A HIGH POWER VACUUM TUBE 17 



The filament leads are of copper red one eighth of an inch in diameter 

 and are sealed through 1" copper disc seals. The grid is of molyb- 

 denum and is wound around three molybdenum supports. 



The handling of the parts of this tube during manufacture presents 

 a task of no mean magnitude and numerous fixtures have been devised 

 to assist in the glass working. It has been found necessary for in- 

 stance to suspend the anode in gimbals during the making of the tube 

 seal owing to its great weight, and special devices have been made 

 to hold the filament grid assembly in place while it is being sealed in, 

 otherwise the strains produced by its weight cause cracking of the seal. 



The significance of this development in the radio art cannot be 

 overestimated. It makes available tubes in units so large that only 

 a very few would be necessary to operate even the largest radio sta- 

 tions now extant, with all the attendant flexibility of operation which 

 accompanies the use of the vacuum tube. 



From the standpoint of wireless telephony the development of these 

 high power tubes gives us the possibility of using very much greater 

 amounts of power than have ever been readily available before. The 

 filaments in these tubes have been made so large that the electron 

 emission from them will easily take care of the high peak currents ac- 

 companying the transmission of modulated power. 



The 100 k. w. tube by no means represents the largest tube made 

 possible by the present development. There is no doubt that if the 

 demand should occur for tubes capable of handling much larger 

 amounts of power they could be constructed along these same lines. 



