PROBLEMS OF WIRELESS.

Wanganui Chronicle, Volume LXXVI, Issue 18444, 30 March 1922, Page 6

PROBLEMS OF WIRELESS.

SPECIAL RESEARCH WORK. EXPERIMENT AT SEA. Important researches into problems connected with the reception of wireless signals were carried out by a special staff from the Marconi WireJesis Telegraph Company’s re search laboratory during the voyage of the steamer Dorset which reached Auckland on Sunday morning from Liverpool. This research work is under the charge of Mr K. W. Tremelien, of the Marconi research laboratory, who explained that the apparatus used during these experiments was of an ultra-sensitive type, embodying all the latest improvements. The Marconi three electrode valve had been used throughout and on some occasions as many as 20 of these valves were in use at the same time.

By means of special arrangements it was possible for the ordinary continuous watch to be kept, in accordance with International Law. for distress, navigation warnings, and ordinary work at the. same time as the experimental work was in progress. For the purpose of the experiments the ship's permanent aerial was used, the ship’s equipment being specially adapted to wonk on an additional temporary aerial for the purpose of carrying on the ordinary routine work. Throughout the voyage reception was maintained day and night with European and American stations, from tne moment of leaving Liverpool until tied up alongside the Queen’s .’barf, Auckland. Cue of the first stations heard while testing in Liverpool was San Francisco, and this same statipn was oue of the last received before disconnecting upon arriving at Auckland. ELIMINATED OF ENCESExcellent signals were received from the Marconi High Power Station, at Carnarvon, Wales, throughout the voyage, and many other long distance stations were in touch. Bordeaux. France, was received at a distance of 11,880 miles. Berlin al 11,200 miles, these distances being the maximum possible with the ship’s course. Nearly every high-powered station in the world received with good strong signals, among which

were several stations around New York, Rome, Stavangar in Norway, Panama, San Francisco, Honolulu, Japan. Java, and tire Philippine Islands. ”

The problems of atmospherics, which received a good deal of attention, was touched upon by Mr Tremellen, who said that atmospheric discharges were the greatest difficulty which had to be contended with in connection with wireless work. The new Marconi directional reception gear, which was used during the voyage, was, he said, of the greatest assistance in dealing with this nuisance, as it was possible to concentrate in one particular direction, and any signals coming from another direction were totally eliminated. As the direction of these atmospherics might be different from that this apparatus was of great importance.

Interference from other stations working on or near the same wave length was given considerable attention. and another new Marconi instrument which responded to one note only was used. By means of this it was possible to render one or more interfering stations inaudible. VALUABLE TO NAVIGATION. Wireless is destined to play a very important part in the ocean navigation of the future, and the results obtained by Mr Tremellen aud his staff are of particular interest. A direction-finding installation by means of whch a ship may ascertain ier position at sea when atronomical observations arenot possible was used. This apparatus determines the exact direction from which a wireless wave is coming and by taking several readings from different stations in quick succession the bearing of the ship ’rom these fixed stations can be ascertained aud the position of the ship fixed. While in mid-Pacific a set of these bearings was obtained from Honolulu, ban Francisco, New York, Berlin and Panama, and when checked by Mr D. H. McMillan, the second officer, were found to be very accurate. Time signals which are used to check the ship’s chronometers were obtained from various stations throughout the voyage and an excellent rating maintaining. The ship’s operator spoke and worked the Chatham Island station at a distance of 2500 miles, and picked up the Wellington time signal at 3200 miles. Mr Tremellen was a-’*>isted in his work by Mr G. M. Allnut, of the laboratory staff, and Messrs J. Cunningham, W. C. Rowe and H. Dofett. Messrs Tremellen and Allnut will spend about a week in Auckland and will then proceed to Sydney, where they will continue their experiments l . They propose to complete their observations on tha return voyage to England.