The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 548
more serious defect is that the speaking circuit ofthe lines is rendered very poor by the inclusion of severalrelay magnets and wiper and switch contacts directly in themain lines. This is shown in Fig. 477, which shows the mainline connections when subscriber No. 2222 is speaking throughto No.… … 5 o i
Telephone
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