Wireless Telegraphy in Australia
In Australia - a newly federated country - wireless telegraphy quickly came under the control of the new Federal Government through the Wireless Telegraphy Act of 1905.
In 1906 the Marconi Company, in an attempt to obtain authority to develop wireless telegraphy services in Australia, installed transmitting and receiving equipment at Queenscliff, Victoria and at Devonport, Tasmania and conducted successful communications across Bass Strait, but the Government did not purchase the equipment or approve the service.
In this same year Australia’s first two-way wireless telegraphy station was built at Queenscliff in Victoria, Marconi was almost monopolizing the industry worldwide with companies in Europe, the USA (later to be renamed the Radio Corporation of America - RCA - in 1919) and Australia. Since then broadcasting has remained the responsibility of federal governments.
Since 1906, the Marconi Company had been making proposals to link Britain with the countries of the British Empire by radio. Initially, the proposal was for an 'Imperial Wireless Chain' of repeater stations no more than 1600 km apart, but by 1911, it had been decided to use very high powered long-wave stations situated in England and the other countries to communicate directly. E.T. Fisk of Amalgamated Wireless (Australasia) Ltd. went to England in 1916 to discuss the proposals to link Australia with Britain in this way, and contracts were let with the Marconi Company.
The Beam Wireless Service
The establishment of Australia's first coastal radio station in Sydney, by the fledgling Australasian Wireless Company in 1910, signalled a new era of communication. Further developments followed when the company built two high-powered stations at Pennant Hills, Sydney, and Applecross, near Perth.
In 1913, Amalgamated Wireless Australasia Ltd (AWA) was formed, assuming the responsibilities of the Australasian Wireless Company. AWA's Managing Director, Ernest Fisk, outstanding figure in radio development in Australia, believed in the new science of radio and was convinced that one day, direct wireless communication would be possible between Australia and Great Britain.
In 1916, Fisk went to England for discussions with the Marconi Company. From these talks it was agreed that radio trials between England and Australia would proceed.
The First World War of 1914-18 showed the Vulnerability of the existing system of submarine cables for Australia’s communications needs. It was feared contact between the UK and Australia could be lost. The first important step towards direct communication was taken in 1918 when Sir Ernest Fisk received the first long-wave signals and succeeded in receiving messages direct from England at his home in Wahroonga, Sydney. This was the culmination of many experiments carried out in co-operation with Guglielmo Marconi, and with the approval of the Admiralty, which gave permission for the Marconi station at Carnarvon to be released from its special war transmissions for the purpose.
Although certain European stations had been occasionally intercepted in Australia, it was not until 22nd September, 1918, that wireless messages transmitted from England were addressed to, and correctly received without relay in Australia.
These messages were from the Rt. Hon. W. M. Hughes, then Prime Minister of Australia, and the Rt. Hon. Sir Joseph Cook, then Minister for the Navy, and were sent by the Marconi Station at Carnarvon and transcribed by Sir Ernest Fisk at his experimental station at his home, at the corner of Cleveland and Stuart streets, Wahroonga in New South Wales.
In honour of the historic event, Ku-ring-gai Council, the historical society of NSW and the Amalgamated Wireless Australasia, in 1935, jointly funded the building of a monument which now stands on the corner of Stuart and Cleveland streets. Although the greatest interest was in the technical achievement, the texts of the messages have historic value to Australians, and are quoted:
From the Rt. Hon. W. M. Hughes,
" I have just returned from a visit to the battlefields where the glorious valour and dash of the Australian troops saved Amiens and forced back the legions of the enemy, filled with greater admiration than ever for these glorious men and more convinced than ever that it is the duty of their fellow citizens to keep these magnificent battalions up to their full strength."
From the Rt. Hon. Sir Joseph Cook,
" Royal Australian Navy is magnificently bearing its part in the great struggle. Spirit of sailors alike is beyond praise. Recent hard fighting brilliantly successful, but makes reinforcements imperative. Australia hardly realises the wonderful reputation which our men have won. Every effort being constantly made here to dispose of Australia's surplus products."
