On the Solution of the Problem of Night Effects with the Radio Range Beacon System

A new antenna system is described for use at radio range beacon stations which eliminates the troublesome night effects hitherto experienced in the use of the range beacon system. Considerable data, comprising ground and flight measurements, are given on both aural and visual type range beacons using the present loop transmitting antennas, which show, the severity of the night effects encountered. Because of the magnitude of these effects, particularly in mountainous country, the range beacon course often becomes of no value beyond about thirty miles from the beacon station. With the new antenna system developed, referred to as the transmission-line antenna system, the beacon course is satisfactory through its entire distance range, the night effects becoming negligible. Experimental data are given comparing the performance of the transmission-line and loop antenna systems under nearly identical conditions. The paper includes a theoretical analysis of the phenomena underlying the occurrence of night effects and how to eliminate them.