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From: bender@oobleck.Eng.Sun.COM (Michael Bender)
Newsgroups: sci.electronics,rec.audio,rec.video
Subject: Re: What is the life-time of magnetic tape?????
Message-ID: <6330@exodus.Eng.Sun.COM>
Date: 20 Jan 91 03:58:02 GMT
References: <1991Jan17.183902.24474@watdragon.waterloo.edu> <1991Jan17.191341.12193@zoo.toronto.edu> <38204@cup.portal.com>
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In article <38204@cup.portal.com> mmm@cup.portal.com (Mark Robert Thorson) writes:
->It seems to me that the "imprinting" phenomenon which slowly destroys
->magnetic tape recordings could be eliminated by winding two tapes onto
->a spool headed for storage: one tape holding the data and a second tape
->with something to diffuse the magnetic field such as nickel metallization.
->Or maybe a fairly thick tape, say 1 mil, would be enough to separate the
->tape layers and prevent imprinting.  Or maybe just winding a blank tape
->onto the same spool would be enough.  Has any of these ideas been tried?

Well, I was reading in an old issue of Videography that they recently found
some "lost" episodes of Fred Astair from the late 50's on COLOR videotape,
which they thought to be the first commercial/broadcast use of color
videotape.  The problem was, they couldn't find the machine that was used to
record the tape; it was a 2" quad, but one that had been extensively modified
by RCA engineers, and was no longer in existance.  The people restoring the
tapes finally got through to some of the RCA engineers that had done the
modifications in the 50's, and via schematics, notes, and circuit simulation
(!) software, were able to, after about 6 months, convert an old Ampex 2"
quad to read the Astair-format tapes.  They said that the tapes were
remarkably well preserved, being kept in a vault and stored properly, and
the images that they got were surprisingly good, considering the era in
which they were recorded.  They transferred the old tapes to D-2 and did a
bunch of clean up and editing in that format.  Pretty neat stuff, huh?  It
would be a bear if everytime you wanted to bring one of your tapes over to
your friend's house for viewing, you had to re-engineer their VCR!!

mike
--
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