The signals were radiated on a wavelength of 14,300 metres, and traversed approximately 9,300 miles to the receiver. This comprised one stage of radio frequency amplification, a detector and five audio stages. The Marconi Company conducted experiments in 1920 and 1921 into the strength of longwave radio signals received at distant places; included was Koo-Wee-Rup. (See “Radio Waves”, April 2001, Experiment at Koo-Wee-Rup)
Experiments were continued and eventually an experimental station was established at Koo-wee-rup near Melbourne. A directional aerial having a heartshaped polar diagram was employed, and the old receiver was replaced by a new one of the heterodyne type, comprising six stages of radio frequency amplification and two stages of audio frequency amplification.
For over a year, the signal strengths of many stations were carefully measured and the results showed that wireless signals could be received over long periods each day from New York, Rome, England, Paris and Germany, and were sufficiently consistent to assure regular wireless communication between England and Australia.
Tests between Koo-Wee-Rup and England proved that direct radio links were possible across the globe.
Immediately after these trials, in 1920, AWA and the Marconi Company submitted a proposal to the Australian Government to establish a direct long-wave radio service between Australia and Britain. This proposal was held in abeyance when the British Government established a committee to investigate the feasibility of establishing an Imperial wireless chain. The recommendations from this Committee displeased the Australian Government, which feared being left isolated and vulnerable at the end of the chain.
The preliminary technical problems having been solved, it was now possible to apply the experience gained to the establishment for a commercial service. Long delays, however, resulted from the hesitancy of the British Government to co-operate in any scheme of direct communication. The British attitude had been formulated on the report of an expert committee, which had recommended a system of relay stations at intervals of 2000 miles, with a station at Darwin as the extreme terminal.
Such an arrangement that Australia suffered all the disadvantages of cumulative delay, and it is highly doubtful if such a service could have been commercially successful, and, indeed, a considerable deficit was predicted by the expert committee.
On the advocacy of the Rt. Hon. W. M. Hughes, advised by Sir Ernest Fisk, Empire communications were again reviewed, and at the Imperial Conference in 1921, Britain agreed to cooperate in Australia's proposals for direct services. South Africa and the other Dominions followed Australia's lead, and supported its proposals. Delegates to the 1921 Imperial Wireless Conference of the wireless chain proposal accepted this proposal in 1922, following the rejection.
Following the abandonment by the Empire of the relay scheme, the Federal Government appointed a representative Select Committee, comprising members of both sides of the House, to study the best means of implementing the communication decisions reached in the Imperial discussions.
After a complete investigation of the available systems and proposals, the Committee recommended that the Government enter into an agreement with Amalgamated Wireless. In accepting the AWA proposal, the Government acquired 50 per cent of the company's shareholding, plus one share. The agreement provided that the Commonwealth Government was to hold 500,001 £1 shares out of a capital of £1,000,000. The Government was to appoint three directors to a board of seven, the private shareholders three directors, and that the seventh director be selected by a majority vote of the other six.
The Company was to construct and maintain in Australia, stations capable of direct commercial services to Canada and to the United Kingdom, to provide for a suitable corresponding station in the United Kingdom and to take over the coastal radio stations, which were operated at a considerable loss.
Certain guarantees regarding communication were also required, and the company was also to proceed with the development, manufacture, sale and use of radio apparatus.
This agreement gave AWA the sole right to construct wireless stations in Australia.
However, a previous agreement struck between AWA and the Marconi Company in 1913 meant that the Marconi Company would be the sole contractor to the necessary radio stations in Australia; AWA would act as the operating company.
During World War I, radio pioneer Guglielmo Marconi had begun experiments into shortwave radio. Later, whilst negotiations and testing proceeded for building a high powered long wave wireless station in Australia, Marconi continued his research into shortwave transmissions.
Marconis’ experiments between his station at Poldhu in Cornwall, utilising a new Franklin Beam Antenna array, and his yacht Elettra sailing in the Atlantic, showed that “short-waves were less affected by sunlight than long-waves, which travel by the path of maximum darkness, and that the propagation of short waves was unaffected by intervening land masses”. The existence of the ionosphere had not yet been realized.
