http://forum.tvfool.com/showthread.php?t=901
Ideally, an outdoor mast would be connected to the electrical service ground using a #10 gauge copper wire (or larger)... the most effective ground connection is short and direct, if bends are needed, they are not sharp.
Ideally, the coax down-lead would be run close to the electrical service ground. There, a ground-block would be connected to the service ground using a #10 gauge copper wire (or larger).