The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 198
by the raising of the jack springs from the inner springs. Thedrop of. the calling line serves as the ring-off or clearing signal,being connected as a shunt to the main loop-line circuit. Thedrops are wound to 1000 ohms, and, being of high inductance,they offer great impedance to the speaking… … Elevation Fig. 197 Fig. 198 line, the required number ascertained, and the plug with-drawn and plugged into the called-for line-jack. A ring is 174 PRACTICAL TELEPHONE HANDBOOK then given, and on an answer being obtained the plug of thecalled line is inserted into the jack of the calling line,…
Telephone
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