"Chinese jamming and monitoring station"

China jams Chinese/Tibetan/etc. programs of SOH (Sound of Hope), VOA, RFA, BBC, AIR and so on. There are two types of jamming; “Firedrake” (musical jamming) and CNR-1. They use both Firedrake and CNR-1 to jam
the in-band broadcast, while only Firedrake is used to jam off-band program such as SOH. Based on monitoring by NDXC members and directional analysis, jamming come from multiple sites – there is no site used for jamming only. Thanks to mis-transmission and directional analysis, we found that some transmitters in Hainan, Xian, Qiqihar and Kunming are used for jamming. The jamming is “controlled” by Radio Control Bureau of SARFT – The State Administration of Radio, Film and Television”, and the jamming is monitored by Radio/TV monitoring
stations – one of the monitoring station (#573 monitoring station) is located north of Beijing . It is reported that Radio/TV monitoring stations are also located in Shanghai, Xinjiang, Hainan and Heilongjiang. The details of Radio/TV monitoring stations are unknown since official documents on China Radio/TV do not mention such monitoring stations. It has been long believed that jamming was controlled by Army and/or Communist Party. Thus it is quite interesting that jamming is controlled by “underground” organization of SARFT.

（from http://www.worldofradio.com)