A single four-foot ground rod, driven into the ground no more than 12 inches from the base
A ferrite-core RF choke connected between the tower and ground
A connection between the tower base and a cold-water pipe
Separate eight-foot ground rods for each tower leg, bonded to the tower and each other✓الإجابة الصحيحة
الشرح
Effective tower grounding needs low impedance to earth and no potential difference within the structure, so each leg gets its own full-length ground rod and all rods are bonded to each other and to the tower. A single short rod or a cold-water pipe connection does not provide an adequate surge path.