16 



BELL SYSTEM TECHNICAL JOURNAL 



The success which had attended the development of a tube of this 

 high power capacity indicated the possibility of constructing still 

 larger tubes and it was decided to proceed with the development of a 

 tube capable of delivering at least 100 k. w. into an antenna. 



The development proceeded with a few minor alterations along the 

 lines of the smaller tube, nominally rated at 10 k. w. and the 100 k. w. 



1-lG. 11 



tube as now developed is shown in Figs. 10 and 11. The anode which 

 is made of a piece of seamless copper tubing closed by a copper disc 

 welded into the end, is 14" long and 3.5" in diameter. The filament is 

 of tungsten and is .060" in diameter and 63.5" long. The current 

 required to heat it is 91 amperes and the power consumed in it 6 k. w. 



