A Combined Kenotron Rectifier and Pliotron Receiver Capable of Operation by Alternating Current Power

A new type of four-element tube is described, which combines the functions of kenotron rectifier and pliotron, and can be operated from an alternating current source of power without either "A" or "B" battery. The cathode is an equipotential surface so that alternating current hum is inappreciable even with three stages in series. The combination of equipotential cathode and large cathode area results in unusually high amplification and detection constants, making the tube a practical radio-frequency amplifier.