Total posts : 45366
1. Yes, the radial system is as good as the ground rod. The radials act as an “artificial” ground or “counterpoise.” The transmitter should be mounted as close to the center of the radial system as possible, and the base of the vertical antenna mounted just above the radial system.
2. If you have a ground connection available on the roof, like water pipes to/from air conditioning, connect the center of the radial system to that.