Experimental Electricity 



Practical Hints 

 for the Amateur 



Wireless 

 Communication 



The Construction of an Improved 

 High-Tension Audion Battery 



By Charles Horton 





IN the early days when the audion as 

 a detector was used only to a limited 

 extent, it was generally considered 

 that on account of the extremely high re- 

 sistance of the path 

 througii the telephones 

 and across the vacuum in 

 the bulb, the high-tension 

 battery used to supply 

 this circuit must be good 

 for many years' work. 

 But since the audion has 

 been manufactured and 

 placed on the market and 

 its use has become wide- 

 spread, it has been found 

 that sometimes the dry cells used for 

 the high-tension battery suddenlj- seem 

 to lose their voltage in a most unaccount- 

 able way and have to be renewed. 



therefore, it becomes necessary to test 

 each cell of the high-tension battery, 

 which is a tedious job; and, since the 

 terminals of the cells are usually soldered 





Fig. 2. Two other views of the switch arrangement 



to their leads, the replacing of one or 

 more cells is a lengthy and unpleasant 

 operation. In order to make the cells 

 easily accessible, it is now customar>' to 

 mount them in a bo.v separate from 

 the audion proper, this bo.x ha\'ing on 

 one panel the usual high-tension switch 

 and two binding posts from which 

 wires lead to two other posts on the 

 audion cabinet. 



Fig. 1. Showing the arrangement 

 switches on the case 



of 



It has been noted by many e.vperi- 

 menters that only certain of the cells 

 become "dead" while the others are 

 apparently as good as when installed. 

 When the audion set refuses to work. 



! (S& r& iSk A r A ! 



* 



Fig. 3. View of the case with the front 

 panel removed 



l."?! 



