THE HISTORY OF SHORTWAVE RADIO IN AUSTRALIA

1920s - Receivers

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Project Overview
1800s - Land Telegraphy
1874 - Guglielmo Marconi - a Tribute
1895 - Wireless Telegraphy
1901 - Wireless Telegraphy
1902 - Wireless Telegraphy in Australia
1904 - Australian Coastal Radio
1906 - Wireless Telephony
1912 - Melbourne Radio - VIM
1914 - Shortwave Wireless Telephony
1920s - Commercial Shortwave Telephony Development
1920s - Receivers
1920 - The huge RCA Longwave Station in New York
1920 - Wireless broadcasting in Australia
1920s - First shortwave stations in Victoria
1921 - Discovery of Shortwave Propagation
1921 - Koo Wee Rup (Victoria) Experimental Wireless Receiving Station
1923- Longwave Broadcasting in Australia
1923 - Evolution of Australian Domestic Radio
1924 - 3LO - Melbourne's Second Broadcaster
1924 - 3AR - Melbourne's first broadcaster
1924 - The Braybrook (Melbourne) Transmitting Site
1925 - First Shortwave Stations in Western Australia
1926 - First Shortwave Stations in New South Wales
1926 - RAAF Communications - Laverton (Vic)
1927 - Beam Wireless Worldwide
1927 - Beam Wireless from Australia
1928 - ABC Lyndhurst (Victoria)
1930 - AWA Receiving Station at La Perouse (Sydney)
1930 - AWA Radio Centre at Pennant Hills
1933 (to 1969) - Shortwave Radio Clubs in Australia
1936 - Ship Broadcaster - the MS Kanimbla
1939 - Belconnen Communications Station (Canberra)
1940 - RAAF Receiving Station at Werribee (Victoria)
1941 - RAAF Frognall (Melbourne)
1941 - ABC Brisbane
1942 - Army Wireless Chain - west of Melbourne
1942 - Dutch Stations in Australia
1943 - ABC Radio Australia - Shepparton (Victoria)
1943 - Army Shortwave HF Stations in Melbourne
1944 - ABC - Radio Australia - Looking Back
1945 - PMG Receiving Station - Highpark (Victoria)
1945 - Radio Australia - DXers Calling
1946 - Radio Australia - Communications Programs
1946 - VNG Time Signal Station
1948 - Radio Australia QSL Cards
1948 - ABC Sydney
1966 - ABC Cox Peninsula (Darwin)
1970 (to 2012) - Shortwave Radio Clubs in Australia
1975 - ABC Gnangara (Western Australia)
1975 - ABC Carnarvon (Western Australia)
1978 - Omega Navigation Station - Woodside (Victoria)
1985 - ABC Northern Territory
1989 - ABC Brandon (Queensland)
2003 - Private Shortwave Broadcasters
Timeline - Part One - 1839 to 1927
Timeline - Part Two - 1928 to 2012
SPECIAL - Licencing of Shortwave Broadcasters
SPECIAL - Radio Receivers for Shortwave
SPECIAL - Radio Monitoring as a Hobby
Epilogue
Bibliography, References and Resources
Links to the author's personal websites

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AWA receivers 1920s

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AWA receiver 1933

1920s - RECEIVER DEVELOPMENT
Receivers in the mid 20’s were of course battery operated, with an A, B, and C battery.  The tuning range varied, and covered what would later become the mediumwave and shortwave bands. The superhet had not as yet been invented and neither had the tetrode or pentode valves.

Directly heated valves were used, generally in two stage sets – one regenerative detector followed by an audio output stage. More pretentious sets accommodated several RF amplifier stages, followed by a detector and one or more audio amplifier stages The ganged variable capacitor had not yet been invented, and single gang tuning capacitors were all brought out to separate front panel controls, each requiring to be lined up manually. Receivers were invariably regenerative types – howls and squeals were the order things due to their inherent radiation capabilities.

Some receivers were very elaborate indeed, with luxurious panelled cabinets, One model “ advertised as a "Udisco -6” covered all frequencies from 750 kHz up to 15 MHz Receivers of those days were regarded as part of the furniture

Prices quoted for this particular model were around 100, complete with stand, speaker, batteries, valves, and antenna. That sort of price was a lot of money in those days!

Radio magazines proliferated, and emphasised the home construction craze of the 1920's. Technical editors published constructional details of receivers, which was followed by the release of kits of parts by commercial dealers. There were innumerable radio displays and exhibitions.

Band changing was generally by plug in coils - some advanced sets featured mechanical shortwave switching features.

Battery operated sets continued until about l928, when the first of the battery eliminators appeared, due to the introduction of grid electricity. The first “all-electric" set appeared towards the end of the 1920's, and with it the first of the indirectly heated valves - cumbersome batteries started to phase down, but they would continue to be used for many years by hobbyists who could  not afford the latest all-electric radios.

During the 1930s, technological advances saw the invention of the tetrode and pentode valves, and the introduction of the superheterodyne receiver concept. By the start of WW2, most households had at least one superhet radio, occupying pride of place in the main room of the home.

Antenna systems in the l920s were generally consisted of long wires. The longer and higher the wire, the greater the signal pickup. Elaborate insulation properties were introduced for feeding the antenna to the receiver. Emphasis was also placed on good earthing systems, which were a carryover from the crystal set days, it was not until the advent of the superhet that the large antenna systems started to decline, due to the increased

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1933 - Radio Exhibition in Sydney

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1933 - Radio Exhibition in Sydney

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1928 - Silvatone advert (Melbourne)

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