Airborne automatic direction-finders

The paper is concerned with the use, in aircraft, of automatic direction finders of the switched-cardioid type. Operating principles are described, and the underlying design considerations are dealt with. Representative examples of German and American origin, used widely during the war, are described, and reference is made to a new equipment being developed. A section is devoted to new developments in connection with iron cored loops, and cathode followers for coupling the loop to the receiver. The more general aspects of continuous-wave (C.W.) direction-finding are treated only to the extent necessary to ensure completeness.