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BELL SYSTEM TECHNICAL JOURNAL 



Since the operating voltage is found to increase with increasing current, 

 oscillation at a constant anode current takes place along a line, such as the 

 Slater line for example, lying slightly above and parallel to the Hartree 

 line (see Fig. 16). The separation of the operating line from the Hartree 

 line increases with increasing DC current. 



O 60 



20 - 



2000 3000 4000 



MAGNETIC FIELD, B,IN GAUSS 



6000 



Fig. 16. — A V-B plot for a magnetron having eight resonators (see footnote 16) showing 

 the cut-off parabola and Hartree lines for several rotating field components. The ranges 

 of DC voltage and magnetic field have been extended considerably beyond values ever 

 applied to such a magnetron to show the lines for the fundamentals of all of the modes. 

 The typical operating point plotted is that specified in footnote 16 and plotted in Fig. 17. 



The necessary conditions for oscillation discussed above have been of 

 great value in the identification of the modes of operating magnetrons and 

 as the starting point in the design of new magnetrons for given wavelength, 

 magnetic held, and voltage. 



4.2 The Perjormance Chart: Another fundamental performance char- 



