X510HDN X510 HDN X510HD N X-510HDN Original Diamond Antenna 144/440 MHz Base Antenna N-Type Connector. Diamond Antenna X510HD Series Base Station Antennas are also one of their best repeater antennas. They are pre-tuned to achieve maximum gain in both the 2 meter and 70 centimeter amateur bands and have a wide frequency bandwidth. Features include a heavy-duty fiberglass radome, overlapping outer shells for added strength, stainless steel mounting hardware and radials, and waterproof joint couplers. If you are in the market for a rugged base/repeater antenna, Diamond Antenna X510HD Series Base Station Antennas have you covered. Mast clamp hardware included.