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"Wavescan" is a weekly program for long distance radio hobbyists produced by Dr. Adrian M. Peterson, Coordinator of International Relations for Adventist World Radio. AWR carries the program over many of its stations (including shortwave). Adrian Peterson is a highly regarded DXer and radio historian, and often includes features on radio history in his program. We are reproducing those features below, with Dr. Peterson's permission and assistance.

Wavescan, July 29, 2012

Radio Broadcasting in Ceylon - 7: Radio SEAC Colombo Takes to the Air!

In our program last month, in which we presented another episode in the ongoing story of radio broadcasting in Sri Lanka, we got as far as the 1st SEAC shortwave station located at Ekala, a dozen miles north of Colombo. This first shortwave station at Ekala was a temporary SEAC station, installed in the Royal Air Force radio station, and it was replaced by a much larger adjoining facility soon afterwards. That is our story here in Wavescan today.

Actually, initial consideration for a large shortwave transmitter station at Ekala goes back to the year 1941, when preliminary plans were laid for a shortwave facility to extend the coverage of Radio Colombo, for listeners both in Ceylon, and further afield in Asia. At first, progress on this new station went slowly, but when Admiral Lord Louis Mountbatten came on the scene in 1944, work on this project became a high priority.

The design for the shortwave station in Ekala, Ceylon was very similar to the design for the huge BBC shortwave station located at Tebrau on the Malay peninsula. Much of the electronic equipment was quickly shipped from the Marconi factory in England, but the ship was sunk by a torpedo off the coast of Ceylon. The original antenna towers came from the Isle of Wight, and these were lost also when the ship went down as a result of enemy action.

A 2nd consignment of electronic equipment was shipped out from England, and this was quickly installed into the new transmitter building at Ekala. Provision was made for one shortwave transmitter at 100 kW, an English Marconi model SWB18, and three at 7.5 kW, American RCA models ET4750, one of which was transferred from the RAF transmitter station next door. The antenna system consisted of four curtain antennas and three Krauss dipoles, and these were strung from six tall aerial towers. A total of four diesel power generators were installed in a separate building, three for regular usage, and one as a standby unit.

The SEAC studios, already on the air via the RAF shortwave station at Ekala as mentioned previously, were located in the building at 191 Turret Road, Borella, quite opposite the Town Hall. By the time the large new SEAC transmitter base was ready for on air usage, the suite of studios was well established, with 3 on air and production studios, a control room, and also an equipped radio van for use in outside broadcasts.

The SEAC receiver station was also the RAF receiver station, located at Horahena, some 10 miles distant from the two side-by-side transmitter stations. This receiver facility included two banks of 3 receivers, American RCA receivers model AR88, and the receiving antennas were triple wire directional diamond shaped rhombics. The receiver output was landlined to the studio complex in Colombo, with the main shortwave relay programming coming in from the BBC, London, All India Radio, Delhi, Radio Australia, Melbourne, and the Voice of America in Washington. DC.

It appears that the first unit installed in the new SEAC building at Ekala in 1945 was a new RCA transmitter, model ET4750, rated at 7.5 kW. Test broadcasts from this transmitter went on the air in advance, and it was taken into regular service on May 1, 1946, along with the large 100 kW unit.

Likewise, this 100 kW unit was installed during the latter part of the year 1945, and the 1st test broadcasts were noted in April of the following year. This unit was taken into regular service on May 1, 1946, along with the smaller RCA unit. Both transmitters were officially opened with a commissioning ceremony one week later, on May 8.

Soon afterwards, the low powered shortwave transmitter at suburban Welikada was removed and re-installed at Ekala, and this was inaugurated with 1 kW on 3390 kHz for islandwide coverage. A 4th shortwave transmitter, another American RCA unit at 7.5 kW, was inaugurated at Ekala during the following year.

The officially licensed callsign for the SEAC transmitters was ZOJ, which appears to be a consecutively issued callsign. Apparently, there was a ZOA and a ZOB and a ZOC and a ZOD in some other part of the world. It is known for example that ZOE was the callsign for the shortwave station located on the island of Tristan da Cunha in the South Atlantic. Apparently the Ceylon sequence began with ZOH and ZOI for the local stations of Radio Colombo, and the SEAC call in alphabetic order was ZOJ.

A 10 kW mediumwave transmitter was also installed for SEAC coverage of greater Colombo, and this was inaugurated some time towards the end of the year 1948, under their regular callsign ZOJ. It is not known where this transmitter was located, though we would suggest that it was at either Ekala or Welikada.

The entire SEAC facility in Ceylon was established under the direction of Lord Louis Mountbatten and this era began on October 11, 1944 and ended in May 31, 1946 due to the fact that the SEAC headquarters were already transferred from Ceylon to Singapore. At this stage, the War Office in London took over the administration of the SEAC station in Ceylon, and they ended their oversight of the facility, around the end of the year 1948 or early in the year 1949. However, the changes in the administration of the station had little impact on the actual programming schedule, and during these eras the station always identified on air as Radio SEAC.

Radio SEAC in Colombo Ceylon was always an excellent verifier, and their plain text black and white QSL card was received by a multitude of listeners all throughout the world.

For a period of time as an era of peace began to take over the world, this large and well placed station operated as a regular relay station on behalf of the BBC in London. More about that some time in the future here in Wavescan.