Cold War radio jamming

Overview
Both the USA, Cuba, the USSR, N. Korea (DPRK), S. Korea (ROK), People's Republic of China (PRC) and the  E. Germany (GDR) regularly blocked rival nations programs with jamming devices. Most nations have jammed some station at some time in there history.

Radio Romania was one of the fist targets of Soviet suspicion. In the geo-political context in which a new Radio Romania mast, M. Gorky, was built in 1936 in Tiraspol, allowed a greater coverage of the territory of Moldova, the Romanian state broadcaster started in 1937 to build Radio Basarabia, to counter Soviet propaganda. The radio jamming war would later develop in to a major Cold War issue.

The Americans launched the station Radio Free Europe while Western broadcasts were launched in the Eastern bloc with the start of the Cold War.

The USSR made heavy use of radio jamming to prevent its citizens from listening to political dangerous broadcasts from the British Broadcasting Corporation (BBC) and the Voice of America (VOA) and other western broadcasters. By 1952, there were approximately 200 jamming stations with a total between 3 and 4 megawatts of output power, which expanded to about 1700 transmitters with a combined 45 megawatts of output power by the early 1960's. The total electricity consumed along with the site construction and personnel costs was enormous.

The concept
It is the deliberate broadcasting of man made interference or one's own transmissions on top of a rival's frequency with enough strength as to smother there transmissions and stop it from being heard. Radio jamming is achieved by transmitting radio signals of one's own station or a jamming device on the same frequency as the intended target.

The operating transmitters for domestic radio stations on the same or nearby frequencies was a routen thing in the GDR (E. Germany). For example, for many years East Germany operated at Wiederau a transmitter on the same medium wave frequency (575 kHz) that Mühlacker radio transmitter used with an output power of 100kW, which made it difficult to receive the AFN Mühlacker radio transmitter in much of the East Germany.

The use of formal and informal and informal jamming techniques lead to a so called transmission "power race" in which broadcasters and jammers alike repeatedly increased their transmission power, utilised highly directional antennas and/or added extra frequencies (known as "barrage" or "frequency diversity" broadcasting) to the already heavily overcrowded shortwave frequency spectrum. This was happening to such an extent that many broadcasters not directly targeted by the jammers (including pro-Soviet stations) suffered from the rising levels of noise and interference for western stations or Soviet jamming devices spilling in to there frequency zone.

Techniques used to jam signals also included smothering them in a maliciously generated signal containing things like loud hissing noises, music or the playing of domestic broadcast tapes backwards on reel-to-reel recorders.

History
The Cold War led to increased international broadcasting, most of which contained either news, sport, music or propaganda disguised as news; as Communist and non-Communist states attempted to influence each other's domestic population.

The Voice of America, the BBC World Service, the (then covertly) CIA-backed Radio Free Europe/Radio Liberty, Radio Havana Cuba international, Radio Moscow and Radio Peking all jostled for the attention and political loyalty of the global public.

W. Germany (the FRG) resumed regular shortwave broadcasts using Deutsche Welle on May 3, 1953. RDW's Julich transmitter site began operation in 1956, with 11 100-kW Telefunken transmitters and the later Wertachtal opened in 1972 and began operating with 4 500-kW transmitters.

Meanwhile, East Germany's Nauen site began transmitting Radio DDR, which later Radio Berlin International, on October 15, 1959. In 1963, a local radio station favoring Moscow city and oblast was also launched.

From the early 1970s, satellites generating frequency swinging carrier signals were used to even better at interfering with rival nation's broadcasts. Nevertheless, the oppressed people continued (or attempted) to listen to Western broadcasts. The Soviets stopped jamming outside broadcasts, excluding Radio Free Europe, from 1963 to 1968 and from 1973 to 1980. The jamming ended in 1988, except for Radio Free Europe was,who had to wate until the August of 1991.

The radio organisation of the USSR began to shut down as private services were introduced in the 1980's which lead to the USSR's stations being relaunched and content refocused.

By 1989, there were 15 RDW transmitters in W. Germany, 4 of which relayed the Voice of America.

In the case of some major broadcasters such as the BBC World Service,Voice of America or Radio Australia, there is also an educational outreach.

