The voltage of the power supply is not listed(on radio or power supply which I wired directly into the back of the radio). There is a reference to 3Volts on the body of the radio(battery back-up?), but I find it hard to believe such a large "brick" is supplying such a low voltage. Other similar units are in the 5 to 12Volt range. The manual supplies no info. Info on brick is ---"cRUs" then E312169 then AD48-0100