Low-Frequency Radio Receiving Measurements at the Bureau of Standards in 1931 and 1932

This report gives the monthly and annual averages of field intensities of ten European and three American low-frequency transatlantic radio stations, between frequencies of 16 and 24 kilocycles, and the field intensity averages of atmospherics on 15 and 23 kilocycles, observed at the Bureau of Standards, for the years 1931 and 1932. Measurements were made by the telephone current comparison method. Annual average curves of daylight field intensities of European signals and afternoon atmospherics on 23 kilocycles are shown with the corresponding yearly averages of sun spot numbers. A monthly average field intensity curve of Tuckerton WCI, 18.4 kilocycles, shows a return from the high values obtained in 1930 and 1931 to the average value of previous years. Some correlations between polarization of the reflected wave and sun spot numbers derived from a year of continuous recording of Tuckerton WCI, on loop antennas, are shown. The possibility of obtaining an independent value for the ground wave from such a series of observations is suggested.