said by John Galt:That should have been 4^3 feet or 64 cubic feet. I was typing without thinking said by bburley:
The manual for a DMX-68 wants 4 cubic feet of concrete.
Perhaps you mean yards...??
I also met someone who was concerned about concrete + lightning. He said that a direct hit could split the concrete and his solution was a rubber insulator around the concrete and a separate ground rod. At only 30 feet, I don't know if that is a concern.
This demonstrates a complete lack of understanding of the issues involved (not you...the other person).
The base needs a spot-welded rebar cage with a tail for a bonding jumper to the tower/grounding system.