Note on High-Frequency Transmission during the Summer of 1930

The results of observations of echo signals at Cheltenham, Md., on 20 and 25 megacycles during the summer of 1930 are presented. A notable absence of strong echoes during this period is noted and marked abnormalities in their time of occurrence (as compared with previously reported results) are found. A comparison with field strength observations on GBU, (18.62 mc) is included and a discussion of possible causes of the abnormalities is given. The close correlation between the intensity of echoes and the intensity of the reception at Bellevue of the high-frequency signals from Rocky Point is also emphasized.