The Shure UA870 is an active UHF wireless directional antenna. It features a log periodic dipole array. When compared to an omnidirectional 1/2-wave antenna, the cardioid pattern provided by the UA870 offers enhanced reception of the desired coverage area and greater rejection of RF signals outside the coverage area. To compensate for coaxial cable signal loss, the UA870 has an on-board amplifier that offers user selectable 3 or 10 dB gain. The gain setting is indicated by two LEDs. Remote 12 Vdc power for the antenna amplifier is provided by a Shure U4S, U4D, ULXP, ULXS, UR4S and UR4D Receiver or a Shure UA845 or UA844 Antenna Distribution System through the connecting coaxial cable. The UA870 can be mounted on a microphone stand, suspended from the ceiling, or mounted to a wall using the integrated swivel adapter bracket. The UA870 is weather resistant for use outdoors. For best diversity performance, use two UA870 antennas.