VACUUM TUBES AS HIGH-FREQUENCY OSCILLATORS 103 



Although some progress has been made in the modification of con- 

 ventially designed water-cooled tubes for use above 100 megacycles, 

 more attention has so far been given to the development of radiation- 

 cooled tubes for this frequency range. 



A departure from conventional design with increasing frequency is 

 illustrated by a radiation-cooled tube described by McArthur and 

 Spitzer ^ in which the ratio of the plate diameter to the plate length 



Fig. 5 — A radiation cooled tube for use in the frequency range from 60 to 180 

 megacycles per second. Note the large ratio of the plate diameter to plate length 

 and the special arrangement of the leads. 



^ For all numbered references see list at end of paper. 



