3LO'S SHORT-WAVE TESTS

Radio Record, Volume I, Issue 47, 8 June 1928, Page 13

3LO'S SHORT-WAVE TESTS

DAYLIGHT RANGE DIFFICULTY. Regarding the short-wave broadcast tests by 8L0, Melbourne, it is pointed out that normally, short-wave signals sent over comparatively short distances are subject to marked absorption, and, as a result, they are always much weaker close to a transmitting station, than is a signal transmitted on a longer wave-length. This fact, added to difficulties sometimes experienced in picking up short-wave signals, has prevented their extensive use for local broadcasting. It has been found, however, that the carrying properties of short wave-lengths differ very much from those of longer ones, and that in certain circumstances the daylight range of a shortwave signal greatly exceeds that of a long-wave one. Normally the daylight range of 3LO on 871 metres does not exceed about 200 miles, and in some eases it is a great denl less. Fixperiments have indicated that the daylight range of the 30-metre transmitter should be 1500 miles or 2000 miles. This would mean that where the long-wave transmitter could not serve all the Victorian listeners effectively in the daytime, the short-wave set could cover the whole of Australia, So far the daylight short-wave tests, by 3LO, Melbourne, have failed to give consistent satisfactory loudspeaker volume in Wellington at about 1700 miles distance. a