Ultra-Short Radio Waves Cause A Surprise

Poverty Bay Herald, Volume LXII, Issue 18761, 18 July 1935, Page 11

Ultra-Short Radio Waves Cause A Surprise

CXPERIAIENTS have recently been been made which may have important effects on the future of television. The Kadio Research Board have received well authenticated reports of reception in London on the ultraahoit wave ,of 0 metres from Buenos Aires, a distance of 7000 miles. Reception from Rome and Oslo ,ori 7 metres has also been reported. Wave-lengths of this order.will be used for television. They are regarded as essentially short-range waves; in Jact. thp practical radius of the London high definition station is being estimated at 25 miles. This "limited range has been looked upon as a virtue, as it would mean freedom from interference. It hits also led to the assumption that a number of station* separated by distance might, use ihe same wave-length with

out jamming. Now the ultra-short waves have behaved as unexpectedly as the long waves did in the' early part of the century, £nd the short waves did within recent years. INFLUENCE OF SUN. Mr R. A. Watson Watt, Superintendent of the Radio Department of the National Physical Laboratory, the lending research expert in the country, said that the reception of ultrashort waves over long distances was dt. i to. rt flection of the indirect rays from the “E” region of the upper atmospheie. It occurred only when ' ho sun’s rays produced' an effect known f s ionisation, with particular in-

tensity. “At a certain period,” he said, “we were able to pick up the Slough Station ot the Radio Research Board telephony .between Rome and Sardinia o:i the wt.vcdength of 10 metres. From the conditions prevailing we were then r.lle to predict that we should again receive this tolephony between certsiin dates. The prediction proved correct. “According to present indications, however, it would be impossible to use these wave-lengths for regular long-distance communication, as reception at a fixed' time of day could not be guaranteed.” Sunspots, which have -a marked effect on short and ultra-short wave reception, vary in activity; according :o an IDyear cycle. The next years of maximum activity will be 1938-39, when short-wave reception conditions should be at their best. , Conditions are now on the upgrade, and further interesting light on the long-distance qualities .of. • the ultra-short w r avos may be expected. Since the last favorable poriod in 1927-2 S the technique of both trans-. mission and reeoption has improved greatly.