Abstract :
THE navigation of airplanes in fog or under conditions of low visibility is becoming more and more dependent upon the use of directional radio devices. As used in the United States, directional radio equipment takes 2 forms: (a) the directive range beacon used on the established airways, requiring no directional radio equipment on the airplanes using the service, and (b) the direction finder, used on airplanes engaged in cross-country flying independent of the airways. The use of the direction finder on airplanes has not been extensive. There has, however, been increasing demand for a direction finder designed specifically for airplane use. The U.S. Bureau of Standards, in its capacity as the research division of the aeronautics branch of the department of commerce, has developed a simple direction finder for this purpose. The following description is quoted in full from U.S. Bureau of Standards Technical News Bulletin for August 1933. p. 83–4.
