First Shortwave Wireless Telephony Broadcasts
With the rapid development of wireless telephony, due to the invention of the vacuum valve, commercial interests, as well as private experimenters, began to explore the shortwave region of the communication spectrum more than ever before. In 1925, the first Trans-Atlantic wireless telephone contact was made on about 5000 kHz, by Mr J. A. Partridge,

In May 1924, the first wireless telephony broadcasts direct from England to Australia were conducted, and signals were received in Sydney, at the home of Mr Fisk, at Vaucluse.

Beyond doubt, the first international shortwave station was PCJJ, with its experimental broadcasts in the “30 metre band” in 1924, introduced by the late Eddie Startz, in his ageless Happy Station programme. The previous year of  saw the first trans-Atlantic wireless telephone contact on a frequency of about 3 MHz by Mr J. A. Partridge, using the callsign 2KF, in England.

Here in Australia, tests were also being conducted in 1923 by the PMG’s Department. In May 1924, the first wireless telephony broadcasts direct from England to Australia were carried out, and signals were received in Sydney, at the home of Mr Fiske, in Vaucluse. The Marconi station at Poldhu, Cornwall, carried out tests with a power of 12 kW in October 1924, "on 52 metres", and these signals were heard in Sydney, New York, and Buenos Aires.

In January 1925, the American station W8XK, at Pittsburgh, Pennsylvania, "on 65 metres", successfully tested with telephony to Australia, relaying its mediumwave outlet KDKA. Further tests were heard in July 1925, and good reception was reported throughout eastern Australia at around 8.05 pm Eastern Australian Standard Time.

An enterprising private experimenter, Mr Ray Allsop, of Sydney, using the callsign 2RG, relayed the KDKA test broadcasts over the MW station 2BL in Sydney. His own 80 metre amateur transmissions were being heard all over Europe in 1925. By the end of 1925, there were about 50 shortwave broadcasting stations operating internationally, and interest in "wireless" was increasing quickly.

Here in Australia, the experimental transmissions from the American stations were being widely heard. These included 2XAF with 1 kW, early in 1925, and later upgraded to 20 kW on 40 metres; this was the General Electric Company’s station at Schenectady. Other calls heard from this station were W2XAD on 26 metres and W2XAW on 15 metres, all relaying the medium wave outlet WGY.

The period from 1925-1930 saw the introduction of various other American shortwave stations, generally with relays of their mediumwave transmissions.

The prominent ones were W2XE (relaying WABY at New York), W2XAL (relaying WLW), and W6XBE (San Francisco). Some of these experimental shortwave broadcasters were the forerunners of the OWI (Office of War Information) stations, which in turn developed into the Voice of America. Many of these stations arranged special tests for listeners here in Australia, and were generally well received.  

The higher powered Russian transmitter located at Khabarovsk, with the callsign RFW using “”66 metres”” was another station that was being widely heard in Australia with good signals. It was most often reported during the evening hours, around the years 1925/1926.