Radio jamming in Korea

The South Korean government constantly jams most radio broadcasts from North Korea on medium-wave. According to the National Security Act in South Korea, it is illegal to tune into or publish frequencies of North Korean broadcasts. Yet an ordinary South Korean citizen cannot be easily punished for merely listening to those broadcasts in private. However, public listening and distribution of recordings of an anti-government organisation, namely North Korea, are criminal offences. A listener in the Seoul 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 P'yŏngyang), 720 kHz (KCBS Wiwŏn), 819 kHz (KCBS P'yŏngyang) and 882 kHz (KCBS Sinŭiju). It also used to jam transmissions broadcasting from Haeju — for example 1080 kHz (KCBS Haeju) — before transmissions from Haeju were decommissioned. 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). Using a decent quality radio, a listener can sometimes nullify the South Korean jammer by re-orienting the set so its ferrite antenna points in a different direction. On shortwave, jamming is not as severe; only very few North Korean frequencies are slightly jammed. FM jamming is also carried out and it is highly effective in Seoul. Television jamming in South Korea was widespread before the introduction of Digital Multimedia Broadcasting (DMB) in South Korea. In Seoul, one could see color bars on particular channels of the VHF band used by (North) Korean Central Television. Now jamming with random signals on those channels is not done, but the channels are used for DMB broadcasting. The digital broadcasts provide reliable portable digital television multimedia broadcasts, but cause severe interference with the North Korean analogue signals. ==Radio jamming in North Korea==

It is illegal for North Koreans to listen to anything other than state-run radio, and all radios sold by state shops in North Korea are fix-tuned to government frequencies, though radios capable of receiving foreign broadcasts can be bought on the black market. Currently there used to be some strange signals on VHF ch. 9 (KBS1) as well as VHF ch. 7 (KBS2) in Seoul which may be North Korean jamming; the two analogue TV channels were discontinued as of 31 December 2012. This jamming is not very effective and a bigger issue for North Koreans attempting to receive Southern TV is the use of different standards. Due to electricity shortages in North Korea, radio jamming activities are not consistent and are sometimes interrupted by power failures. A group named Free North Korea Radio conducts numerous activities that focus on providing radio broadcasts to North Koreans. The broadcasts often include instructions on methods to leave the country and the group has contact with underground reporters within North Korea. The group primarily consists of numerous North Korean refugees and defectors. In late September 2017, the BBC World Service launched shortwave broadcasts in Korean aimed at the Korean Peninsula from its transmitters in Taiwan and Tashkent, which North Korea quickly began jamming. In July 2025, South Korean President Lee Jae Myung halted five radio channel and one TV channel broadcasts by the National Intelligence Service to North Korea. In the same year, United States President Donald Trump cut funding for services such as Voice of America and Radio Free Asia. These actions together led the number of hours of programming entering North Korea to fall by roughly 80% since May 2025. ==See also==