Duke Libraries has a large collection of analog videotapes, in several different formats. One of the most common in our archives is 3/4″ videotape, also called “U-matic” (shown above). Invented by Sony in 1969, U-matic was the first videotape to be housed inside a plastic cassette for portability. Before U-matic, videotape was recorded on very large reels in the 2″ format known as Quadruplex which required heavy recording and playback machines the size of household refrigerators. U-matic got its name from the shape of the tape path as it wraps around the video head drum, which looks like the letter U.
The format was officially released in 1971, and soon became popular with television stations, when the portable Sony VO-3800 video deck was released in 1974. The VO-3800 enabled TV crews to record directly to U-matic videotape at breaking news events, which previously had to be shot with 16mm film. The news content was now immediately available for broadcast, as opposed to film, which had to wait for processing in a darkroom. And the compact videocassettes could easily and quickly be transported to the TV station.
In the 1970’s, movie studios also used U-matic tapes to easily transport filmed scenes or “dailies,” such as the first rough cut of “Apocalypse Now.” In 1976, the high-band BVU (Broadcast Video U-matic) version of 3/4″ videotape, with better color reproduction and lower noise levels, replaced the previous “lo-band” version.
The U-matic format remained popular at TV stations throughout the 1980’s, but was soon replaced by Sony’s 1/2″ Betacam SP format. The BVU-900 series was the last U-matic product line made by Sony, and Duke Libraries’ Digital Production Center uses two BVU-950s for NTSC tapes, as well as a VO-9800P for tapes in PAL format. A U-matic videotape player in good working order is now an obsolete collector’s item, so they can be hard to find, and expensive to purchase.
Unfortunately, most U-matic tapes have not aged well. After decades in storage, many of the videotapes in our collection now have sticky-shed syndrome, a condition in which the oxide that holds the visual content is literally flaking off the polyester tape base, and is moist and gummy in texture. When a videotape has sticky-shed, not only will it not play correctly, the residue can also clog up the tape heads in the U-matic playback deck, then transfer the contaminant to other tapes played afterwards in the same deck.
To combat this, we always bake (dehumidify) our U-matic videotapes in a scientific oven at 52 celsius (125 fahrenheit) for at least 10 hours. Then we run each tape through a specialized tape-cleaning machine, which fast-forwards and rewinds each tape, while using a burnishing blade to wipe off any built-up residue. We also clean the video heads inside our U-matic decks before each playback, using denatured alcohol.
Most of the time, these procedures make the U-matic tape playable, and we are able to digitize them, which rescues the content from the videotapes, before the magnetic tape ages and degrades any further. While the U-matic tapes are nearing the end of their life-span, the digital surrogates will potentially last for centuries to come, and will be accessible online through our Duke Digital Repository, from anywhere in the world.