FADING AND DISTORTION

Radio Record, Volume I, Issue 45, 25 May 1928, Page 15

FADING AND DISTORTION

ay A PECULIAR CAUSE Deflection of the wave from a bruad ast station due to the proximity of sereening mountains, such as Mount Egmont in relation to New Plymouth. may cause severe fading and distortion. The New York "Radio Broadeast" says: Ordinarily, the reception of two or three signals from the same station does not seriously affect the quality because one of the signal sources usually predominates over the others sufficiently to make their influence negligible. But there are many known cases where phase distortion aceounts for the poor quality with which high-grade stations are heard in some areas. When WE.A.F. broadcast from Walker Street, New York, several years ago, listeners in Pelham, New York, but 16 miles airline distance from the transmitter, complained that, even with the best of receivers, only a weak and distorted signal could be received. A thorough investigation with loop receivers and field strength measuring equipment revealed that two signals from WEAF, apparently eoming in from two different directions and, at some points, exactly 180 degrees out of phase, tended to cancel

each other. ‘Sinular efiects would he experienced when two stations radiate indentical programmes on the same channel.