ACT-311B is EIA standard 1/2U metal receivers. Receiver provides bias for booster where MIPRO antenna systems can be added for extended receiving range and stability. Backlit LCD displays group, channel, frequency, RF level, antenna selection, AF level, battery level indicator, interference warning indicator, and panel lock indicator. A lit green light indicates a working mode when receiver detects an incoming signal or buttons touched. Light dims automatically when receiver is idle for about 10 seconds. Balanced XLR / unbalanced 1/4inch audio output jack, output level switch and DC input are on the rear panel. One mixed-output switch is available for dual-channel receivers. High efficiency and low spurious PLL circuitry with Auto Scan functioin. Each receiver is presets with 11 groups, Groups 1~6, 7~10 have 8 &16 compatible channels respectively. Up to 8 channels in group 11 can be saved and recalled within 961 user-defined frequencies. A total of 112 preset channels per band. World’s first ACT™ function provides precise and rapid frequency sync to the transmitters. Advanced diversity technology for optimum reception range and reduces signal dropouts and the “PiloTone & NoiseLock” dual-squelch circuits prevent noise interference. Adjustable ‘SQ’ for higher sensitivity to increase receiving distance and lower sensitivity to reduce interference. Industry’s only RF interference warning indicator for ideal SQ level adjustment. DC input socket accepts 12~15V power supply. Matching ACT-32H handheld and ACT-32T bodypack transmitters.