Adrian Peterson’s Diary, September 1996
Radio Australia, Carnarvon: R.I.P.
As a result of budgetary restrictions, Radio Australia closed its shortwave relay station located at Carnarvon in Western Australia effective June 30, 1996. The service formerly carried by the 300 kw. transmitter VLK at Carnarvon is now on the air over the 250 kw. unit at Darwin designated as VLT. The 100 kw. VLL transmitter at Carnarvon is being moved to Shepparton in Victoria, and the 250 kw. VLM sender will be re-installed at Darwin. Carnarvon is the 6th shortwave transmitter base operated by Radio Australia to leave the air in the past 50 years.
On Christmas Eve, 1974, Cyclone Tracy, the worst ever recorded in Australian history, hit Darwin in the Northern Territory and destroyed 80 percent of the city. Although the structures at Radio Australia’s relay base near Darwin had been designed and constructed to withstand the effects of a cyclone, part of tne antenna system was blown down, and salt water damaged the transmitters. In order to safeguard tne electronic equipment, the station was taken off the air and closed down soon after the cyclone began. It remained off the air for some 10 years.
Because of the damage to the Darwin installation, a temporary fill-in station was immediately necessary. Site investigations were made in Western Australia, and three unused space-tracking stations were considered as possible locations for new and temporary transmitters. These possible sites were Dalwallinu, Gnangara, and Carnarvon. In order to assess the suitability of these areas, a series of test transmissions on behalf of Radio Australia was conducted from Gnangara.
The Gnangara facility was an old OTC station erected when NASA operated a satellite station on the island of Mauritius. Gnangara was established as a relay link between Mauritius and the Australian satellite receiving station at Moree in New South Wales. A landline connected Gnangara to Moree, and three transmitters, each of 7.5 kw., were used for reverse traffic to Mauritius.
Over a period of three weeks beginning on February 25, 1975, a series of test transmissions on behalf of Radio Australia was made from Gnangara using two transmitters and a set of rhombic antennas. Test tapes consisting of long segments of recorded music, interspersed with Raaio Australia identification announcements, were produced in the Melbourne studios of RA for these special transmissions.
The test transmissions from Gnangara were successful, and they demonstrated that signal propagation into the target areas of Asia would be adequate from Western Australia. Government approval was granted for the erection of a new and temporary station at a suitable location along the coastal area of Western Australia.
The next step was to choose a specific site for the new and temporary station in Western Australia. It was important to get the station on the air as soon as possible, and locations with existing facilities were surveyed.
Again, the three main sites were considered. These were the OTC-NASA facility at Gnangara, from which test broadcasts had been radiated earlier; the unused space station at Dalwallinu; and tne NASA satellite tracking station at Carnarvon. The radio facility at Gnangara, near Perth, and the Dalwallinu facility, had several advantages, but a site further north was more desirable propagationally.
NASA, the American space agency, made their abandoned space station at Carnarvon available for the project. Details regarding the new Radio Australia station were announced on April 21, 1975. It was decided at this stage to utilize at Carnarvon one of the three 100 kw. Harris Gates transmitters originally purchased for a new Northern Territory domestic service. The other two were subsequently installed at Shepparton and are on tne air to this day. Bids were sought world wide for a 250 kw transmitter, the associated antenna system, transmission lines and switching gear.
The station site at Carnarvon was delightfully situated on Brown Range, a low, undulating ridge just seventy feet above sea level, four miles Southeast of Carnarvon and three miles from the coastline of the Indian Ocean. The former NASA administration building, selected to house the transmitters, was reinforced for added protection against cyclones. Radio Australia’s 36th anniversary (December 20, 1975) was set as the target date for the first broadcast from the new station.
The main transmitter was a 250 kw. Brown Boveri unit with driven tuning, and the other was an automatically tuned Harris Gates 100 kw. unit. The 250 kw. transmitter, designated No. 1, or VLK, began unofficial test transmissions early in December 1975. On December 20, the scheduled target date, regular broadcasting began with the relay of programs from the Melbourne studios of Radio Australia to Asia.
The five-mast antenna system was completed a few weeks later when tne last of the four bays was erected. There were four curtain arrays using folded half-wave dipoles. Each antenna was designed to operate on any of three adjacent shortwave broadcasting bands. The main bearing of the antenna system was 347 degrees, covering Southeast Asia and Indonesia, but each antenna could be electrically slewed 22 degrees in either direction. The entire antenna system could be lowered to the ground in the event of an approaching cyclone.
On February 15, 1976, the 100 kw. unit designated No. 2, or VLL, came into operation for test broadcasts. Programs from the studios in Melbourne were sent by microwave relay to Perth, and thence by coaxial cable to Carnarvon. These lines are designated VLK for Transmitter 1, VLL for Transmitter 2, and VLM for Transmitter 3.
