Further Studies of the Kennelly-Heaviside Layer by the Echo-Method

Recent observations of the Kennelly-Heaviside layer by the echo-method are described. Multivibrator-modulation was used, giving extremely sharp "peaks" on 4,435 and 8,870 kc. Practically all of the observations were made on the former frequency, as 8,870 kc skipped over the receiver, which was very near the transmitter. Two 24-hour series of observations showed a marked diurnal-variation in the effective height of the layer and in the echo-pattern received for each transmitted "peak." The echo-pattern shows multiplicities during the day and evening, but becomes very complex at night. A few observations made during the magnetic disturbance of October 17-19, 1928, showed an unusually great effective height and a change in the echo-pattern. Daytime heights for a number of days during the autumn of 1928 are given.