RADIO SECTION 



Devoted to the Encouragement of Amateurs 



and Experimenters in the Field of 



Radio Communication 



Aeroplanes, Wireless and the War 



By William Dubulier 



The author of this article is an American radio engineer, who has performed exper- 

 imental work for the United States Government and ivhose investigations for the British 

 and Russian governments have attracted attention abroad. His wireless apparatus is 

 now used on British military aeroplanes. His article may therefore he considered as 

 an exposition of the subject of radio communication from aeroplanes from first hand 

 knowledge. — Editor. 



HE art of warfare has been trans- For aeroplane use, the instruments 

 formed by wireless and wireless must have a greater range. They vary 

 has in turn been transformed by in power from twenty watts to two kilo- 

 modern warfare. We can safely say 

 that the one great electrical event of the 

 war is the use of wireless even between 

 trenches, and the directing of artillery 

 fire. While the regular telephone and 

 telegraph are also used, the wires are so 

 frequently broken by shrapnel and shell 

 fire that wireless proves to be the only 

 uniform and trustworthy means of com- 

 munication. The men themselves at 

 night (the only time when they dare 

 leave the trenches) stumble over regu- 

 lar telephone and telegraph wires and 

 break them, and often there is no 



T 



watts, which latter is the power of the 

 instruments now being installed on big 

 aeroplanes made in England and em- 

 ployed not only to signal the hits and 

 misses of heavy artillery, but also to jam 

 the enemy's stations. 



In a wireless installation of this 

 aeroplane type, light weight and com- 

 pactness are the most important re- 

 quisites. Let us begin by describing the 

 small installations which require about 

 twenty watts to operate and which are 

 used almost exclusively by the French 

 army for directing artillery fire. In de- 

 opportunity to repair the damage. Not signing this instrument old principles 

 only have the Allies tried to get wire- were revived — principles quite the same 

 less trench sets, but the Austrians, Ger- as those in vogue when wireless first 

 mans and other powers as well. The came into being. There is a small in- 

 trench set in question is one in which duction coil with a vibrator and a 

 one man and certainly no more than two spark gap, and an aerial and ground or 



men are needed to 

 carry, set up and 

 operate. The trans- 

 mitting distance 

 need not be more 

 than five miles. 

 Such instruments 

 are now being 

 built and supplied. 

 One type weighs 

 only eight pounds. 



Fig. 1. Wiring diagram of the Rouzet 



system, showing synchronized revolving 



spark gap now being used by English 



and French governments 



295 



counter capacity 

 connected across 

 the secondary. This 

 is shown in Figure 

 1. The efficiency is 

 greatly increased 

 by connecting the 

 condenser across 

 the interrupter and 

 primary as in the 

 Dubilier system in- 



