Flying-erase heads are special electro-magnetic elements mounted on the video disk ahead of the record/playback heads. They perform a similar function as the stationary full erase head (that always comes on during normal recording) except they erase each individual scan. They clear the tape of the old video signal ahead of the recording head to prepare it to receive a new recording. If the old scan is not fully removed it will show up in the new recording as a color noise band called the moiré effect or rainbow noise. Remnants of the old recording would still be there, trying to play along with the new one. This happens because the full erase head didn't remove all the old recording because it is located just before the video drum and before the spinning heads. When a recording is terminated, there is always some recording information left over in the area before the full erase head clears it away. This usually isn't an issue during normal recording, but when performing an edit it needs to be clean, and free of any leftover artifacts. If you are doing a video insert, you want the trailing video signal to be undisturbed by the full erase head. So for this function the full erase head is turned off and the special set of rotating flying-erase heads are used. The result is the inserted video that is clean on both ends. Found only on higher-end Betas these are mounted just in front of the video heads on the video disk. They spin with the heads and erase the video a single scan at a time. They turn off when the insert is terminated. The result is the insert starts at the edit point and then ends without disturbing the video that comes after it. Most recorders with flying erase heads also turn them on during normal recording to further ensure a clear area before the recording heads lay down their magnetic signal. ©Misterßetamax go to homepage