Radio is one of the most effective ways of communication. The information that travels around the airwaves can reach even the most remote places. In late 20 century twenties it was discovered that by transmitting in High Frequency band (1,6 Mhz-30 Mhz) or so-called shortwave the signal can reach every radio receiver in faraway countries. In so the shortwave radio became effective way for government propaganda. And regimes that disliked that their citizens can listen to foreign broadcasts searched for ways how stop this.
During the first Soviet occupation in 1941, the Soviets started the registration of the radio owners. They wanted to know how many and what kind of people could listen to foreign broadcasts, and impose license fees for radio using and in case of need take them away from the owner. During the Nazi Germany occupation a list of suppressed radio stations was made.
In 1945 the Soviet occupation returned. Everywhere in Latvia people gathered at their radio receivers and waited for the news of coming American and British liberation, however soon the frequencies of the foreign stations became filled with load roaring noise. The era of the Soviet radio jamming had begun.
On 1946 USSR Communications ministry issued an order to register the radio receiver in whole country. On the streets of the cities and main squares loudspeakers were placed to transmit the propaganda from radio stations from Riga and Moscow. It was nearly impossible to purchase the radio receiver after the war, so the radio transmission points were placed in the apartments. It had strategic goal because now the government could inform the people about its decisions and orders.
As the Cold War became more intense the Western countries begun to transmit broadcasts to Soviet Union in various languages including Latvian. The main broadcasters were the Voice of America, BBC Word Service, Deutche Welle and Radio Free Europe. Radio Free Europe was actually a creation of the US Central Intelligence Agency. CIA secretly financed the RFE for many years until it was discovered by the leftist journalists in 1967 and since 1972 the RFE is financed by the US Congress. USSR also had its own shortwave propaganda station Radio Moscow. However, in Western countries listening to the Soviet propaganda was not considered as a serious crime. In Soviet Union listening to Western stations could cause a real jail sentence.
For instance in 1951 Elfida Jansone was put on LSSR High Court for listening to the Voice of America. For this crime she was sentenced for eight years in labor camp. In 1948 the Latvian Communist party Riga city committee bureau issued a decree “For urgent actions for jamming of the anti-soviet broadcasts”. The decree ordered every institution that had a shortwave transmitter to jam the foreign radio stations. Jamming was done by Latvian Energy, Sea Fleet and Soviet Army. Army constructed 10 transmitters that jammed the foreign voices 24 hours in day. However, the power of these transmitters was too weak to completely silence the foreign broadcasts. Because of this in all three occupied Baltic States a special jamming stations were built.
On May 5 1951 the chairman of the LSSR Council of Ministers Vilis Lācis wrote a note to Vyacheslav Molotov that in accordance to USSR Council of Ministers decree on 4 December 1950, a high voltage radio center was to be built in Riga; however the Ministry of Communications had planned to build it only in 1953. The head of the LSSR asked the Soviet Ministry of Communications to start building this object already in 1951 and finish it in 1952. However, the slow Soviet bureaucracy only in 1953 ordered to build jamming systems in the Baltic States. A jammer was built in Liepaja, Daugavpils and Riga.
All of these special objects were under control of the Latvia republican radio center. American made shortwave transmitter SCR-399 that was delivered by the US in war-time was now used to jam the US broadcasts. The power of these transmitters was not high – only 400 watts however it operated in the 1,5- 1,8 Mhz frequency range that used by the most foreign stations. The object in Liepaja has 12 transmitters and one Russian “Extra” type Medium Wave transmitter (Medium Wave is 526-1600 kHz). In the Riga object at the Dome Square basement had 18 SCR-399 transmitters but at other Riga site 15 Soviet KV-5 transmitters with power of 5 kilowatts were placed. The transmitters were modified with GMD generator that was the most secret part in the objects. This device made various tone sound signal that was nicknamed “saw” by the listeners. It was impossible to filter this noise because its frequency was the same as the broadcasting foreign station. It even made interference in frequencies free from broadcasts. It was a hard time for people living near the jamming stations because the strong signal made inference for allowed radio and TV broadcasts. Before the start of every broadcast one or even two transmitters were allocated to the broadcast frequency and after the command was given the jammer were turned on. Sometimes the in the time of broadcast the stations slightly changed the frequency, leaving the jammer in behind, forcing to retune it. The radio propagation issues also sometimes did not allow silencing the broadcasts completely.
The Medium Wave broadcasts were completely jammed by stations from Lithuania and Estonia. Sometimes the foreign broadcasters appeared at previously unannounced frequencies and the jammer power was not so high so the ordinary Soviet citizen could listen to them.
Despite the warnings and repressions, people listened to foreign broadcasters. Some were tired of the Soviet propaganda, some were just curious. Some understood that they lived behind the Iron Curtain and had enough of censorship and lies. The Latvian radio receiver producers VEF and Radiotehnika were forced to make receivers without the frequency ranges where the foreign broadcasters appeared. The listeners of these stations were reported by the work colleges, neighbors even relatives. While nobody was thrown in the prison since the death of Stalin, being caught of listening to “hateful anti-soviet propaganda” could mean job loss and further sanctions.
Not every foreign broadcaster was considered anti-soviet, as there were many broadcasters from Soviet-friendly countries. The main condemned broadcasts came from Western Europe and US.
The Soviet spy agency KGB tracked the radio listening. It had many radio control points over all country. In 1982 the KGB was even ordered to track the Ultra High Frequency ranges at 30 km zones around the cities. The main ones who were tracked in this range were radio amateurs. In Soviet times every radio amateur was under the KGB watch. The Soviet Military intelligence service GRU installed a mobile tracking and surveillance base in Riga that could listen and record the telephone conversations. After the fall of the Soviet Union the GRU offered to sell these devices to Latvian government.
The shortwave radio jamming in Soviet Union ended when the new Soviet leader Mikhail Gorbachev ordered to stop the “useless spending of money”. Shortwave radio jamming is still practiced by many countries like China, North Korea, Iran and Vietnam. As long there will be a need for political information the shortwave radios and its jammers will not disappear.
Upmalis, Ilgonis, Tiglass, Ēriks, Stankēvičs, Ēriks. (2011) Latvija padomju militāristu varā : 1939-1999.Rīga: Latvijas okupācijas izpētes biedrība.