EMPIRE BROADCASTS

Evening Post, Volume CXVI, Issue 23, 27 July 1933, Page 21

EMPIRE BROADCASTS

ENGINEERS' PROBLEMS

(From "The Post's" Representative.) SYDNEY, July 20.

The problems encountered by the British Broadcasting Corporation in their Empire transmission, as reported by a cable message recently, arg not fundamentally new, according to Australian physicists, although they are new in their application to Empire broadcasts. According to the cables the transmission, to Australia misses New Zealand, which easily picks up the signals designed. for-West Africa. Canada picks •up the 25-metro signal destined for Australia when she ought to be receiving the 19-metre broadcast.

Mr. G. H. Munro; physicist attached to the Radio Eesearch Board of Australia, said that, although these Empire transmissions were not strictly sent put on a beam, they were broadcast from directive aerials. The problems of the 8.8.C. engineers were apparently dv© to the fact that the signals strayed from the paths into which they were directed. The effect of using directional aerial was that signals were very much stronger in the path in which they were sent. Long-distance transmissions, however, depended on the ■ amount of day and night in the path of the signals, and this varied at different' times of the year. Because of those variations ifc was difficult to predict what wave lengths would be most suitable for reception in a distant land. ■ .

"For some reason," said Mr. Munro, "Paris .broadcast signals- are-stronger ia Australia, than those of .London, but If you look at the globe you will see that the path of London signals to Australia is much further north than that of Paris, and the ray goes nearer to the North Pole. The direct line from London to New Zealand is still more northerly. That probably explains why the programmes sent to Australia by the British Broadcasting Commission are not well received in New Zealand. They meet different conditions on the way. As I read the cable, both Canada and New Zealand .are receiving stray signals away, from the directional path. Canada receives the Australian signal sent across Europe, and not the other one which follows :i path across Canada. New Zealand geN: the West African signal, which is sent out in an almost i southerly direction, and should miss the Dominion. The answer to that seems to be that tho directional system is not fully efficient, and that conditions may happen to favour the stray, signals." , •

It is pointed out that the 8.8.C. 6ngineers are now working on. 49 "metres in the hope' that this wave length will suit both Australia and New Zealand. This channel has been very popular and effective in other parts of the world, notably the United States and Asiatic countries whoso broadcasts have- been well received in Australia.

Professor Branly, the .aged French savant, whose discovery of the coherer lies at the foundation of wireless science, has anything but a parental regard for the fruits of his invention. When some apparatus nianufaetursrs offered him a set of the very latest type, he politely but firmly declined. His friends reasoned with him, he gave way, and the set was brought to his home, but as soon as it ,was tuned jn, he grabbed his hat and stick and wdnt out.