English: Antenna tower of AM radio station KBRC, located in Mount Vernon, Washington state, USA. It currently broadcasts on 1430 kHz with a power of only one kilowatt. This common type of broadcasting antenna is a quarter-wave "mast radiator"; the 200 ft (61 m) tower itself is connected to the radio transmitter and serves as the radiating element. The base of the antenna is supported on a sturdy ceramic insulator, which isolates it from the ground. The separate sections of the tower are tied together electrically at the joints by copper strips (visible at bottom) to ensure it is a continuous conductor. The supporting guy wires are insulated where they attach to the tower by porcelain strain insulators. The full antenna array consists of two identical towers, fed 55° out of phase to create a directional pattern.