Digitising U-matic tape: Diagnosing & Treatment

We have recently completed a job for Quarry Faces, the Mendip Hills Community Heritage Project which has been funded by the Heritage Lottery Fund. Quarry Faces gave us 20 U-matic video tapes that were commissioned for a corporate video in the 1980s.

The Quarry Faces project aims to tell the industry’s story, produce teaching materials for both educational purposes and general interest, and create an archive to preserve images and memories of quarrying over time.

This video we digitised was shot by Coloroll Films of Kilmarnock in 1985, and was delivered to us on U-matic tape. It features a giant walking crusher at Foster Yeoman’s Merehead Quarry (Torr Works).

Walking Crusher at Foster Yeoman Ltd’s Torr Works in 1985 from Quarry Faces on Vimeo.

The video tapes we were sent were high band recordings, rather low band and of very good quality. One AMPEX U-matic tape however was problematic as the tape shell / mechanism had degraded over time and needed careful hand rewinding and reshelling in a known good and newer cassette shell.

When faced with damaged tape, often people automatically assume it needs dehydrating, a process that forces the moisture out of the tape through stable, precise, low temperature baking. However if this is not what is wrong with the tape, dehydrating or ‘baking‘ as it is more commonly called, may in fact damage the tape. If you bake acetate tape that was commonly used in the 1950s and 1960s for example, it would be destroy it.

An oven used for baking tape

Ampex filed for a patent for the correct temperature to recover Ampex tapes. The patent referred to “a typical temperature used is 54’C. and a typical effective time is 16 hours”.

The simple truth is, there is no all encompassing answer to know what happens to tape when it degrades, or when the cassette shell mechanism malfunctions, and each tape that is sent to us is of course individual. Digitisation and the art of restoring old tape is a relatively new area, and no one has yet made a machine that is able to precisely diagnose what is wrong with each individual tape when problems occur. Is the tape suffering from sticky shed syndrome or binder hydrolysis, or is it ‘vinegar syndrome’, a condition which afflicts acetate tape? Only through careful diagnostic work, which at Greatbear includes using our range of in-house test tapes, can the correct remedy be found.

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