Low-Frequency Radio Transmission

This paper presents the results of field intensity measurements on low-frequency transmission (17.8 kc) from the R.C.A. station WCI, located a, Tuckerton, N.J. The results of observations made at Newton Centre and at Medfordt Mass., are presented. Apparatus for alternating antenna observations with variously oriented loop observations is described and the results of such measurements are presented. The relation of the state of elliptical polarization of received signals to loop responses for various positions of the loop is investigated theoretically, and the results thus obtained are applied to an interpretation of the observations. The necessary approximations required to render this problem determinate are pointed out and their questionable validity emphasized. The mean of the received signal intensity in the absence of magnetic disturbances is lowest during the night, and strong sunrise and sunset peaks are found. An inversion of received signal intensity is noted during magnetic storm conditions. At such times the night field strength exceeds the day field.