In February 1924, AWA 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.
In so far as overseas communications were concerned, the agreement for the direct service was subsequently modified in two main points. Owing to a change in its policy, the British Government decided to erect a suitable station in England, and so the company, AWA Ltd, was freed from its obligation in that respect. The second modification was of considerable technical importance. Immediately prior to the commencement of work on the stations, Marconi announced the development of what was termed the " beam system."
Charles Samuel Franklin
This system, developed by Charles Samuel Franklin, one of Marconi’s closest associates, employed the then little used short waves, and incorporated a system of reflectors behind the aerials, giving directive propagation with a resultant gain in signal strength at the receiver. The new system had the important advantages of a much greater freedom from atmospherics and of requiring very much less power. Although much of the preliminary work for the erection of the long wave stations had been done, it was decided, with the approval of the Commonwealth Government, to test the beam system.
The plans were modified accordingly, and this decision more than halved the capital expenditure required for the erection of the Australian stations.
The first Imperial wireless beam service was opened in October, 1926, between Great Britain and Canada. It marked the culminating point of 10 years of HF experimental work and was a turning point in wireless history in that it marked the end of the development of high power LF transmitting stations, of which Rugby may be said to be an example.
Beam Wireless comes to Australia.
Following his successful trials with shortwave radio, Marconi proposed to Commonwealth governments that he provide an Empire wireless service using direct shortwave links. He promised that such a service would operate at 1/50th of the power, three times the speed, and 1/20th the cost of any system currently in operation or under construction.
The Governments of South Africa, Canada and Australia immediately approved the scheme, and the Australian Government signed a new contract with AWA in which the company would manage the construction and operation of “a station in Australia which would effect direct wireless communication with Britain and Canada”.
AWA accepted a tender from the Marconi Company to erect two receiving stations and two transmitting stations in Australia; both would communicate with Britain and Canada. The cost, £119,000, was substantially less than the £500,000 that would have been required to build a long-wave radio station.
Under the terms of this agreement, the Marconi Company was to demonstrate that the completed stations could send and receive messages accurately at the rate of 100 five letter words per minute over a period of seven hours per day (a duplex capacity of 21,600 words per day). The Marconi Company guaranteed that the new stations would be able to handle double this amount.
In order to select suitable sites for these stations, transmission and reception tests were made at several locations to determine local atmospheric and other conditions.
Considerable investigation was made in order to determine the wavelengths most suitable for giving reliable communication' over the longest daily period, and tests demonstrated that a wavelength in the vicinity of 25 metres would be the most desirable.
A 154 hectare site for the transmitting station was chosen at Ballan and a site for the receiving stations was found at Rockbank. Both sites were close to Melbourne to allow easy management.
The stations communicating with England were capable of transmitting and receiving messages from both directions around the globe, which meant that almost continuous communication could be carried out both day and night.
It was planned that both the receiving and transmitting stations would be controlled from AWA's central office in Melbourne by landline. Messages would be relayed to other capital cities via landline or via feeder stations such as that at Pennant Hills, which was connected to the Sydney Office by landline.
The Australia-Britain Beam Wireless Service to England was opened on 8th of April, 1927, and the service to Canada some 15 months later. The transmitting beam station was erected at Ballan, some sixty miles from Melbourne, and a site twenty miles from Melbourne, at Rockbank, was selected for the receivers, the stations being connected by landline to a central office in Melbourne, where the actual transmission and reception is effected. Ballan station was engined by three 150 h.p. Diesels, and both stations were complete with staff buildings consisting of bachelor quarters, cottages, and recreation rooms.
A school for the education of the children was erected in the transmitter grounds at what was to become Fiskville.
On September 5th, 1927, Ernest Fisk transmitted the first Empire radio broadcast from Sydney to London. On October 31st the following year, he conducted public demonstrations of two-way telephone links with America. Within two years, Australia and Great Britain were linked by a public radio-telephone service and in 1934, the phototelegraph service was introduced on the AustraliaGreat Britain beam circuit.
