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BELL SYSTEM TECHNICAL JOURNAL 



of the AN/TRC-6 system. From this it can be seen that the sink margin is 

 approximately 2 at all frequencies. In a transmitter tube another factor, 

 which is of small importance in a beating oscillator, becomes of interest. 

 This factor is the {lulling figure, which is defined as the ma.ximum frequency 



FREQUENCY 



POWER 



Fig. 103. — Rieke diagram for the 2K54 at a nominal frequency of 4500 megacycles. 

 The point at the unity vsivr condition is obtained by adjusting the repeller voltage and the 

 back piston of the coupling of Fig. 101 to the values which gave maximum power. These 

 conditions were then held fixed for the remainder of the chart. 



excursion which will be produced when a VSWR of 3 db is presented to the 

 transmitter and the phase is varied over 180°. Fig. 107 gives the pulling 

 figure as a function of frequency for the 2K54 and 2K55. The requirements 

 on the pulling figure for the 2K54 and 2K55 were not severe, since in the 

 AN/TRC-6 system the tube is coupled to the antenna by a very short wave 

 guide run and, furthermore, the antennas are fixed. 



