MARCONI’S NEW MARVEL

Evening Star, Issue 19456, 14 January 1927, Page 7

MARCONI’S NEW MARVEL

WIRELESS BEAM SYSTEM TRANSMISSION AT SPEED OF FLASH The Marconi Company recently received from the Engineer-in-chief of the Post Office tho official certificate that the wireless stations constructed j at Bodmin and Bridgewater for communication with Canada on the Mar- j coni short-wave beam principle have j passed their' official seven days’ test. j _ A high-speed wireless telegraph ser-; vice between Great Britain and Canada through these stations is now opera- | ting. With the first dominion Beam , service thus established, Great Brtiain’a world leadership in wireless communi- ■ cation "is maintained. . I As the home of Senator Marconi’s j first long distance wireless experiments Great Britain was the pioneer country in commercial wireless telegraphy. Now, with the modern high-power valve transmitting station at Rugby for allround communication, and tho Marconi beam stations for direct communication between the Mother Country and 1 each of the dominions, it possesses the ■ most complete, up-to-date, and efficient j wireless service of any country in the world. it was in 1923, after several years of discussion, that the Government definitely decided to proceed with the erection of wireless stations to communicate with each of the dominions. The dominions had been pressing for such a service for some years, and when the British Government’s decision was taken they immediately put arrangements in hand for tho erection of corresponding stations to form a complete Empire wireless service. While negotiations were proceeding with the Marconi Company for tho erection of high-power, long-walve valve transmitting stations to carry out those sendees, Senator Marconi became convinced, as the result of his experiments, that a new system of wireless telegraphy could be developed that would enable these Imperial services to be carried out much more efficiently and at much lower cost than was contemplated by the high-power long-wave wireless stations.

His plan was to use short wireless waves—of 100 metres or less—which, contrary to the _ generally accepted theory at that time, he had proved to bo' reliable for communicating over great distances; also to increase the strength of signals and the speed and efficiency of working by employing reflectors to concentrate into a narrow beam the wireless energy at the transmitting sation, and to reflect a greater amount of energy on to the receiving aerial at the receiving station. _ As Senator Marconi has said, a considerable 'amount of courage was necessary to propose such a revolutionary change. He had no uncertainty, however, neither had the company of which he is' the chairman; and the proposal was put before the Government. So convincing were the arguments in favor of the new system that the whole technical policy of Imperial wireless communication was revised and the Government entered_ into a contract with Marconi’s Wireless Telegraph Company, Ltd., to build short-wave beam wireless stations in England_ to communicate with Canada, South Africa, Australia and India. The Government and wireless companies in each of these dominions were equally impressed with the value of the beam system, and contracted with" the Marconi Company to Wild corresponding stations to communicate with those being erected in England. The building of the stations was started in April, 1925. They have been longer under construction than was at first anticipated, but this has been due to the fact that research work has been earned on simultaneously with constructional work, and many valuable improvements on the original designs have been made as the work progressed. Power valves have bad specially to be designed to deal with the extra high frequencies of short-wave working, and the Marconi oil-cooled valves at the transmitting station are claimed to be the most efficient of their kind in the world.

The institution of direct Marconi wireless telegraph services between Loudon and Pans and other Continental centres lias shown that ncw 4 telegraph traffic is created hy the provision of new and ranid means of communication. It can therefore be anticipated that the establishment of the beam services, which can be worked at a speed which will enable large volumes of traffic to be dealt with in the shortest possible time, will create new business that has not previously been possible, and so bestow a great benefit on the commerce of Great Bntain and Canada. Tho beam Iran ■•mitring station m Canada is situated at Diummenciville, thirty miles east of .Montreal, and the receiving station at Yamacbieho, twenty-five miles north of Drummondvillo. These stations arc linked up by land line to the central office of the Canadian Marconi Company in Montreal, in the same way that the English stations are linked to the General PostOffice. Beam stations are also being erected in Canada, for direct communication with Australia, and corresponding beam stations are being built at Melbourne.

The sites occupied by the beam stations at Bodmin and Bridgewater for communication with Ccr.wT* arc also utilised tor the .stations to be used for communication with South Africa. These South African stations are practically complete.. Similar stations are being built at Tctney, near Grimsby, and'at Winthorpe, near Skegness, for communication with Australia and India—tl}e Grimsby stations being transmitting stations, and the Skegness stations receiving stations. Corresponding stations are being built in the dominions near Cape Town, Melbourne, and Bombay. All these stations arc in an advanced state of construction, and are expected to bo opened within the next few months. This will complete the present Imperial scheme, but outside this scheme the Marconi Company is already engaged on a considerable development of commercial telegraph services on the beam principle. The company holds a license from the Post Office to conduct wireless telegraph services with certain Continental countries and with all other foreign countries outside Europe. In addition to the wireless stations, it has been operating on the.se services for some years, it has a beam station nearly completed at Dorchester ior communication with North and South America. A corresponding station is also in process of erection at Rio dc Janeiro.

It is claimed that a beam wireless station has the following distinct advantages over any other form of telegraph communications for point to point communication, over similar distances:—The capital expenditure involved is considerably less, it is more economical to run and maintain, and it is by far the most speedy method of communication yet devised. The speed of working the beam system is at present limited only by the mechanical limitations of the transmitting and recording instruments, and when suitable means of recording over landlines at higher speeds than at present obtainable have been developed) it will be possible to increase correspondingly the over-all speed of signalling. The results of tests between England and Canada have shown that the use of beam aerials at both transmitting and receiving stations has resulted in a strength of signal some 100 times that obtainable with non-directional transmitting and receiving aerials at each end, and utilising the same power, and it has enabled the service to be carried oip under conditions when signals obtained by utilising non-directional aerials were hardly appreciable. At the same time, the use of beam aerials has resulted in a very large degree of freedom from atmospheric disturbance.