. The Bell System technical journal . e of this a transducer was developed into which the tube could beplugged. This is shown in Fig. 101. The central chuck the centerconductor of the output ot tiu tube into the guide. It had been REFLEX OSCILLATORS 613 originally intended to design this transducer so that all elements would befixed. It was found, however, that an adjustable back piston setting per-mitted compensation for manufacturing tolerances in the tubes as well aspermitting the presentation of a better impedance to the oscillator over theband than was attainable with a
. The Bell System technical journal . e of this a transducer was developed into which the tube could beplugged. This is shown in Fig. 101. The central chuck the centerconductor of the output ot tiu tube into the guide. It had been REFLEX OSCILLATORS 613 originally intended to design this transducer so that all elements would befixed. It was found, however, that an adjustable back piston setting per-mitted compensation for manufacturing tolerances in the tubes as well aspermitting the presentation of a better impedance to the oscillator over theband than was attainable with a fixed transducer. This is illustrated inFig. 102 which shows the power output versus frequency for a typical 2K54and a typical 2K55 as a function of frequency for three cases. In one case,as shown by curve B, the power output is delivered at all frequencies intothe optimum impedance, the impedance into which the oscillator willdeliver maximum power. Curve A shows the power output delivered into ■REQUIRED RANGE - REQUIRED RANGE. 4200 4300 4400 4500 4600 4700 4600 4900 FREQUENCY IN MEGACYCLES PER SECOND fig. 102.—Peak power output vs frequenc\- for the 2K54 and 2K55 oscillators for sev-eral load conditions. Curves A give the performance obtained when the tubes operateinto a characteristic admittance load threugh the coupling of Fig. 101 with the end platefixed so that the admittance presented to the tubes is constant to within 1 db over thefrequenc}- range. Curves B give the performance obtained when the optimum imjjedanceis presented to the oscillators throughout the band. Curves C give the performance ob-tained when the tubes are coupled to a characteristic admittance load with the couplingunit of Fig. 101 and with a back piston adjusted to the best value at each frequency. a transducer which has the back piston fixed at a distance from the probe,so chosen that the impedance seen by the oscillator is fiat over the band towithin 1 db. Curve C shows the power output when
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
