Re: [AV Media Matters] Digitizing Audio and Video

[Doug Pomeroy <pomeroyaudio@att.net>]

Same applies to audio tapes, contrary to 
what we have been saying for years.

Doug Pomeroy   pomeroyaudio@att.net
Audio Restoration & Remastering Services
----------
>From: Jim Wheeler <Jimwheeler@aol.com>
>To: AV Media Matters <AV-Media-Matters@topica.com>
>Subject: Re: [AV Media Matters] Digitizing Audio and Video
>Date: Fri, May 30, 2003, 2:15 AM
>

> John
>
> By "cycling" I assume that you mean rewinding the tape every few
years.
>
> That originated in a 1958 report by GKI.  It does not apply to
> backcoated
> tapes, which were introduced in the late 1960s.
>
> In 1978-79, Ampex was contracted by the U.S. Air Force to update the
GKI
>
> report.  In 1981, I was asked by SMPTE to summarize the data from the
> U.S. Air
> Force report.  This resulted in the article that I wrote for the SMPTE
> Journal.
> It was in the June 1983 Journal and was titled "Long-Term Storage of
> Videotape".  That article catapulted me into the limelight of the
world
> moving image
> archival community.
>
> In the SMPTE article, I quoted the Ampex study that said that tapes
> stored at
> 70 F should be rewound about every two years.  At least this was
better
> than
> the six month figure from the GKI report.
>
> Since I wrote the SMPTE article, I have given a lot of thought to tape
> rewind
> intervals.  The obvious question is "why rewind?"  The reason is to
> minimize
> distortions in the tape pack.  The next question is "Why do tape pack
> distortions occur?"  The answer is because of changes in pack
> temperature during
> storage and because of incorrect tape wind tensions just before
storage.
>
> If a tape is wound at 65-70 F, at the correct tension, and stored
around
> 65
> F, then tape pack distortion should not occur and rewinding is NOT
> necessary.
> Even if you do find a tape with pack distortion, the tape can be
> returned to
> normal by a couple of high-speed winds.
>
> In summary, wind the tape before storage and store the tape at a
> consistent
> temperature.
>
> Several of us on this Listserve agree that winding tapes every few
years
> is
> more likely to damage the tapes.  Let them set on the shelf and age
> naturally--or is that organically?
>
> BEST
>
> Jim Wheeler
>
>
>
> 

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