a device for converting direct current power into high-frequency electromagnetic oscillations by means of an arc discharge through a gap that is connected in parallel with a circuit containing a capacitor and an induction coil. Oscillations are generated and maintained in the oscillatory circuit, which is made up of the elements mentioned above. The keying of the oscillations to send telegraph signals is achieved by short-circuiting turns on the induction coil in the oscillatory circuit. Because of serious disadvantages, such as frequency instability of the oscillations, the arc generator was replaced by high-frequency machine generators and later by vacuum-tube generators.
IU. V. LIUBCHENKO