The Marconi Four-Electrode Tube and Its Circuit

The paper deals firstly with the early forms of quadrodes or four-electrode tubes and leads up to a complete description of the Marconi type of quadrode or F. E. I. type and the attendant amplifier circuit. The amplifier described utilizes one F. E. I. tube and effects a one-stage radio frequency, a rectification, and a one-stage audio frequency. Information is detailed as to the practical experience obtained with this amplifier and quadrode, this particular combination now being a commercial issue to ships the radio installations of which are controlled by the Marconi International Marine Communication Company.