This paper is a continuation of work reported in the Proceedings of the Institute of Radio Engineers for May 1928 by the same authors. A more extended study of echo signals with particular reference to directional characteristics and to diurnal variations has been carried out. Attention has also been given to the question of the relations between the echo signal and the frequency. Distortions, probably due to echo signals, have been recorded on long distance transmission. The relation between the echo signal and effective height of the Kennelly-Heaviside layer has been discussed.