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CBC Digital Archives

Television: Video

Videotape lasts longest when it's stored in cool, dry conditions. But even then, it doesn't keep forever. The most common aging problems are dirt build-up and decayed tape oxide that falls off the tape backing. When this occurs, the heads on the player have trouble reading the signal and they will get clogged up. Every tape is run through a cleaning machine before you're able to make a quality copy.

In the normal cleaning cycle, the tape is first wiped free of dirt with a couple of small tissues. Next, it is rubbed up against a small blade that removes any loose magnetic oxide particles. The final step sees the tape passing over a third tissue on the take-up reel. Then the whole process is reversed. None of this should affect the TV show on the tape.

Even tapes in pristine condition may still have video "noise" and other imperfections that reflect their age and the type of equipment from which they were produced. If so, a technician uses a "video noise reducer" that removes imperfections before copying. Colour loss and other imperfections can often be corrected at this time, too.

For tapes with serious oxide decay - it can be literally peeling off - there is another option: the ovens! No, not to burn them, but to warm them. Over the years, people working with old tape have learned that gentle heating - for anywhere from six to 24 or more hours, at temperatures ranging from 35°-65° Celsius - can actually cause the magnetic oxide to re-bond with the tape backing. The tape can then be run through a player and copied - but usually only once. The shock from the heating and re-bonding often renders a tape more fragile, so that it falls apart completely after that one last play. Such an all-or-nothing strategy is only tried when nothing else will work.