WIRELESS TELEGRAPHY

Otago Daily Times, Issue 19260, 26 August 1924, Page 7

WIRELESS TELEGRAPHY

THE BEAM SYSTEM. LIMITATIONS IN DAYLIGHT. Press Association —By Telegraph—Copyright. LONDON, August 24. The Admiralty is unwilling to disclose its experts’ reports on the beam wireless system, but it is staled unofficially that they have proved it to be inoperative in daylight, and that it obviously would be relatively valueless compared with the super-power system, which would be opera live for the whole 24 hours. The Marconi Company informed the Australian Press Association that the beam was already operative throughout the hours of daylight, although: it had a restricted capacity. Nevertheless, the “day ranges have already proved reliable and not inconsiderable. ’’ The beam system was constantly improving, particularly when the sun was in low altitude. It was hopeful in the-near-future of giving a continuously efficient daytime service, even when the sun was in high altitudes.—A. and N.Z. Cable. In a recent lecture on the beam system before the Royal Society of Arts, in London, Mr Marconi said that nearly 30 years ago he had been able to demonstrate the “beam” system to the engineer-in-chief of the Post Office, using short naves, and pointed out how his attention had been diverted from this method by the easier method of the long wave. Tins he now regretted, for it was only recently that it had been discovered that the short waves alone could be focussed in definite directions like a searchlight, and wore capable of effects unobtainable by the long waves. Thus for many years there had been no research in this most important branch of the' science. Illustrating the reflectors for concentrating the wares, he showed a slide of the type now used. The reflectors consisted of a parabolic screen of short, vertical wires, and not of solid sheets of metal, as in the original experiments, and had been found to bo the most efficient. The series of experiments carried out between his yacht Elattra. and a small transmitting station at Poldhu last year, had shown that many theories held by experts were not correct, and the definite results had proved that the day range of signals was reliable, tho night ranges greater even than he had anticipated, and that intervening continents were no obstacle. It had also been discovered that tho altitude of the sun bore a relation to the strength of tho signals received, and that certain mathematical formal®, generally accepted as applying to wireless, did not operate in the case of tho short-wave method. In his experiments at a distance of 2330 miles from Poldhu, he had found the strength of tho received signals so great that none of the ordinary “atmospherics ever approached interference with signals from Poldhu. During these tests the radiation energy from Poldhu was 12-horse-power. The reflector concentrated this energy on tho yacht, and to get tho same result without a reflector, at that distance it would have been necessary to radiate over 160 horse-power. The tests made between Poldhu and Australia by day, using Morse signals, had been so surprisingly successful, though only a very ordinary improvised instrument was used for reception, that he was encouraged to try telephony by the fame means, and thus, on May 30, for the first time in history, and with only experimental arrangements, speech was transmitted by wireless from England to Sydney. Signor Marconi went on to explain how the efficiency of communication between distant parts of tho Empire could be increased, and also tho speed of the transmission of messages. “I am, ’ ne said, “of the opinion that by means of comparatively small stations a far greater number of words per 24 hours could be 1 transmitted between England, India, and her distant dominions than by means at the previously planned powerful and expensive stations.” ■ ' ss?