||Technology in Australia 1788-1988
Table of Contents
I Part 1: Communications
i Before the Telegraph
ii Electrical Communication Before Federation
iii Federation to the End of the Second World War
iv Post-war and on to 1975
v 1975 ONWARDS
III Part 2: Early Australian Computers And Computing
Federation to the End of the Second World War (continued)An interesting Australian application of radio technology, combined with mechanical ingenuity, was developed by Traeger for the Australian Inland Mission to establish a communication system to alleviate the problems of isolation in the remoter areas of the continent. The service consisted of a base station, the first at Cloncurry in North-West Queensland, and a series of transceiver out-stations where the source of power for the equipment was from a mechanical pedal device, later replaced by batteries or by a home lighting plant. The service was extended to cover a wide section of inland Australia to give a basic communication service in areas beyond the reach of PPE lines.
that a special appropriation, sufficiently large to enable the present problems in radio to be thoroughly investigated should be made available to the Council for Scientific and Industrial Research.
This gave rise to the establishment of the Radio Research Board in the same year, with representation from the University of Sydney, the P.M.G. Department, the Defence Department, the University of Melbourne and CSIR. Early studies, under the aegis of the RRB, of the transmission of radio waves along the ground and in the upper atmosphere provided a sound basis for the initial planning of the Australian Broadcasting Service. Intensive studies of the fundamental mechanism in the ionosphere followed and the RRB developed an ongoing role in stimulating fundamental radio research within universities and encouragement of post-graduate research. Evans, in a well researched publication, has set out the detailed attainments, controversies and characteristics of those associated with the RRB over the period 1926 to 1945.
As has been noted earlier, the first task of the newly established PMG Research Laboratories related to the use of vacuum tube amplifiers on long trunk circuits to improve the quality of communications. A number of these amplifiers were installed and proved reasonably satisfactory and indeed, Adelaide and Perth still relied on a single VF amplified circuit in 1939. The major contribution which vacuum tubes were to make to trunk line technology in Australia with its great distances, lay, however, in the carrier technology which was then developing overseas, particularly by the AT&T Company in the USA. In 1925, the first 3 channel system in Australia, using equipment supplied by AT&T, was installed between Sydney and Melbourne and operated in the frequency band to 30 KHz providing 3 KHz channels. Further systems were soon installed on the Sydney-Brisbane, Sydney-Adelaide and Melbourne-Adelaide routes after upgrading of open wire pairs by re-transposing to single extra types.
As an indication of the rate of development, the Sydney-Maitland route was transposed in 1928, after investigation by AT&T engineers, to enable eight 3 channel systems to be installed. By 1936, after re-transposing had been carried out on an alternative route through Wisemans Ferry, the two routes carried a total of fourteen three channel systems, working to 30 kHz, a programme carrier system working 34 to 42.5 kHz and a telegraph carrier working to 10 kHz. In 1939, further growth was met by installation of separate go and return, 24 pairs in 12 quads, 40 Ib. conductor, special carrier type star quad cable in accordance with BPO specification 598. Table 4 (from reference by C. J. Griffiths who, with W. H. Walker, played an important role in the development of external plant engineering,) shows the twenty-year estimate of circuit development made in 1938, an estimate which events were to prove quite inadequate. In planning the cables, the Australian engineers developed specifications in the form of requirements to be met, rather than detailing a particular system or systems, establishing a practice which was to be the basis for seeking Australian communication equipment in the decades ahead.
Organisations in Australian Science at Work - Australia. Department of Defence; Australian Inland Mission; CSIRO; Radio Research Board; University of Melbourne. Department of Electrical Engineering
People in Bright Sparcs - Evans, W. F.; Griffiths, C. J.; Traeger, Alfred H.; Walker, W. H.
© 1988 Print Edition pages 553 - 554, Online Edition 2000
Published by Australian Science and Technology Heritage Centre, using the Web Academic Resource Publisher