1924 __ Voice transmission between Poldhu and Sydney
‣ Comment : In 1924 MARCONI built numerous short wave stations, in the 30-60 Mhz band, for british government, and on may 30 of that same year took place the first regular transmission of human voice between England (Poldhu) and Australia (Sydney). (Brunero, Angelo and Andrea Valori. 2001, “The invention of the radio”) — In February 1924, AWA [Amalgamated Wireless Australasia Ltd] engineers received a cable from Marconi, asking them to accept signals on the 90 metre wavelength from his Poldhu station in Cornwall. Two test sets were hastily constructed at AWA's Knox Street factory in Sydney, as there was no wireless set in Australia capable of receiving this wavelength. Just before dawn on 6 March 1924, the Poldhu signals were clearly heard by the monitoring team in the Sydney suburb of Willoughby. A whole series of tests began, with shorter and shorter wavelengths, and it was found that the 25 metre wavelength gave the best results. So successful were these trials that, by May 1924, Marconi implemented a series of short wave telephony trials to Australia. These also proved to be successful. In the latter part of 1924, Edward Victor Appleton, began a series of experiments which proved the existence of that layer in the upper atmosphere now called the ionosphere. Further experiments which led to the possibility of round the world broadcasting were carried out and in 1926 he discovered a further atmospheric layer 150 miles above ground, higher than the heaviside layer and electrically stronger. This layer, named the Appleton layer, reflects shortwaves round the earth. (Ian McLean, “Wireless Telegraphy in Australia”)
‣ Source : Ciolek, T. Matthew (2000), “Global Networking: a Timeline”, electronic publication, Research School of Pacific and Asian Studies, Australian National University, Canberra, 2000.
‣ Urls : http://www.cisi.unito.it/marconi/radeng.html (last visited ) http://www.angelfire.com/de/vk3kcm/Fiskville2.html (last visited )
No comment for this page