 Radio 4 replaced it on 30 September 1967, when the BBC renamed many of its domestic radio stations, in response to the challenge of offshore radio.It moved to long wave in November 1978, taking over the 200 kHz frequency (1500 metres) previously held by Radio 2 - later moved to 198 kHz as a result of international agreements aimed at avoiding interference (all UK MW/LW frequencies are divisible by 9).At this point, Radio 4 became available across all of the UK for the first time and the station officially became known as Radio 4 UK, a title that remained until September 1984.