1116 THE BELL SYSTEM TECHNICAL JOURNAL, OCTOBER 1951 



roiA. 



GETTER 



END SHIELD 

 MICA DISK 



PLATE 



CONVENTIONAL 

 SCREEN GRID 



MICA DISK 



FRAME GRID 



Fig. 9 — Cutaway view of the 435A. 



Figures 9, 10, and 11 are the cutaway views of the 435 A, 436A, and 43 7 A 

 tubes. The overall dimensions of the L3 tubes are: 



Conventional construction for small repeater tubes may be thought of as 

 two mica wafers between which are assembled the active elements of the 

 tube. The mica wafers serve to support and space the tube elements. This 