During the 1940s’- a turbulent period which included the Second World War – several conferences were held in England to discuss “Empire” communications. A 1945 conference recommended public ownership of all such services and at the end of that year these recommendations were accepted by the Australian Government, leading to an act, in 1946, to establish the Overseas Telecommunications Commission.
This was a fundamental change in Australia’s communication services, from private enterprise to government authority, and was a major change for AWA and its engineers and the support staff involved in the Beam Service. AWA carried out some hard bargaining for those staff transferred to the new Commission, to make sure they were not affected unfavourably in matters such as pensions, superannuation, long service leave and other rights.
Under a “Care and management” agreement between AWA and OTC, the company continued to operate the service until January 31st, 1947, and OTC commenced its operation on February 1st that year. The final transfer was carried out smoothly. In a letter to AWA’s Managing Director, Lionel Hooke, the chairman of OTC Mr J Malone, expressed the gratitude of the Commission for the companys splendid co-operation and his confidence in continuing good relations in the future.
The Beam Wireless Stations: Ballan (Fiskville)
Staff quarters were completed at the Ballan site in 1927, and comprised eleven cottages for married staff and a substantial building to be used for bachelors' quarters. All cottages were supplied with electricity and hot and cold running water. Although, initially, conditions were not ideal, with flooding rains and snow, followed by drought, the community flourished. The roads were soon improved, most families owned a car, and telephones and radiola 'supers' lessened the isolation.
AWA built a recreation hall and purchased a pianola for its employees. In their leisure time, staff and their families played tennis or golf; some took up hunting. The Ballan Social Committee organised regular picnics, which were sometimes attended by Beam staff from Melbourne or Rockbank.
In 1933, the name of the Ballan site was changed to Fiskville, in honour of its founding father Sir Ernest Fisk, and the small community opened its own school, built to take 32 pupils. Fiskville now had an identity of it’s own.
The transmitting station itself included a powerhouse, which was equipped with three large crude oil engines, each having three cylinders, which drove an electric generator. The power from these generators was taken to a switchboard, which operated other machines.
The transmitter produced RF at a frequency of 11.6 MHz, which was fed to the aerials. The plate circuits of the transmitter required 10,000 volts to operate them, produced by stepping up the voltage through a transformer to a rectifier bank consisting of sixteen valves, each about the size of a football, mounted on slabs of glass on a rack.
The Rockbank Receiving station.
The receiving station building at Rockbank, 24 kilometres north-west of Melbourne, was much smaller than the transmitting building at Ballan, mostly due to the fact that the enormous power needed to run the transmitters at Ballan was not required.
One staff member wrote: 'Here there is no bluster of shrilling machines as at Ballan, no noisy powerhouse, no atmosphere of unleashed, untold energy. Here is a purposeful silence, a sense of listening; even the building crouching at the feet of the mighty aerial masts seems to be huddling there with its finger on its lips. For Rockbank is gathering in the power generated in another hemisphere; gathering in, on its sensitive antennae, intangible rays which, focused on Australia, are emitted from an upended framework of inanimate wires on the other side of the world!'.
Lead in systems from the aerials terminated in a special room housing the receivers which, by 1934, included one each for British traffic, Canadian traffic, the Picturegram Service and a spare.
The signals were picked up, amplified, and passed by landline to the Melbourne or Sydney offices. As the Beam Service expanded, so did the receiving facilities at Rockbank. Between 1935 and 1947, several new arrays of aerials were erected for work with Montreal, Port Moresby, San Francisco and the new relay stations at Perth, Colombo, and Bombay.
Staff housing was completed in 1926, with four cottages for married staff and a large single mens' quarters, all equipped with electricity and running water. In 1935, six additional above ground water tanks were supplied and a petrol pump was installed at the station for staff cars. By the 1950s, Rockbank had become part of Melbourne's suburbia, with land being subdivided and much house building taking place in the area.
As new technology was introduced, Rockbank's role in overseas telecommunications services diminished.
The station finally closed its doors in May 1969.
