Home | Back to Wavescan Index

"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 N582, April 19, 2020

Paraguay on Mediumwave

In our program three weeks back we presented our initial program regarding the radio scene in the South American country of Paraguay. In that program, we focused on the origins of shortwave broadcasting in this, one of South America's smaller countries, beginning in 1935.

In our program today, we cover the longwave and mediumwave story beginning way back around the era of World War I. Back then, as in so many other countries around the world, the army in Paraguay experimented with wireless transmissions in what we now call the longwave band. These transmissions in Paraguay were all in standard Morse Code, though with variations according to the needs of the language in use at the time. Sometimes there were difficulties for those who were using the local languages and dialects in wireless transmission.

Next on the communication scene in Paraguay were the amateur radio operators, who were experimenting with the transmission of voice and music. The very first successful transmission of music in Paraguay was presented on shortwave in 1922 by station CXZ27, which was operated by Alfonso Star and Ernesto Stricke in the capital city, Asuncion. This low power historic radio broadcast of music and news was heard in San Bernadino, some 30 miles distant.

During the next four years, there were several radio stations licensed in Paraguay, mainly in Asuncion, and they each operated under a regularly issued callsign in the form of the two initial letters ZP followed by a number. However, none of these early stations survived into longevity, due mainly to lack of sufficient funding.

For example, one of these somewhat temporary stations was Radio Cultura ZP1, with its studios in Asuncion. This station was inaugurated in 1926, and on March 17 a special concert program was broadcast from the Presidential Palace. The details of this pioneer broadcast were featured next day in the daily Spanish language newspaper in Asuncion, El Orden.

However, due to the paucity of quality programming over the few available mediumwave stations in Paraguay back in the 1930s, many of those people who had sufficient resources to own a radio receiver would tune in to the radio programs that were on the air from nearby Buenos Aires in Argentina. Very popular with Paraguayans were the long musical concerts from Buenos Aires, both live and recorded. In fact, several notable musicians in Paraguay traveled to Buenos Aires in order to perform in radio broadcasts that could be heard back in their homeland.

Due to the European War, and also to variable circumstances within Paraguay itself, the government cancelled all radio broadcasting licenses in 1941, all except for Radio Caritas ZP11, with just 250 watts on 1200 kHz. Then, during the following year (1942), the government established its own radio broadcasting system under the title Radio Nacional.

During the later war years there were half a dozen mediumwave stations on the air in Paraguay. Then, from that time onwards, the number of mediumwave stations throughout Paraguay has gradually increased, almost quite regularly until today. In spite of the introduction of FM broadcasting in the 1990s, the WRTVHB still shows a list of 51 mediumwave stations on the air in Paraguay, surprisingly more than at any other time in the entire history of the country.

Currently, Radio Nacional provides nationwide coverage with the same programming via two mediumwave channels, 920 kHz and 700 kHz. The main station in the Asuncion area is ZP1, with 100 kW or 20 kW on 920 kHz; and the relay station located at Pilar, almost against the border with Argentina in the south west of the country, is ZP12, with 12 kW on 700 kHz.

The radio broadcasting station with the longest continuous history in Paraguay is Radio Caritas, which was inaugurated in a building on the property of the San Francisco Church in Asuncion on November 21, 1936. This early Radio Caritas, with its locally made transmitter, was inaugurated by the Franciscan Priest Luis Lavorel under the registered callsign ZP11, and it was on the air with educational and religious programming mainly for the benefit of local children.

In 1986 the studios were transferred to a new location at 364 Calle Luis A. Herrera, still in the capital city area. At that same time, a new 10 kW Tramec transmitter from Buenos Aires, still on the same 1200 kHz, was installed at suburban Nemby.

Then six years later again, on March 2, 1992, Radio Caritas ZP11 inaugurated a completely new mediumwave station, with a 10 kW Lensa transmitter from Chile and a new quarter-wavelength antenna standing at 360 feet tall. During the year 2000, the studios were transferred to the Catholic University in Asuncion. The programming link from studio to transmitter is a standard low power FM transmitter.

For a period of some 18 years, Radio Caritas also operated a shortwave transmitter, ZPA11, at its mediumwave location at Nemby. Shortwave programming on ZPA11 was always in parallel with the mediumwave transmitter ZP11. The shortwave transmitter was a copy of an old Collins unit made locally, and it operated with 1.5 kW on 6110 kHz.

Mediumwave Radio Caritas is still on the air to this day, and it now operates with 50 kW on 680 kHz. The studios are installed in the Catholic University in Asuncion, and the transmitters are located at Nemby, some 15 miles out.

More about the radio scene in Paraguay next time, on shortwave since World War II.