A Dual-Diversity Frequency-Shift Receiver

Major improvements have been made in radio-telegraph transmission over a period of years, but the improvement resulting from signaling by frequency shift instead of interruption of the carrier wave has been achieved in practice only recently. These matters are discussed, and associated with a number of references to other work in this field. A description is given of dual-diversity receiving equipment, employing audio-frequency filters for separation of "mark" and "space" signals. The equipment is intended for use on direct-printing, commercial telegraph circuits.