Soviet targets

 * Radio Free Europe.
 * Radio Liberty.
 * Voice of America.
 * BBC World Service.
 * Deutsche Welle.
 * Raadio vabadus Eesti- ja Liivimaal (An ethnically Estonia Swedish individual and a couple of friends who were operative in 1947 and 1948 on a narrow amiture SW frequency).
 * Radio Beijing (occasionally).
 * Radio Tirana (occasionally).
 * Radio Vaticana (occasionally).
 * Kol Yisrael  (occasionally).
 * Radio Canada International (occasionally).

The jamming usually only took place during programming in languages widely spoken in Eastern Bloc countries (e.g., Russian, Polish, Czech, German, Lithuanian, etc.). Programmes in English or other major Western languages were rarely (if ever) jammed intentionally.

East German targets

 * Radio Free Europe
 * Radio Liberty
 * Voice of America
 * BBC World Service
 * Deutsche Welle

German, Russian and occasionally English language broadcasts were jammed.

W. German targets

 * Radio Berlin International (occasionally)

German language broadcast were targeted.

Chinese targets

 * Voice of America
 * BBC World Service
 * Radio Free Asia
 * All Taiwanese services
 * Radio Moscow (occasionally)

Drumming, or other noise, Chinese folk music and hissing noises were used as jamming signals.

USA targets

 * Radio Pyongyang
 * The Cuban Atención covert numbers station
 * Radio Havana Cuba international
 * Radio Moscow (occasionally)

UK targets

 * Radio Pyongyang.
 * Radio Moscow (occasionally)
 * Radio Beijing (occasionally)

The usual jamming signals were buzzing, chugging, clicking, whisteling, wiring and hissing noises.

Cuban targets

 * Radio Marti
 * Voice of America
 * BBC World Service

N. Korean targets

 * KBS Radio 1 (obsessively)
 * KBS Radio 2 (obsessively)
 * KBS 2FM 89.1 (obsessively)
 * KBS Radio 3 (obsessively)
 * KBS Radio Social Education (obsessively)
 * Korean Forces Network
 * KBS World Radio (obsessively)
 * South Korea's clandestine shortwave broadcast, Echo of Hope (obsessively)
 * Voice of America
 * Free North Korea Radio (which originates from US transmitters in Guam) (obsessively)
 * Radio Free Asia
 * NHK
 * The British Lincolnshire Poacher covert numbers station is smothered out by Radio Pyongyang operating on exactly the same frequncy.

Before the inter-Korean treaty of 2000 KBS Radio 1 used to deliver certain programmes (merged with then KBS Radio Social Education) which condemned the North Korean regime at midnight each day.

The type of the jamming North Korea uses on shortwave is a 'Jet Plane Noise', which makes it very hard to hear the radio broadcasts. North Korea also jams. The coastal parts of Gyeonggi Province, Incheon, Chungcheong, and sometimes Jeolla regions has KBS Radio 1 Seoul (711 kHz) broadcasts intermittently jammed by strange beeping sounds, which seem to be jamming signals issued by the DPRK. Jamming is only used against Korean language services.

It is still illegal for North Koreans to listen to anything other than state-run radio all all radios sold by state shops in North Korea are pre-tuned to only government stations. Some illegal radios capable of receiving foreign broadcasts can be bought on the black market, but the penalty for being caught was and still is at best several years of misery in a gulag, if not in many cases, an arbitrary execution with in a few day of arrest.

Because of electricity shortages in North Korea, the radio jamming and broadcasting activities are not always consistent and are sometimes interrupted by power failures.

S. Korean targets

 * Radio Pyongyang (obsessively)
 * PBS Pyongyang (obsessively)
 * KCBS Wiwon (obsessively)
 * KCBS Pyongyang (obsessively)
 * KCBS Haeju (obsessively)
 * NHK (obsessively)
 * All other Japanese services

The South Korean government broadcasts several bizarre-sounding jamming sounds which are usually warbling or chugging noises. Jamming is crappy due to 20-50MW S. Korean jammers fighting against a roughly 500MW Radio Pyongyang signal.

In Seoul, Incheon and Gyeonggi Province or near the DMZ has these strange signals on several MW frequencies, mixing with the stronger members of the North Korean radio broadcasts.

According to the National Security Act in South Korea, it was and still is technically illegal to tune into or publish frequencies of North Korean and Japanese broadcasts since they obsessively hate both nations. It is known people cannot be easily caught and/or punished for just listening to those broadcasts individually in a private place. However, the public listening and distribution of recordings of the programs are a prosicutable criminal offences.

Also see

 * The anti-communist "Revolutions of 1989"
 * Life under communism