Looking down the line of the antenna
The system consists of a unidirectional broadside array composed of a line of directly excited Franklin " uniform " aerials, spaced usually a half wave length apart, with another parallel line of reflector aerials situated a quarter wavelength behind, having aerials spaced a quarter wavelength apart. The directly excited " in-phase " aerials are energised in pairs from a branched concentric feeder system, shown diagrammatically in Fig. 1 (a) and (b).
The rows of aerials are several wavelengths in height, and alternate half wavelength suppression is carried out in an improved manner, the older phasing coils having been replaced by a " folded back " aerial. This is shown diagrammatically in Fig. 1 (c), and represents an approach to the ideal uniform current aerial.
Reflector aerials are usually built up of insulated half wavelength sections.
The system produces a beam inclined upwards at an angle of about 15` to the horizontal, having a divergence of about 11’ depending upon the aperture of the array.(Fig 2)
The use of a multiple feeder system makes it easy to mis-phase the currents supplied to the aerials in line. It is sometimes done by altering the equality of the length of the subsidiary feeder lines. In the Franklin system, correct impedance matching and control of the current phase is simultaneously done by arranging a simple parallel circuit, Fig. 1 (a),at each bifurcation of the feeder. Reference has already been made to the use of this mis-phasing in order to swing the beam through some small angle in case of need.
With a given aerial system, it is possible to cover a frequency band some 15 per cent. in width without serious loss of efficiency. This is due to the high radiation resistance of the array, which, in turn, is partly due to the use of twice as many reflector aerials as energised ones.
Experiments had shown that signals travelled to Australia along one or other of the two great circle paths joining the transmitter and the receiver, the path taken being largely determined by the distribution of daylight and darkness over the two routes. The aerials were therefore made capable of projecting the radiation in both a north-westerly and south-easterly direction.
The original Beam stations at Rockbank and Ballan had some similarities, one of the most distinctive being the masts. Each station had three masts (known as Franklin masts) placed 195 metres apart, standing 75 metres high, made from lattice steel and weighing 50 tons. Each mast supported a crossarm 27 metres in length and was stayed by four wires placed at right angles which were buried in concrete blocks about 33 metres from the base.
The beam aerial consists of an array of insulated vertical aerials suspended from horizontal supports, known as Triatics, attached to the ends of the cantilever arms, of the 3 masts. Behind the aerials in the centre of the line of masts, are supported a similar structure, which acts as a reflector. In the Anglo-Australian system there are 32 active aerials spaced in a line at right angles to the direction of propagation with a second line of 64 reflector aerials. Aerial arrays are provided in front of, and behind, the reflectors and may be selected at will in order to provide for operation in either direction.
This meant that the signals could be directed or received via either of the great circle routes, depending on the time of day, with little loss of operating time.
The receiving stations use a similar type of aerial, with the advantage that the receivers are screened from radiation emanating from sources outside the area of reception, and this feature greatly reduces, and in many cases eliminates, atmospherics.
This type of aerial can also be utilised for the simultaneous transmission or reception of telephone and telegraph messages without mutual interference, and is also used for facsimile transmission over the beam service.
The Antenna array at Poldhu, Cornwell
The total power consumed by the beam aerial is 20 kW. The separate aerial wires are connected to the transmitters by concentric copper tube feeders and each aerial is separately fed with the same amount of energy.
Considerable attention has been paid to the maintenance of constant frequencies, and for this purpose, the Franklin drive is used, which is capable of holding the carrier frequency constant irrespective of wide atmospheric and temperature variations and it also incorporates a device which can be made to vary the carrier frequency within controlled limits on either side of the mean frequency. A variation of frequency to a width of 300 cycles on either side is employed, and this "wobbling" has been particularly valuable in the reduction of fading.
At the receiving end fading was further reduced by the spaced aerial method of diversity reception. Double superheterodyne receivers were employed, signals being amplified on the signal and on two intermediate frequencies. The signals were fed into the city office in Melbourne at radio frequencies where they were converted into direct current signals for the operation of high speed undulators, which had been found to afford the only practical means of coping with the high speeds common in the beam operation.