Re: [ARSCLIST] Risk assessment tool Q2

["Richard L. Hess" <ArcLists@xxxxxxxxxxxxxxx>]

At 02:14 PM 1/5/2006, Casey, Michael T wrote:
> Hi,
>
> The second set of questions that I am looking for help with relate to
> audio cassettes.
>
> 1. What problems are encountered in transferring cassettes? How does
> deterioration manifest with cassettes?

Mechanical problems are #1 when there are problems.

The Nakamichi machines that generate their own tension and push the 
pressure pad out of the way solve many of the problems.

The other major problem appears to be loss-of-lubricant which 
manifests itself by a squeal that is only repairable by adding 
lubrication. Baking does not appear to help and may exacerbate the problem.

> 2. Does the audio signal on a cassette deteriorate in any way over time?
> [I have heard it suggested, for example, that the signal to noise ratio
> gets comparatively worse over time on a cassette (compared to open reel)
> but have not seen any data]

What is the proposed mechanism for this deterioration. There is 
structurally no major difference between cassette tapes and reel 
tapes in this regard. Thinner base film and narrower tracks may be 
possible causes, but what is the real mechanism? I have seen this on 
one or two cassettes, but had always assumed they were stored in the 
magnet drawer from the way they behaved.

> 3. Do Type IV (metal) tapes exhibit any problems not found on other
> types? Do chromium dioxide tapes deteriorate faster than ferric oxide?
> [this has been suggested by one report]

There were early reports of corrosion of early metal videotapes. I 
see a mix of Cr02 and ferric oxide tapes and don't see one as worse 
than the other. The Princess Diana tapes were recorded on a mix, and 
the Cr02 tapes were worse, but it appeared that the recording 
machine's tape settings were incorrect rather than anything else.


> 4. Have you noticed any brand-related problems?

Sony has been subject to Loss of Lubricant (LoL) as have 3M dictation 
cassettes, which, I believe, were outsourced.


> 5. Have you noticed any age-related problems?

Not directly attributable.

> 6. Problems with C-120s are well-known. Any similar problems with C-90
> or C-100s?

None that I have seen. In fact, C-120s don't seem to be a major 
challenge for the Dragons.

Richard L. Hess


Richard L. Hess                   richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada       http://www.richardhess.com/
Detailed contact information: http://www.richardhess.com/tape/contact.htm