A study of the short-period sky-wave fading of cw emissions shows that observed characteristics of these fading distributions are functions of the relative amplitudes of the received

and

magneto-ionic components. When the received magneto-ionic components are essentially equal at the receiving point, severe and rapid fading occurs and variations in short-period fading are maximum. However, when a single mode of propagation is suppressed, the variations in short-period fading distributions of the received field are reduced and become lognormal in character. A new parameter is suggested to replace the Rayleigh distribution in cases where a more accurate formulation of short-period fading characteristics is desired. Finally, a description is given of a practical method of emitting cw radio transmissions, which yields reflections from the ionosphere of a single ionospheric mode, thereby obtaining some man-made control over short-period sky-wave fading.