The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 196
(No. 3), (which isconnected as a shunt), tofall, and the operatorthereupon restores thecalling-line plug (No. 1) toits normal position. Thedrops are as shown inFig, 159, and are woundto 1000 ohms resistance. Single-Cord Boards.—Figs. 197 and 198 show a 6-lineswitch-board of a much-used type, and… … 172 PRACTICAL TELEPHONE HANDBOOK latter are connected to the inner springs of the jacks. Theshort outer springs are also connected to the plug-tip strandof the connecting cord, and the long spring to the sleevestrand of the cord. Each line has thus a connecting cord andplug permanently joined, and…
Telephone
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