130 



BELL SYSTEM TECHNICAL JOURNAL 



■D 60 



48 z 



32 § 



10 15 20 25 30 35 40 45 50 



LENGTH OF TUNING SYSTEM IN CENTIMETERS 



Fig. 30— Relation of wave-length and output to length of tuning system in mag- 

 netron oscillator of second type. Anode potential — 2000 volts, Magnetic field — 

 254 gausses. 



is shown in Fig. 31, and the dependence of frequency on the current in 

 the magnetic field coil in Fig. 32. The importance of the adjustment 

 of the field angle is shown by the data in Fig. 2^?^. 



An output of 2.5 watts at 3160 megacycles has been reported by 

 Wolff, Linder, and Braden." They find that the efficiency of the tube 

 is much improved by using end plates in place of the tipped magnetic 

 field. Cleeton and Williams ^i have been able to obtain oscillations at 

 30,000 megacycles with a magnetron tube. 



Amplification 



The use of the conventional thermionic triode as an amplifier greatly 

 exceeds its use as an oscillation generator in communication applica- 

 tions. Its ability to amplify has contributed much more to the de- 

 velopment of our present-day long distance communication, whether 

 by wire or by radio, than has its ability to oscillate. The complete 

 utilization of ultra-high frequencies as carrier channels in communica- 



