Radio Thailand is a public radio station of Thailand. National Broadcasting Service of Thailand operates this. Radio Thailand World Service (RTWS) is the international service of NBT. Radio Thailand started its journey on 28 October 1938. It was under call sign HSK9. Radio Thailand is still using this call sign on its broadcast. HSK9 B17 schedule of Radio Thailand World Service shows it’s replaced 15590 kHz by 13745 kHz.