This paper is a report on the design and implementation of the Video Recovery Project, a project jointly sponsored by the Public Archives of Nova Scotia, The Vajradhatu Archives, and the Naropa Institute of Boulder, Colorado. This is a project to transfer open-reel 1/2" video tape, most of which was recorded in the 1970's, to modern video formats.
A main problem in transferring early video is the head clog produced by dirt and loose oxide on the tapes. A vaccuum cleaning system was constructed to deal with this problem. A piece of perforated foil from a Braun shaver head was glued onto the front of the erase head of a 1/2 inch video playback machine, after the internal parts of the head were removed. The shaver head was chosen because the perforations in the head are created by a laser and thus have no burrs that might damage the tapes. A plastic tube running to a vaccuum source was then attached to the back of the head.
Initially, it was thought that it would be necessary to sacrifice the playback machine to become a cleaning transport. However, before removing the video heads, a test was performed to determine if the tape would play back while being vaccuum cleaned. In fact, it was determined that the vacuum not only cleaned the tapes but also appeared to stabilize the tape from mechanical vibration of the old reels. Therefore, the cleaning and the transfer of the tapes could be done simultaneously, using one machine.
Another technical feature of the transfer process is that the video signal is run through a time base corrector to further stabilize the electronic image. The particular TBC being employed has built into it an automatic dropout compensator which, unlike other existing dropout compensators, does not require RF output from the video head. The old black and white playback machines do not generate this signal, so other dropout compensators cannot be used.
Overall, there appears to be less danger of damaging the original tapes using the vaccuum cleaning method than with the use of other methods previously employed, which involve cleaning the tapes with a razor or with a cloth.
Continue on and read the technical paper in full.