Editing NICAM (section)

===VCR===
{{main|Videocassette recorder}}
[[VHS]] and [[Betamax]] home [[videocassette recorder]]s (VCRs) initially only recorded the audio tracks by means of a fixed linear recording head, which was inadequate for recording NICAM audio; this significantly limited their sound quality. Many VCRs later included high quality stereo audio recording as an additional feature, in which the incoming high quality stereo audio source (typically [[FM radio]] or NICAM TV) was [[frequency modulation|frequency modulated]] and then recorded, in addition to the usual audio and video VCR tracks, using the same [[Bandwidth (signal processing)|high-bandwidth]] [[helical scan]]ning technique used for the video signal. Full-size VCRs already made full use of the tape, so the high quality audio signal was recorded diagonally ''under'' the video signal, using additional [[helical scan]] heads and [[depth multiplexing]]. The mono audio track (and on some machines, a non-NICAM, non-Hi-Fi stereo track) was also recorded on the linear track, as before, to ensure backwards-compatibility of recordings made on Hi-Fi machines when played on non-Hi-Fi VCRs.

Such devices were often described as "HiFi audio", "Audio FM" / "AFM" (FM standing for "Frequency Modulation") and sometimes informally as "Nicam" VCRs (due to their use in recording the Nicam broadcast audio signal). They remained compatible with non-HiFi VCR players since the standard audio track was also recorded, and were at times used as an alternative to [[audio cassette tape]]s due to their superior frequency range and flat [[frequency response]].