[GroundUrMast]

So far as I am aware, the NEC and similar codes would allow the grounding and bonding conductors to be run in and through the building. I choose not to do that with the antenna system ground because I'm uncomfortable with the idea that the energy of a direct lighting strike would be directed into or though my house intentionally.

I prefer to to keep the mast and coax grounding connections separate until they meet at the ground rod or similar connection to the electrical service ground. The goal I have in mind is to keep the length of wire that serves the coax grounding block as short as possible. This will provide the lowest voltage drop possible if fault current flows in the coax. I don't want to share this grounding conductor with the mast in case the mast is energized... Any voltage drop in the mast conductor could then cause fault current or at least impose voltage in the coax runs if the mast and coax grounds shared a common grounding conductor. As the coax ground block is located further from the electrical service ground (along the mast grounding conductor), the resistance of the ground wire increases, as a result, the magnitude of the voltage drop due to fault current increases. Shared grounds means you will share faults.

In the case where I added a ground rod, I used #6 AWG copper to permanently join the new rod to the existing electrical service grounding system. The newly installed rod was then an integral part of the 'electrical service grounding system and located much closer to the antenna mast than any other part of the electrical service, so that was the location I chose to mount the coax grounding block.

It's entirely possible that the #6 AWG will have a significant voltage drop if current from an antenna system fault occurs, but I think it's reasonable to expect the weakest link to fuse open first in the event of a catastrophic event such as a direct lighting strike. Ie., the coax should fail first, then the #10 AWG... the #6 AWG should last the longest. If I've kept all those conductors outside, I can sleep well knowing I've taken what I think are reasonable steps to direct potentially destructive energy outside rather than into my house. I don't hope to prevent any and all damage if I do get a direct lightning strike, but rather, if my antenna system fails, it should fail 'safe'.