The Radio Australia relay station at Carnarvon in Western Australia, originally intended as a temporary facility, was on the air for over 21 years. Radio Australia has been on tne air from a total of nine different transmitter locations since it was inaugurated in 1939, and with the closure of Carnarvon that leaves only three still active: Shepparton in Victoria, Darwin in the Northern Territory, and Brandon in Queensland.
A station that is no longer on the air is the Voice of America relay station in Mason, Ohio. Located 26 miles north of Cincinnati, it was just a mile down Tylersville Road from the former VOA-Bethany site.
It was in April 1921, just a few months after the inauguration of KDKA, that the Crosley Corporation launched its first radio station. It operated with a power of 20 watts, and was located in the home of its founder, Powell Crosley, in Cincinnati. The callsign for this new station was the well-known WLW. From this modest beginning, the Crosley Corp-oration has developed a multiple-facility system of MW, FM, TV and shortwave stations.
In 1933, the FCC authorized the construction of a 500 kw. superpower transmitter for WLW. This huge experimental transmitter of half a megawatt output was installed at the new MW home of WLW on Tylersville Road. The antenna, 831 feet high, was one of the world’s tallest structures at the time, being just a little shorter than the Eiffel Tower. The new transmitter bore the experimental callsign W8XO, and began after-hours on-air testing in February 1934. Programs originated in the city studios of WLW, and were broadcast on the normal daytime channel of the regular 50 kw. WLW on 700 kilohertz.
The 500 kw. transmitter of W8XO-WLW was established to determine the feasibility of erecting a small network of superpower MW stations for nationwide coverage over the entire United States. It was heard in virtually every country of the world, and was on the air until the early days of World War II. It’s slogan, “The Nation’s Station,” epitomized its valuable role in pre-war broadcasting. Some years ago one of the station engineers stated that the power output of this superpower 500 kw. transmitter was increased at times until it was actually emitting 1,200 kw., or 1.2 megawatts.
The first shortwave broadcast from this Crosley location was in 1925, when a small 50 watt transmitter was installed in conjunction with the MW unit. It was given the experimental callsign W8XAL. A second unit of 250 watts was added at WLW later that year, to be replaced several years later by a 10 kw. unit. At the onset of the international emergency in 1939, the experimental callsign for 10 kw. SW W8XAL was regularized with a new callsign, first WLWU, and six weeks later the more familiar WLWO, and the 10 kw. transmitter was soon upgraded to 75 kilowatt output.
On February 24, 1942, all private shortwave stations in the United States were taken over by tne Federal government and incorporated into the Office of War Information-Voice of America network. Station WLWO joined this international shortwave network in support of the war effort. On July 3, 1943, a second shortwave transmitter of 50 kw. was installed at Mason. It was a converted MW unit, identified with the subsidiary callsign WLWK. These two transmitters were on the air in service with VOA for 11 years, until 1954, when the newer VOA-Bethany took over this international shortwave outreach.
The radio facility at Mason spawned two other radio services at the same location. In 1936, the engineering staff constructed a small working-model radio station with a power output of just .4 of a watt. The imaginative callsign of the station was WEE. This little unit was a striking contrast to massive 500 kw. WLW in the same building. WEE was demonstrated at the Electronic Exhibition in Baltimore, Maryland in 1936. It has long since vanished, and nothing of it remains today. However, its very large counterpart, the huge 500 kw. MW unit, survives, at least as an empty shell, in the rear basement area of the current transmitter building of WLW Cincinnati.
The other transmitter of interest at this location was a 1 kw. SW unit under the callsign KQ2XAU. It was operated by Crosley on behalf of the National Bureau of Standards at the time they were searching for a more suitable location for their time signal station WWV. KQ2XAU took a relay of the time and frequency broadcasts from WWV, which then was located in Greenbelt, Maryland near Washington, DC. This time signal relay service was on the air from Mason, Ohio on 6080 kHz. from 1947 to 1951.
Tabulated History–VOA Mason
|1921 April||MW||20 watts||WLW||1st Crosley MW station|
|1925||SW||50 watts||W8XAL||1st SW unit installed at Mason|
|1925||SW||250 watts||W8XAL||Second unit added|
|SW||10 kw||W8XAL||New unit replac. 2 older units|
|1934 Feb||MW||500 kw||W8XO||700 kHz, megapower|
|1936||MW||.4 watts||WEE||Demonstrated at Baltimore, MD|
|1939||SW||10||W8XAL||Became WLWU, then WLWO|
|1942 Feb 24||SW||10||WLWO||Joined OWI-VOA|
|SW||75||WLWO||Upgraded to higher power|
|1943 July 3||SW||50 kw||WLWK||2d xmtr added, Mason|
|1944 July 1||SW||200 kw||WLWL||1st new xmtr at Bethany|
|1947||SW||1 kw||KQ2XAU||Experimental time sig relay|
|1954||SW||VOA||Closed, replaced by Bethany|