Turning on the PowerPress and hold [VOL/PWR] control at the base.NOTELow-Voltage/High-Voltage AlertThe PRO5050 can operate on 12VDC (13.8V) or 24VDC (27.6V) powersupply, with the range between 10.2VDC to 28.8VDC.If the power supply voltage exceeds 28.8VDC, an alert tone sounds andHI DC flashes for 5 seconds. The power source must not exceed 32VDCotherwise permanent damage may occur to your radio, which may not becovered by the manufacturer’s warranty.If the input voltage falls below 10.2VDC, LO DC flashes for 5 seconds. Thepower turns off automatically if voltage falls below 9.0VDC.Switch your PRO5050 OFF and disconnect it from the power source, beforelocating the cause of the power supply problem.Operation14UNIDEN PRO5050 AM-CB TransceiverSetting the VolumeTurn the volume control at the base.