540 



BELL SYSTEM TECHNICAL JOURNAL 



Suppose that at D — 1, i.e. 



Gs = GsxW~\ (10.14) 



In Fig. 51 ir~ has been plotted vs W. 



Now let us take an actual example. 

 {d = d\, (j> = oji) 



6 = 2 



G,a = .inyye 



Gs, = .()95/ye 



The information above has been used in connection with Figs. 51 and 52 

 and ratio of resonator loss to small signal electronic admittance, Gr/jc, 

 has been plotted vs IF in Fig. 53. A 2K25 oscillator operated at a beam 



Gr 



ye 



0.76 0.80 0.84 



0.88 092 0.96 1.00 1.04 



RELATIVE FREQUENCY, W ' 



Fig. 53. — Computed variation of ratio of resonator loss to small signal electronic ad- 

 mittance vs relative frequency W for certain resonator parameters assumed to fit the 

 characteristics of the 2K25. 



voltage, Fo , of 300 volts had a total cathcde current /d of 26 ma. This 

 current passed three grids on the first transit and back through the third 

 grid on the return transit. On a geometrical basis, h^^^ of the cathode 

 current should make this second transit across the gap. Th,us the useful 

 beam power was about 



Po = (.53) (300) (.026) = 4.1. 



If we assume a drift efifectiveness factor F of unity, then for tb.e 7| cycle 

 mode, the efficiency should be given by Um divided by 7f . //„, is plotted 

 as a function of Gn/y, in Fig. 7. Thus, we can obtain rj, the efficiency, and 

 hence the power output. This has been done and the calculated power 

 output is plotted vsIFin Fig. 54, where IF = 1 has been taken to correspond 

 to 9,000 mc. It is seen that the theoretical variation of output with fre- 

 quency is much the same as the measured variation. 



