(under subclass 111) Subject matter wherein the electronic tube is of the type wherein the electric space discharge takes place between electrodes which are exposed to the atmosphere.
(1) Note. This type of electronic tube is usually called a spark gap or an arc device.
SEE OR SEARCH CLASS
313, Electric Lamp and Discharge Devices, appropriate subclasses for the structure of spark gaps and open air arc devices.
315, Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to electronic tubes of the type which have the gap in the open atmosphere.
331, Oscillators,
127, for oscillators using a gaseous space discharge device of the spark or open arc type, and which convert direct current to oscillatory current.
