Abstract :
A transmitting radiotelegraphic set using a very short, rapidly rotating, quenching gap is described. It is shown that by using properly sectored sparking surfaces the partial discharges can be regularly spaced, and a higher note obtained in the receiver than corresponds to the frequency of the alternating current supplied. The construction of the set is given in detail. The generation of sustained radio frequency energy by similar means is explained. An audibility meter, which is a modified audio frequency telephone transformer with variable and measurable coupling between primary and secondary, is discussed. The author also outlines the development of a radio frequency wattmeter. The successful instrument, which is of the electrodynamometer type, is shown.
