 1,7uH with Vd's of 8.2kV and 4.3kV
respectively, and be slightly better (0.1uH) to the value for the
one 6"-wide strap of equal length. In that respect you're
correct. However, those two #6's will suffer from the first two
issues and is akin to having a four-lane asphalt highway suddenly
become a one lane dirt road. Therefore, more surge energy could
get into your equipment. Remember that the PolyPhaser coax
protector is dumping the surge energy on the center conductor to
this ground system as well.
The primary issue is inductance, but our bulkhead grounding
systems come with two 6"-wide straps, which of course is far
better than two #6's. I have been to many commercial sites where
they use but one #6 or #2 for the ground path. Our main point is
that the cables should come to the very bottom of the tower
before heading over to the building. In this respect, hams are
usually "better" than the commercial folks.
Hope this helps!
Sincerely and 73,
Bob Wanderer AA0CY
Senior Applications Engineer
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