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Modern Central Office of Bell Telephone, #1
Thousands of relays form veritable canyons of equipment in the modern central office. At this section, customers' lines are connected into the circuits at the plant on Douglas Street, or re-routed when a subscriber moves so that the subscriber may…
Modern Central Office at Bell Telephone, #2
Power supply for the equipment contained in the central office is supplied from this three section rectifier panel in the basement of the building. The panel is also used to re-charge banks of batteries
Crossbar Central Office at Bell Telephone
When trouble develops in a crossbar central office, the equipment at the master test panel detects it, and will, upon the proper operation, produce a punched card giving the location of the trouble, the number called and the number calling, with the…
Telephone Equipment at Bell Telephone, #1
Dial pulses, which activate switching equipment, also produces punches on paper tape, indicating the calling number and the answer and disconnect times, for billing purposes.