The HF Communication Stations of Sydney
by Roger Meyer
One of the Department's establishments which outwardly changed little over 40 years was the International Transmitter Station at Llandilo, NSW. Now operated by Airservices Australia, it is situated some 50Km west of Mascot and near the town of St Marys.
Mr Ron OBrien, who was the Officer-in-Charge of the station between 1959 and 1980, recently conveyed the story of this remarkable facility and its origins. We are indebted to his keen memory for an account of how the station came into being.
The first High Frequency (HF) transmitting station for Sydney was at Brighton-le-Sands, near the shore of Botany Bay. Post-war expansion of Sydney/Kingsford Smith airport involved diverting Cooks River through the transmitter site. It was therefore decided to build a new transmitting station for domestic services at Randwick, and an international station at Richmond.
In 1948, the RAAF gave DCA permission to share their building at Londonderry. DCA engineers Ron Rye and Eric Anderson planned the installation of four 5KW transmitters which had been recovered from Stonecutters Bay in Hong Kong, and two Marconi SWB-8 3.5KW transmitters acquired from the Army. (One of these magnificently engineered brass SWB-8 transmitters has been beautifully restored at the Airways Museum in Melbourne).
With the commencement of the Korean War in 1950, DCA was requested to vacate the Richmond site in order that the RAAF might install additional transmitters for their own use. They offered DCA a site of 15 acres at Bass Hill, which included a temporary fibro-cement building. The floors had to be strengthened and the doorways enlarged before the transmitters could be moved there from Londonderry.
DCA used the Bass Hill site for nine years, during which time international radio teletype circuits were introduced. Under pressure from PanAm, radio telephone and selcal circuits were hurriedly installed so the airline could do away with aircraft radio operators. In the end, the station was operating a grand total of 18 transmitters.
Conditions were deplorable. There was no air conditioning, and when all the equipment was operating, the heat was unbearable. All of the station earth wires came alive with induced radio frequency energy - you could get RF burns even from the buttons on the telephones. The aerial system became a jumble of wires. Even the birds complained!
Why did DCA spend nine years at Bass Hill? The intention was to purchase land at St Marys and relocate the facility there, but someone in Head Office acquired the wrong area of land. Surveyors found that the Department had acquired the entire village of Llandilo. The Town Clerk of Penrith understandably became very upset because the Commonwealth, which did not pay rates, had purchased the village.
It took over two years to cancel the acquisition and proceed with purchasing the correct parcel of land. Another three years passed before the new acquisition became legal. Actually, the delay was a blessing in disguise. Building restrictions after the war required new buildings to be of timber construction. Finally, the building restrictions had been lifted and the building of Llandilo was carried out in bricks and mortar. The land was approximately two square miles in area (1280 acres), but we ended up using only a small portion of the available area. The building complex occupied part of the land, with the remainder being used for the rhombic directional aerials.
Sydney's HF transmitter station at Llandilo, photographed in 1963. Click here to see more photos of Llandilo. (Photo: CAHS collection)
When the station was opened on 10th March 1959, the ABC informed us that we had blocked out the ABC TV channel to the west of Sydney. It was found that the teletype circuit to Manilla was radiating the offending harmonic frequency. The problem was resolved, but for the next 24 years there were constant investigations into interference. We were blamed for all radio interference problems.
Why was the name changed from St Marys to Llandilo? Around 1960 a huge ammunition factory was built nearby. The factory was not popular, and the Minister for Civil Aviation (Senator Paltridge) did not want our establishment tarnished with the name of St Marys. The nearest Post Office was at Llandilo, so that was the name adopted for our transmitter station.
The station, as installed, was the voice of Sydney Aeradio for communicating with aircraft operating to and from Sydney in the South-West Pacific and on overseas flights via Perth and Darwin. High-powered teletype links operated to Honolulu, Nandi, Singapore, Manilla, Biak, Melbourne, Brisbane, Cloncurry and McMurdo Sound in the Antarctic. The teletype circuits despatched aeronautical flight information, weather advice forecasts, notams and other point to point traffic information. These services conformed to ICAO requirements for international airline operations.
The bulk of the large area of land used was for ten rhombic aerials. These were large diamond shaped antennas supported on 100 foot guyed steel towers and oriented along a major axis, approximately 1,200 feet long, pointing in the direction of the distant station along a great circle path.
In its heyday, there was a large staff at Llandilo. Radio technicians, electricians, mechanics, linesmen, a storeman, a painter and administrative staff about 40 in all - maintained Llandilo and a number of sites to the west of Sydney.
In the control room of the main building is an impressive brass plaque in memory of Warwick Flynn, a former Regional Supervising Airways Engineer. Before he died, Mr Flynn requested that his ashes be spread over the ground at Llandilo. The Regional Director gave permission, and Ron OBrien organised a simple ceremony. The station flag was lowered to half-mast, the family gathered on the lawn and staff on non-essential duty gathered around the flag. Senior Airways Engineer John Abel was in a DCA aircraft and scattered the ashes as the aircraft flew over the site. On completion of the last run there was a call for one minutes silence. The family was then invited to afternoon tea and a tour of the station.
Today Llandilo has a staff of thirteen and maintains facilities in the area bounded by Wollongong, Newcastle and Orange to the west. Undersea cables and satellite communications have replaced the teletype services, and 10 KW transmitters now provide an air-ground service to aircraft within a range of 3,000 Km from Sydney Airport.
(Photo: CAHS collection)
Click here to read about the HF Communication Stations of Melbourne