. The practical telephone handbook and guide to the telephonic exchange . Fig. 151a.—Three Extension Instruments without Intercommunication bell fitted in connection with the extension instrument. Forthese bells an extra line is needed between the main andeach of the extension instruments, These bells are wound to100 ohms resistance. SWITCHES AND EXTENSION INSTRUMENTS 138a Any one of the stations may call the exchange by merelyraising the receiver so as to close the loop circuit, but thespeaking may be overheard by any one of the Fig. 152.—Connections for Exchange and Extension Inst
. The practical telephone handbook and guide to the telephonic exchange . Fig. 151a.—Three Extension Instruments without Intercommunication bell fitted in connection with the extension instrument. Forthese bells an extra line is needed between the main andeach of the extension instruments, These bells are wound to100 ohms resistance. SWITCHES AND EXTENSION INSTRUMENTS 138a Any one of the stations may call the exchange by merelyraising the receiver so as to close the loop circuit, but thespeaking may be overheard by any one of the Fig. 152.—Connections for Exchange and Extension Instrument—with Secrecy It will be noticed that only one condenser and one inductioncoil is used for the three instruments. Fig. 151a gives the connections of an arrangement for thesame purpose in which each instrument is provided with its
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
