766 THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1953 



5. Spangenberg, K. R., Vacuum Tubes, p. 601. (McGraw-Hill). This reference 



covers essentially the same material as Reference 4. 



6. Reference Data for Radio Engineers, Third Edition, p. 121, Federal Telephone 



and Telegraph Corp. Here a universal chart of the selectivity (transfer 

 characteristic) of two coupled tuned circuits is presented. The format and 

 choice of variables of this presentation has inspired the selection of the 

 equivalent quantities applying to the driving point properties of coupled 

 tuned circuits. 



7. Harmen, W. W., and J. H. Tillotson, Beam-Loading Effects in Small Klys- 



trons. I. R. E., Proc, p. 1419, Dec, 1949. Equation (3) of this reference is 

 identical with equation (4.1) and has been used in the experimental de- 

 termination of the primary operating Q. 



8. Reed, E. D., A Sweep Frequency Method of Q Measurement for Single-Ended 



Resonators. Proc. National Electronics Conference, Vol. VII, p. 162. Also 

 reprinted as Bell Telephone System Monograph 1953. This method of Q- 

 measurement was used in the calibration of the secondary resonator de- 

 scribed in Section 4.3.2. The coupled resonator reflex klystron provides a 

 useful tool for this type of measurement as may be seen from Fig. 22(b). 



9. Albersheim, W. J., Measurement Techniques for Broad-Band Long-Distance 



Radio Relay Systems. I.R.E., Proc, p. 548, May, 1952. Figs. 4(a) and 4(b) 

 of this reference give the block diagram of a "Linearity-Test-Set" developed 

 at Bell Telephone Laboratories to determine the modulation linearity of a 

 reflex klystron used as FM-deviator. 



10. Boehlke, P. G., and F. C. Breedan, External Cavity Klystron. Electronics, 



p. 114, July, 1947. This paper gives an account of the design considerations 

 which led to the development of the 6BL6 reflex klystron. It also contains 

 useful information on its performance characteristics. 



11. Garrison, J. B., A Qualitative Analysis of Hysteresis in Reflex Oscillators. 



Radiation Laboratory Report No. 650, dated Feb. 4, 1946. In this treatment 

 on the causes of electronic hysteresis Garrison shows (on page 5) that a 

 dependence of the phase angle of the electronic admittance upon the magni- 

 tude of RF gap voltage will give rise to asymmetry in the mode plot of 

 power output vs. repeller voltage although the power vs. frequency rela- 

 tion will be symmetrical. (Note that the experimental mode plots for 

 QA; = of Figs. 20(a) and (c) show evidence of the same phenomenon.) 



