TREA

Manual exchanges

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Industry

  • CPC
  • H04M5/00
This industry / category may be too specific. Please go to a parent level for more data

Parent Industries

HELECTRICITY H04Electric communication H04MTELEPHONIC COMMUNICATION

Current Industry

H04M5/00Manual exchanges

Sub Industries

H04M5/02Constructional details H04M5/04Arrangements for indicating calls or supervising connections for calling or clearing H04M5/06affording automatic call distribution H04M5/08using connecting means other than cords H04M5/10using separate plug for each subscriber H04M5/12Ringing or otherwise calling substations H04M5/14Applications of speech amplifiers H04M5/16with means for reducing interference with means for reducing effects due to line faults H04M5/18Arrangements for signalling the class or number of called or calling line from one exchange to another H04M5/20Number-indicating arrangements for incoming lines
Industries