Page:Popular Science Monthly Volume 88.djvu/323

 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

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��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-

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