Assertion: tape recorder's head | /r/CapableOf | remain on their helical tracks
Facets:
Source sentences:
text: Another linear control track, at the tape's lower edge, holds pulses that mark the beginning of every frame of video; these are used to fine-tune the tape speed during playback, so that the high speed rotating heads remained exactly on their helical tracks rather than somewhere between two adjacent tracks (known as "tracking").