. The Bell System technical journal . oped for the gain stage of the amplifieris a pentode with indirect heater. The heater requires a potentialof 10 volts and a current of ampere and the plate 150 volts. Thetube in the power stage is similar in type but requires a heater currentof ampere at 10 volts. With this power tube a feedback of about40 db has been found to provide a satisfactory reduction of inter-channel modulation.^ Both tubes were designed to have long lifewith very reliable performance. Description of Amplifier Each repeater comprises two amplifiers of the type illustrate
. The Bell System technical journal . oped for the gain stage of the amplifieris a pentode with indirect heater. The heater requires a potentialof 10 volts and a current of ampere and the plate 150 volts. Thetube in the power stage is similar in type but requires a heater currentof ampere at 10 volts. With this power tube a feedback of about40 db has been found to provide a satisfactory reduction of inter-channel modulation.^ Both tubes were designed to have long lifewith very reliable performance. Description of Amplifier Each repeater comprises two amplifiers of the type illustrated inFig. 8. A schematic diagram of the amplifier circuit is shown in 92 BELL SYSTEM TECHNICAL JOURNAL Fig. 9. Three stages with impedance coupling are used and the feed-back circuit is connected between the plate circuit of the last tube andthe grid circuit of the first. The amount of gain and the slope of thegain-frequency characteristic are controlled by the condensers andline equalizer in the feedback circuit. EQUALIZERIN FEEDBACK. TUBE-TESTINGJACKS GAIN-REGULATORCONDENSERGAIN-CONTROLCONDENSER REVERSIBLE SYNCHRONOUS RECEIVER MOTOR DIAL INDICATESPOSITION OF REG-ULATOR CONDENSER Fig. 8—Line amplifier. RECEIVERMOTOR
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
