Medium wave jamming is dominant in the area including Seoul and the Korean Demilitarized Zone (DMZ).
According to the National Security Act in South Korea, it is illegal to tune into or publish frequencies of North Korean broadcasts.
However, public listening and distribution of recordings of an anti-government organisation, namely North Korea, are criminal offences.
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.
The type of the jamming on shortwave is "Jet Plane Noise", which makes it very difficult to hear the radio broadcasts.
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.
The broadcasts often include instructions on methods to leave the country and the group has contact with underground reporters within North Korea.