Manual exchanges

Classification Context

Section:

ELECTRICITY

Class:

ELECTRIC COMMUNICATION TECHNIQUE

Subclass:

TELEPHONIC COMMUNICATION

Child Classifications

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• H04M 5/02 Constructional details
• H04M 5/04 Arrangements for indicating calls or supervising connections for calling or clearing
• H04M 5/08 using connecting means other than cords
• H04M 5/1 using separate plug for each subscriber
• H04M 5/12 Calling substations, e.g. by ringing
• H04M 5/14 Applications of speech amplifiers
• H04M 5/16 with means for reducing interference; with means for reducing effects due to line faults
• H04M 5/18 Arrangements for signalling the class or number of called or calling line from one exchange to another