http://forum.tvfool.com/showthread.php?t=901
http://forum.tvfool.com/showpost.php...4&postcount=20
Ideally, run the coax to a location near your home electrical service ground rod (usually near the service meter) and install the ground block there. The total wire length between the coax grounding block and the service ground is best kept short, 10 feet or less.
Also, I would verify the mast is grounded with a low resistance conductor (#10 AWG or larger) the goal is to be able to carry a large current if there's ever a fault, that will keep voltage differences low even if there's a problem. Soil is often a very unreliable conductor. Copper wire is a 'known quantity' conductor that can be relied in far better than soil.