The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 213
is a negative one,the disc disappearing when this is to be done. 188 PRACTICAL TELEPHONE HANDBOOK Cord Circuit.—Fig. 215 shows the connecting cord andoperators connections, and it will be seen that when twosub-exchange lines are connected together by the two plugs,the speaking current is supplied… … Cord Cmcuir Fig. 215 annunciators being shunted by non-inductive resistances, R.R., so as not to interfere with the speaking. J unction-Line Connections.—Fig. 216 shows the connections of a junction line joining the sub-exchange to the main exchange, and it will be seen that each junction is…
Telephone
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