616 



BELL SYSTEM TECHNICAL JOIRNAL 



voltage were made less negative. In other words, on the rise of each pulse 

 the situation is equivalent to that in a C'lT oscillator when, for a fixed 

 resonator voltage, one starts with a repeller voltage too negative to permit 

 oscillation and then reduces the repeller voltage until oscillation occurs. 

 Let us now suppose that the hysteresis is such that under these circumstances 





-5 



FREQUENCY 



POWER 



^ 



Fig. 105. — Rieke diagram for the 2K55 oscillator at a nominal frequency of 4800 mega- 

 cycles. The unity vsicr point was obtained as described in Fig. 103. 



the amplitude of oscillation would suddenly jump to a large value. We 

 would then obtain a variation of peak jjower output as a function of the 

 repeller voltage shown in Fig. 108. Ordinarily, the repeller voltage would 

 be adjusted so as to obtain maxmum power output as, for example, with 

 the repeller voltage V m ■ Next, let us sui)|K)se that a variable impedance 

 is presented to the oscillator with the repeller \'oltage held fixed at value 

 V R\ , as would be done, for example, in obtaining an impedance performance 



