The Operating Characteristics of a Three Phase 500 Cycle Quenched Spark Transmitter

The attempt to produce a nearly continuous radiation of energy and high tone frequencies by the use of polyphase transmitters is historically considered. The work of Eisenstein and Seibt is described. Experiments with two and three phase transmitters were made; and it was found that the wave trains produced by successive discharges in adjacent phases overlapped in the antenna, thereby causing unmusical tones in the receiver and a diminution of transmitter efficiency. This decrease in efficiency is due to the increased reaction of the antenna on the closed oscillating circuits and the consequent disturbance of the regularly spaced spark discharges of the transmitters of each phase. By increasing the antenna damping, thereby lessening the overlapping of successive wave trains, the musical quality of the tone was improved and the transmitter efficiency markedly increased. Tests on dummy antennae and actual long distance tests were made. The production of practically sustained radiation, susceptible of reception by the use of the ticker or analogous devices, and produced by polyphase transmitters, is favorably considered. The limitation of quenched spark transmitter efficiency by the overlapping of rapidly successive wave trains is discussed.