WIRELESS MARVEL

Dominion, Volume 26, Issue 10, 6 October 1932, Page 9

WIRELESS MARVEL

Marconi’s Latest Triumph ULTRA SHORTWAVES Information just received from London giving details of Marchese Marconi's experiments with ultra-short wave wireless, discloses that the success which attended his experiments in Italy (as reported in a cable message published in “The Dominion” on August 16 last) was achieved by means of an apparatus as small as a portable typewriter and a small battery su - cient to light a 50 candle-power electric lamp. Advices indicate that the experiments were more successful than was originally anticipated. Signor Marconi has been experimenting with shortwave broadcasting for years. Other experimenters have been working in the United States and France. Theoretically the experimenters concluded that it would not be possible for shortwave wireless to overcome the curvature of the earth, and that, therefore, the limit for effective transmission on short waves would be the horizon, the mileage distance being variously estimated at from 50 to 60 miles. This, theoretical limit had been exceeded by French experimenters, who, on three metres, established communication between Nice and Corsica, and by Americans on a wave-length of eight metres. In his early experiments with ultra-short waves Signor Marconi used a one-metre wave-length and then reduced that gradually until big final and most successful and eventful experiment was made with 57 centimetres. Converging the Beam.

The apparatus for converging the beam wireless to a pencil point is also so small as to be easily portable. The narrow beam —about 224 inches is focused by special mirrors. It has been found to be free from interference, fading and atmospherics. Actually the transmitted waves are aimed at the receiver. In the experiments, the result# of which have been made public, the transmitter was stationed on the height known as Rocca di Papa, 15 miles south-east of Rome, and the receiving apparatus on Signor Marconi’s yacht Elettra In the Mediterranean, about 60 miles distant. When communication was established the distance was gradually increased, and it was found that the waves were following. Communication was maintained with the transmitting station until the Elettra reached Cape Flgara, in Sardinia, a distance of 167 miles from the transmitter. The communication was maintained clearly and distinctly both telegraphically and telephonically. Commercial Importance. Radio experts in Britain and throughout Europe regard this latest discovery of Signor Marconi as one of great scientific importance and commercial promise. The experiments have shown that the half-metre wave preserves more of the pure wireless wave characteristics than was previously believed possible. Further, the tests have shown that the theory of the non-flexlbility of ultra-short wireless waves must be abandoned. It is now assumed that the ultra-short waves not only have flexibility, but also, in all probability, a curved trajectory. This is being tested in further experiments with a view to ascertalning the reasons for the 100-mile gap between theory and practice. It is now believed that there are possibilities of greatly extending the range of ultrashort wave wireless. It is not yet known whether the waves can be used for ordinary broadcasting. but the value of the system commercially and from governmental standpoints is recognised and admitted by all the leading radio experts who have investigated the results of the experiments. The great advantage is that the waves, being transmitted by directional beam, are secret and cannot be tapped. The small apparatus can easily be moved from place to place and easily concealed. Its use for private communications between the head offices and the various activities of industrial and commercial concerns is apparent. _____