Drop-out compensator

A drop-out compensator is an error concealment device that was commonly used in the analog video era to hide brief RF signal "drop-outs" on videotape playback caused by imperfections in or damage to the tape's magnetic coating. Most compensators worked by repeating earlier video scan-lines over short periods of signal loss; one early such system, "Mincom" was developed in the 1960s by the Minnesota Mining and Manufacturing Company, the company now known as 3M. Because of the high cost of the 3M device at the time, BBC R&D engineers developed a simpler, less expensive unit based on a sample-and-hold technique for in-house use.