You might be hearing the Chinese jammer that is usually on top of SOH. Unless you speak Chinese & heard an ID (I think SOH sometimes ID's in English). The jammers are thought to be 500 kw whereas SOH is 0.1 kw (100 watts). I 've only heard SOH one time & always catch the CNR jammer. Firedrake is mostly used to jam Radio Free Asia but CNR is used there too. Chinese jammers often have as many as three different signals jamming one station firedrake, CNR1 & noise jammers.