9 Vdc 300 ma. Terminates with a 1.3 mm co-ax plug. Center positive.
A Note on Wall Transformers: A.C. and D.C. Wall Transformers are not regulated unless otherwise stated. They provide a specified voltage at a specified load. If the load is lower than specified, the voltage will be higher then specified. With a higher load, the voltage will drop below that specified. For example, a 12 volt 500 ma. wall transformer may read 20 volts with no load or 9 Volts with a 600 ma. load.