The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 487
Fig. 434.—StandardCondenser … Fig. 435.—Rymer-Jones Discharge Key to thoroughly discharge the instrument before use. An instru-ment of a capacity = 05 microfarad is a very convenient size.Rymer-J ones Discharge Key.—A very good form of dischargekey is shown in Fig. 435. Two brass levers with longinsulating handles are pivoted…
Telephone
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