A planned opening date of 1 April 1966 had to be abandoned when the station's vessel, "Oceaan 7", shed its radio mast. However, the station finally opened in June, broadcasting on 1115 kilohertz, 269 metres, in the medium wave. This wavelength was used by some existing radio stations in southern and eastern Europe but these were too far away for Radio 270 to cause them any trouble. However, the frequency was close to Radio London on 1133 kHz, resulting in the potential for mutual interference on radios with less precise tuning.