Radio Broadcast (Nov 1926-Apr 1927)

NOVEMBER, 1926 LOOKING BACK OVER THIRTY YEARS 29 Marconi's have been of the earth would inexorably hinder communications over distances greater than a few tens of kilometres, but I did not believe this and I was soon able to prove by my experiments conducted between the Lizard and the Isle of Wight off the coast of England, across a distance of 300 kilometres, in which the curvature of the earth intervenes rather considerably, that it did not offer any obstacle to radio telegraphic transmission. LONG DISTANCE "WIRELESS" A DREAM? TT WAS then affirmed that * transmissions over still greater distances were the dream of a visionary but after the experiments which I carried out in December, 1901, between England and Newfoundland in North America, during which I succeeded in communicating for the first time across the Atlantic Ocean, everyone began to be convinced that very probably there would no longer be any distance in the world which could obstruct the propagation of electric waves. The happy result obtained by those first experiments of mine between Europe and America encouraged me in the prosecution of my studies to face the solution of a difficult problem — commercial radio telegraph communication between Europe and America, and with so many other distant countries where the practical object to be reached would justify the risk of the expenditure of a huge capital for the execution of experiments which, in Italy, were qualified as of rather doubtful success. In my experiments conducted on the Atlantic during the winter of 1902 I found myself impeded by an unforeseen difficulty caused by the effect of solar light on radio telegraphic transmissions, a phenomenon which I discovered during a voyage made on board the ship Philadelphia; on account of the effect of the light, at a distance of more than 700 miles all reception became impossible when the sun rose. But with the increase of the wavelength I found that this difficulty also could be overcome. Then all students of radio telegraphy devoted themselves to the use of longer and longer waves and thus from those of 1000 and 2000 meters there was a gradual transition to the use of waves which reached the length of over 30 kilometres. Other difficulties presented themselves as a result of interference between neighboring stations, a difficulty which, it seemed, would cause a very great limitation in the practical applications of radio telegraphy. But with new tuned circuits, which I patented in 1898 and 1900 and experimented with on the south coast of England, such difficulties also disappeared for the greater part. It was then proved for the first time that many neighboring stations among those tuned on different waves could communicate simultaneously without interfering with each other. Following my first long-distance experiments over the sea, it was affirmed that communications across mountainous continents would be impossible. But with the wireless telegraph experiments on the Royal Vessel Carlo Alberto, which, by the will of H. M. the King of Italy, was placed THE ELETTRA private radio yacht. Very many of the Senatore's carried out from the middle of the ocean aboard pointed Elettra at my disposal, I was able to demonstrate that the Alps and Pyrenees were easily surmounted by the electric waves I was using. But there always remained inexplicable periods of interruption; there also always remained great difficulties occasioned by the low sensitiveness of the receivers then used; there also always remained the enormous obstacles produced by atmospheric electric discharges. It was then said that at that point the development of radio telegraphy wa finished; that its employment might be useful at sea for the safety of human life during navigation, but that its employment would be rather limited and rather difficult between distant continents. It was stated that radio telegraphy would never be in a position to compete with other rapid means of communication over long distances, such as that carried on by cables. But even in the face of such observations often made officially in the parliaments of great nations, I was never discouraged. We Bolognese often smile in the face of the most difficult situations. PROGRESS AIDS PROGRESS TN FACT, by means of the use 1 of thermionic valves — a brilliant conception of Fleming, perfected by DeForest, Langmuir, and Armstrong in America, by Meissner in Germany, and by experiments Round and Franklin in England the well ap — and by means of the use of balanced tuned circuits, of electric filters, of power amplifiers and finally of directional radiators, I succeeded in obtaining results such as to ensure a regular radio telegraphic service by day and night between Europe and America; thus also, in 1918, I could for the first time in history communicate from England to Australia, i. e., almost as far as the antipodes, over a distance of about 20,000 kilometres (12,500 miles). But to obtain such results, huge and very costly installations were required, based on the use of many hundreds of kilo ~r.„„ . — 1901.^(izth Hopth, 3rD9£^L December. ^ AN HISTORICAL DOCUMENT Pages from the diary of Mr. S. S. Kemp, Marconi's assistant at Signal Hill, Newfoundland, just about twenty-five years ago (December 12th, 1901), when wireless signals were first transmitted across the Atlantic from Poldhu, England, and received at the Newfoundland station. This was the occasion of the transmission of the famous letter "S"