The ALP690 is a high-performance active/passive UHF directional antenna with built-in RF amplifier for use with wireless microphone receivers or base station transmitters. The antenna is powered by DC bias inserted on the coaxial cable. When no bias is applied, the ALP690 automatically switches via relays to function as a passive antenna.RF amplifier gain, filter bandwidth and display brightness are adjusted with a membrane switch keypad and LED display on the control panel. RF gain is adjustable in 1 dB steps from -6 dB to +12 dB to match the RF loss depending on the type and length of coax cable in use. When used as an active antenna, the filter bandwidth is adjustable from 470 MHz at the lower end to either 608 or 700 MHz at the top end, to serve users needs in various markets and locations. Vertical orientation provides a wide horizontal coverage pattern.Main Features:Broad bandwidth for multi-channel systemsDirectional pattern with 4 dBd RF gainBuilt-in RF amplifier with adjustable gain for offsetting cable lossKeypad and membrane switches with LED readout for quick setupAutomatically switches to passive mode when no DC power is present on the coaxial cableDurable finish and weather tolerant construction for indoor/outdoor useSkeletal structure reduces wind loadingVersatile mounting options with the supplied mount and optional mounting adapter kitSpecificationsPattern Gain:+7 dBi (isotropic)+4 dBd (over dipole)Passband:Passive: 450 – 850 MHzActive: 470 – 608 or 470 – 700 MHz, selectableRF Amplifier Gain Range: -6 to +12 dB in 1 dB stepsThird Order Intercept: +27 dBm @ input; +41 dBm outputWeight: 13 ozs.; 355 gramsPower Requirements: DC bias on center pin of coaxial cable; 8V to 16V DC; 1.5 W max.; polarity protected