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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 N549, September 1, 2019

The Mediumwave Radio Scene in Uruguay

In our program two weeks ago, we presented the story of the longwave wireless communication stations in the small South American country of Uruguay; and in our program today, we examine the story of mediumwave radio broadcasting in this same country, Uruguay. Let's go back now almost one hundred years, to the era immediately after the end of World War I. That was the era when radio program broadcasting began to develop most rapidly in many countries around the world, including Uruguay.

Radio history in Uruguay lays claim to the fact that radio station LOR in neighboring Argentina, with its inauguration on August 27, 1920, was the first radio broadcasting station in the world. Well, that's almost correct, but not quite. There were earlier stations in Canada, and the United States, and elsewhere also.

However, during the following year (1921), the General Electric company in South America imported a 10 watt longwave radio broadcasting transmitter from the General Electric factory in New York. It was intended that this longwave transmitter would be installed temporarily as a public display at a Radio Exhibition in Rio De Janeiro, Brazil.

However, due to an import dispute, the transmitter was diverted for import into Buenos Aires, Argentina. Then, due to another import dispute, the transmitter was again diverted, this time for import into Montevideo, Uruguay.

A newspaper report published on August 4, 1922 stated that their new radio broadcasting transmitter would soon be on the air in a government building in Montevideo under the callsign CWOS. Irregular transmitter tests began a week later with the playing of recorded music, and then, on August 15, regular broadcasting began with the transmission of music as well as information by voice.

Soon afterwards another broadcast transmitter was obtained, a 1 kW unit from neighboring Buenos Aires. This unit was installed on the top floor of the Florida Hotel at Calle Uruguay 808 Esquina in Florida, Montevideo, and the antenna towers were erected on the roof of the same building. These towers supported a cage antenna, which was thus 230 feet above sea level.

The official inauguration ceremony for this new higher powered longwave radio broadcasting station took place at 5:00 pm on Sunday, November 6, 1922 with the broadcast of locally presented music and official speeches.

Just three weeks away was Election Day, wherein the citizens of Uruguay would be voting in favor of candidates from any of the ten political parties, though the most prominent were the National Party and the Colorado Coalition. The Colorado Coalition bought all of the available air time on the new radio station, right up until Election Day itself (November 26, 1922), in an endeavor to win the election. (We might add that the impact of the political programming on the new radio station did in fact increase a favorable result for the Colorado Coalition.)

Because of wide band tuning in those days, there was mutual interference for the two stations, broadcasting station CWOS and the coastal communication station CWA, whenever both were on the air at the same time. Thus another new General Electric transmitter was imported from the United States, and this was installed on the roof of the Crandon Institute at the corner of 8 de Octobre and Garibaldi Avenues in Montevideo. This new General Electric station CWOS was now on the air with 500 watts in the American mediumwave band, on 790 kHz, thus ensuring interference free reception.

During the 1920s a multitude of mediumwave radio broadcasting stations sprang up in Uruguay. Most of these stations were located in Montevideo, though a couple were located in Salto, which is located towards the north of Uruguay, right up on the border with Argentina. During this era, each radio station was granted a four letter callsign beginning with the letters CWO. The sequence of these mediumwave callsigns began with CWOA, and they progressed consecutively through the English alphabet, as CWOB, CWOC, CWOD, etc.

The government operated radio network in Uruguay, SODRE (Servicio Oficial de Difusion, Radiotelevision y Espectaculos), was organized on December 18, 1929. This dual system of government and commercial stations is somewhat reminiscent of the similar dual radio broadcasting systems that were established in Canada, Australia and New Zealand.

Due to new international radio regulations, all of the mediumwave stations in Uruguay were granted new callsigns. An official list published in 1934, shows that these new callsigns were made up of the two letters CX, followed by a number. Thus, for example, the first alphabetic listing in the old style of callsign identification CWOA no longer existed; and the first callsign in the new style shows the listing as CX4.

However, at the same time as the new callsigns were implemented, there was also a reshuffle of frequency allocations, and it is thus almost impossible to trace the history of any specific mediumwave station in Uruguay through callsign and frequency history alone. It should be remembered too that as far as the listeners are concerned, the station slogan is far more important than the official government allocated callsign. Online sources though do suggest that the original station CWOS adopted the name Radio El Espectador on May 15, 1931, and its callsign became CX14 broadcasting on 810 kHz.

The first edition of the WR(TV)HB in 1947 shows just one mediumwave station, CX14 Radio El Espectador in Montevideo; and four years later, the 1951 edition lists four of the higher powered mediumwave stations in Uruguay, each with a transmitter power in the range from of 15 - 50 kW. The first complete listing of all mediumwave stations in Uruguay is presented in the 1952 edition, with all ten stations shown, including Radio SODRE and Radio El Espectador.

The current edition of the WR(TV)HB 2019 lists a remarkable total of 89 mediumwave stations on the air in Uruguay, ranging in power from 100 watts to 100 kW. The lowest powered mediumwave station is Radio Libertadores, CW102, with just 100 watts on 1020 kHz at Salto; and the highest powered 100 kW transmitter on 770 kHz carries the programming of Radio Oriental, CX12, in Montevideo.

There are these days three callsign sequences in Uruguay. The callsign sequence CW plus a number begins with station CW1, Radio Colonia, with 25 kW on 550 kHz in Colonia; and the callsign sequence CX begins with station CX4, Radio Rural, with 50 kW on 610 kHz in Montevideo.

A few more recent stations have been allocated a callsign beginning with the two letters CV. Current practice is that the numbers included in the callsign are used to indicate the frequency upon which the station is licensed to broadcast.

One radio authority states that the three most popular mediumwave stations in Uruguay are all located in Montevideo, and they are:

Next time, the Shortwave Radio Scene in Uruguay.