With new combined line-and-recording method, known as CLR all calls are routed to operators who must themselves be able to reach all outgoing toll lines; in larger cities, however, it is not possible to have all toll lines appear in multiple before each CLR operator, so that toll tandem board containing all toll multiple has been developed; board acts as central point in toll office through which operators may secure additional circuits.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Toll tandem switchboard


    Additional title:

    Bell Laboratories Rec


    Contributors:

    Published in:

    Publication date :

    1930


    Size :

    4 pages


    Remarks:

    4 Figs.


    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English




    3B toll switchboard

    Greene, J.C. | Engineering Index Backfile | 1939


    Toll switchboard no. 6

    Allison, S.W. | Engineering Index Backfile | 1947


    Modern switchboard practice

    Davis, H.P. | Engineering Index Backfile | 1902


    SWITCHBOARD INSTALLATION METHOD

    TANANO NAOYUKI | European Patent Office | 2024

    Free access

    Navy switchboard instruments

    Gillette, C.S. | Engineering Index Backfile | 1923