(under subclass 24) Coupling systems having a long line with a coupling network at each opposed ends of the long line.
(1) Note. Where the long line is merely a part of a coupling network, and does not link two different coupling networks together, classification is not in this subclass. See subclasses 156+ for this type of delay network, subclasses 50+ for this type of impedance matching network, 202+ for this type of wave filter.
(2) Note. In this subclass are systems having two coupling networks with a long transmission line connected to transmit energy from one network to the other. These systems approach a complete system. For example, a 70 ohm source connected by a network to a 300 ohm line which is coupled by a network to a 150 ohm receiver. At each point of connection there would be a coupling network.
SEE OR SEARCH THIS CLASS, SUBCLASS:
50+, see (1) Note above.
156+, see (1) Note above. 202+, see (1) Note above.
236+, for long lines, per se.
SEE OR SEARCH CLASS
178, Telegraphy, appropriate subclasses where the system is limited to code signaling other than telephony.
53+, for amplifier systems combined with long lines or long line elements wherein such means furnish a coupling means for the amplifier.
379, Telephonic Communications,
90+, for composite telephone systems (e.g., combined power and telephone circuit) and subclasses 338+ for two telephone lines with two-way repeaters at spaced points along the line.
381, Electrical Audio Signal Processing Systems and Devices,
82+, for public address and similar systems (e.g., a microphone and a line, or a line and a reproducer such as a loudspeaker or a microphone, a line and a reproducer).