Sky originally launched on 18 May 1990 as an analogue UHF service. Subscribers required a VideoCrypt decoder and a UHF aerial, both of which were supplied by when joining Sky. The signal was sent with the picture scrambled using VideoCrypt technology; the decoder was used to unscramble the picture. Sky Movies was the only channel broadcast in NICAM stereo; Sky Sport and Sky News were broadcast in mono. The original decoder didn't actually support stereo sound; if a subscriber wanted to watch Sky Movies in stereo, the subscriber had to feed the audio from another source such as a NICAM stereo capable VCR.