If all of the grounds are not bonded together, you can get very large
voltage differences which are every bit as much a problem as the direct
current strike of the bolt.
It is fine to have a very good ground on a tower to help dissipate charge
buildup, but having conductors to all the grounds insures the charge does
not develop differences in voltage between say the telephone ground point
and the electric lamp ground next to your phone, causing an arc over. Of
course, there will still be voltage drop along the bonding conductors but
much less than relying on the soil path alone.
Engineers have spent years in labs and chasing lightning in the field to
develop current bonding theory which is represented by the application notes
on the PolyPhaser web site.
-Stuart
K5KVH
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