290 



BELL SYSTEM TECHNICAL JOURNAL 



the position of the piston closing one or both of the ends of the wave 

 guide. In the case of diode No. 37 the wave-length was found to vary 

 over a range between 11.50 and 11.65 cm. with plate voltage and over 

 a range between 11.52 and 11.56 cm. with piston position. 



0.30 

 0.E8 

 0.26 



0.24 



If) 



H 0.22 



!5 

 5 



2 0.20 



3 0.18 



(- 



0.16 

 a: 



UJ 



1 0.14 

 Q. 



0.12 

 0.10 



O 0.20 



y 0.16 



240 260 260 300 320 340 360 360 



PLATE VOLTAGE 



Fig. 7 — Power output and plate efficiency for diode no. 24. 



In conclusion, the writers wish to mention the work done by Mr. 

 C. A. Bieling of the Bell Telephone Laboratories in working out suitable 

 mechanical design features and in the actual assembly and processing 

 of tubes which were built and tested. 



