Monday, December 29, 2008
RADIO JAMMING IN KOREA

Radio jamming on the Korean Peninsula makes the border region one of the world's busiest places for radio signals. MW jamming is dominant in the Korean Metropolitan area including Seoul and the DMZ (the border area between South and North Korea). South Korea jams broadcasts from North Korea, but does not jam broadcasts from other countries. However North Korea jams both South Korean broadcasts and foreign shortwave broadcast services which it believes to be against the North Korean regime. These include the Korean-language service of the Voice of America (VOA), Free North Korea Radio (which originates from US transmitters in Guam), and several other services and broadcasts.

Radio jamming in South Korea

The South Korean government constantly jams most radio broadcasts from North Korea on medium-wave. According to the National Security Law in South Korea, it is illegal to tune into or publish frequencies of North Korean broadcasts. Despite the fact, one cannot be easily punished for just listening to those broadcasts individually. However, public listening and distribution of the recordings are criminal offences. A listener in the South Korean Metropolitan area (Seoul, Incheon, and Gyeonggi Province) or near the DMZ who tunes across the MW band may hear strange signals on several MW frequencies, mixing with North Korean radio broadcasts. These include 657 kHz (PBS Pyongyang), 720 kHz (KCBS Wiwon), 819 kHz (KCBS Pyongyang), 882 kHz and 1080 kHz (KCBS Haeju).

The South Korean government broadcasts several bizarre-sounding jamming sounds (usually warbling or chugging) in an attempt to prevent their citizens from hearing radio broadcasts from the North. The medium-wave jamming by the South is sometimes too weak to completely block the North Korean broadcasts (the jamming transmission power seems to be between 20 and 50 kilowatts, while the targeted North Korean transmissions are of much higher transmission power -- typically over 500 kilowatts).

Radio jamming in North Korea

Since it is illegal for North Koreans to listen to anything other than state-run radio, all legal radio receivers are sold fixed so they can play only channels approved by the government. Because the receiver channels are fixed, North Korea does not need to jam any South Korean private television and radio broadcasts (such as MBC, SBS, etc). North Korea does jam some of South Korea's state-owned radio and television broadcasts. Before the (early 2007) closure of South Korean shortwave domestic radio broadcasts (which were often targeted at the North) 3930 kHz KBS Radio 1 and 6015 and 6135 kHz KBS Radio Korean Ethnicity (formerly KBS Radio Social Education) had been severely jammed by the North.

The type of the jamming on shortwave is 'Jet Plane Noise', which makes it very hard to hear the radio broadcasts. North Korea also jams South Korea's clandestine shortwave broadcast, Echo of Hope, and the South Korean international shortwave broadcasts of KBS World Radio on 5975 kHz (discontinued as of early 2007) and 7275 kHz. The South Korean national radio channel, KBS Radio 1 on 711 kHz medium-wave is also jammed by the North. Before the bilateral declaration in 2000, KBS Radio 1 used to deliver certain programmes (merged with then KBS Radio Social Education) which condemned the North Korean regime during at midnight. A visitor to coastal areas of the Yellow Sea (covering coastal parts of Gyeonggi Province, Incheon, Chungcheong, and sometimes Jeolla regions) who tunes into 711 kHz (KBS Radio 1 Seoul) may hear strange beeping sounds, which seem to be jamming signals from the North.

Strangely, the North does not usually jam the medium-wave transmissions of South Korea's broadcast towards-the-North, KBS Radio Korean Ethnicity (formerly KBS Radio Liberty Social Education) on 972 and 1134 kHz. It should be noted that KBS Radio Korean Ethnicity actually no longer targets North Koreans since the North-South Korea Joint Declaration on 15 June 2000. As of 15 August 2007, the radio channel has changed to a special radio broadcast for ethinic Koreans in Northeast China and Far Eastern Russia.

North Korean jamming of television broadcasting is relatively unusual, although the North Korean regime once severely jammed a South Korean state-owned television broadcast (KBS TV1 on VHF ch. 9 in Seoul) in the 1970s. Currently there seem to be some strange signals on VHF ch. 9 in Seoul which seem to be North Korean's jamming, especially in the evening. This jamming is not very effective.

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