Unofficial Alpha Subclasses: R A B C D E F G H K M N P Q J S T TS
DEFINITION
Classification: 178/70
(under the class definition) Means whereby the relay, sounder, or recorder on the opening and closing of another circuit with which it is suitably connected is caused to repeat the signals received into another line or circuit. Repeaters of this subclass establish direct communication between distant stations or connect branch and main lines and operate in but one direction at a time and require the services of an attendant for changing the direction of the operation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
56, for repeaters adapted to quadruplex telegraphy.
SEE OR SEARCH CLASS
330, Amplifiers, appropriate subclasses for amplifiers of various types, particularly
61, for those operating on the principle of the microphone.
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, appropriate subclasses for electromagnetically operated circuit controllers generally, and
220+, for electromagnets with armatures.
340, Communications: Electrical,
291, for signal box system repeaters, such as those which repeat signals arriving at a central to a plurality of fire houses.
361, Electricity: Electrical Systems and Devices,
236+, for speed controlled systems, subclasses 139+ for electromagnetic device control circuits, and subclass 211 for nonelectromagnetic relay control circuits.
375, Pulse or Digital Communications,
211+, for pulse repeaters.
379, Telephonic Communications
338+, for two way repeaters, specific to telephone work and usually operating on the principle of the microphone by varying the renewal current by variable contact pressure.
