Private broadcasters targeting North Korea say that the jamming of their broadcast signals has gotten worse since the Kim Jong Eun regime came to power late last year. This, they say, is making it all the more critical that they be allowed to broadcast on higher output MW frequencies.
In theory, the broadcasters' current SW frequencies can be used to reach every corner of the Korean Peninsula with minimal effort, but in reality SW signals are sensitive to weather and geographical conditions. Moreover, the signals are not powerful, making it easier for North Korea to jam them.
Kim Seung Chul, the founder of North Korea Reform Radio, explained to Daily NK, “We frequently check broadcast reception, and the fact is that since April-May the jamming has gotten stronger. There has always been jamming, but recently there has been the sound of more than two jammers, explaining the increased discharge of jamming signals.”
North Korea Reform Radio’s nightly SW 7590khz transmission from 12AM to 2AM reveals that since early June there has been the sound of both a jamming signal and a conflicting radio wave signal emerging from North Korea. Occasionally, as many as four different sounds can be heard.
Kim explained, “In the case of North Korea Reform Radio, when there is no jamming it can be heard just like an FM radio signal, but since the jamming got serious it has become more and more difficult to hear.”
Lee Kwang Baek, the director of Radio Free Chosun, agreed with the claim, saying, “There has always been jamming from the North but it has been strengthened recently.” Noh Young Rae, who directs Open Radio for North Korea, noted, “North Korea’s jamming signal is stronger because it is now coming down multiple paths.”
The Northeast Asian Broadcasting Institute agrees that jamming efforts have been stepped up in recent months. The organization assumes that North Korea has established additional jamming stations on military bases in order to enhance operations.
According to Professor Koh Young Chae, “Jamming is easy. As long as you discharge at the the same frequency as the target broadcast then it can be accomplished. It’s not ‘white noise’ like we often hear on TV; if a regular whirring sound can be heard then that signal is being jammed.”
The broadcasters complain that they cannot deliver broadcasts reliably to the North Korean people as a result of this situation. In particular, they tend to complain that most of the broadcast stations they use are not even in South Korea.
Open Radio for North Korea does transmit on MW using transmitters owned by MBC in Chuncheon, not far from the DMZ, but that is an exception and the signal strength is low, making it unclear to what extent the North Korean people can actually hear it. Experts concur with the broadcasters that the only guaranteed way to get through to the North Korean people is to broadcast from domestic South Korean transmitters using high output MW frequencies.
According to the Northeast Asian Broadcasting Institute, “The broadcast that defectors say they listened to the most is KBS Voice of Korea, and that is because it is transmitted on high output MW frequencies. Jamming requires a frequency strength that is equal to or greater than the original signal, and so if we were to transmit on high output MW frequencies then it would not get jammed.”
Ha Tae Kyung, the founder of Open Radio for North Korea and now a lawmaker with the ruling Saenuri Party declared, “If civilian broadcasters are to provide stable signals then they need the government to allocate MW frequencies to them. To do that requires deliberation by the Korea Communications Commissions and cooperation from opposition lawmakers.”