Hi Shai,
Given that there seems such a lack of evidence for squealing on this
177 tape type I wonder if there is another factor at work. I know you
said the tapes had been stored well but is it possible at some stage a
substance contaminated them, perhaps something in the atmosphere in
which they were stored. I know from Specs Bros that in disaster
recovery where certain residues are on the tape's surface, attempts
are sometimes made to clean the residues off. If there is a section
of tape that is blank, the tape could be suitably cleaned and dried,
and then played to test for squealing. Working with a blank tape
sample would mean there is no program at risk and possibly a
solution to the squealing problem found.
Cheers Tim.
----- Original Message -----
From: "Association for Recorded Sound Discussion List"
<[log in to unmask]>
To:<[log in to unmask]>
Cc:
Sent:Tue, 24 Nov 2020 08:32:45 +0200
Subject:Re: [ARSCLIST] Scotch AV177 sqealing
I should note that in the 43 years of dealing with 176 I have never
had one
squeal. I’m surprised to learn that some batches squeal. Luckily
they
haven’t made it to Israel.
One last note, the 3 reels of 177 that squeal have been stored in a
proper
vault.
Cheers
Shai
On Mon, 23 Nov 2020 at 23:08 Richard L. Hess
<[log in to unmask]>
wrote:
> Hi, Corey,
>
> Thanks for the concern over my time...I do have other things to do,
but,
> for now, I seem to be the only one doing this.
>
> In fact, I just updated this page based on Dennis's comment and
wove it
> in with a larger analysis of the 3M spreadsheet of tape types. The
> 3M175+ and 3M 176+ sections under Soft Binder Syndrome have been
> updated, Note that 201+ also appears in the light edge shedding
section.
>
> <
>
https://richardhess.com/notes/formats/magnetic-media/magnetic-tapes/analog-audio/degrading-tapes/
> >
>
> There was a good deal of energy generated for just such a database
> following the AES Archiving conference at the Library of Congress
in
> Culpeper, VA, in 2018.
>
> Following that, some people who said they'd share datasets did not
do so
> with no explanation.
>
> Also, Dr. Federica Bressan and I spent hours discussing this issue
and
> have come to the conclusion that not enough accurate raw data are
> available at this point to legitimately construct such a database.
>
> We have ample anecdotal evidence of significant batch variations in
many
> manufacturers' tapes. Since the vast majority of recordings do not
have
> the tape batch number recorded with it, many do not have traceable
> documentation of the published tape type, the tape type may have
changed
> over time,(one U-Matic tape type had four different FTIR signatures
over
> time and there we're pretty certain that the type number is on the
> cassette (Benoit Thiebaut, Prestospace Project c. 2006)), and there
is
> usually little to no record of the storage conditions for the tape.
>
> So, it is very difficult, if not impossible, to make an accurate
> database that goes beyond the type of general narrative that I've
been
> providing. While I think we'd all love to have a database that
says,
> "Use this technique to remediate tape type X."
>
> Rather than a documentation approach, I have been pushing for a
> "pool-test-kit" type of system where applying drops of something or
> other to a small sample of the tape would suggest what to do.
>
> Andrew Davis of the Library of Congress has suggested a water
droplet
> test which I have tried and found cumbersome, slow, and subject to
> interpretation...and this was only to say, "does the tape need
baking."
> It seemed promising until I tried it, but maybe he's onto
something.
>
> I would be curious if anyone has any further ideas on this, I don't
want
> to throw a bucket of ice water on the idea, but it is fraught with
> difficulties.
>
> Thanks!
>
> Cheers,
>
> Richard
>
>
>
> On 2020-11-23 1:06 p.m., Corey Bailey wrote:
> > As Dennis Rooney pointed out: "3M 176 and 177 both can squeal."
> >
> > Shai's post points out the need for a centralized database
because this
> > list is sprinkled with a wealth of valuable information on many
subjects.
> >
> > Richard Hess maintains a page on audio tape known to have
problems but
> > he should not have to keep up a centralized database (He has
other
> > things to do, I'm sure).
> >
> > Anyone know of some good email mining software?
> >
> > My $0.02,
> >
> > CB
> >
>
> --
> Richard L. Hess email: [log in to unmask]
> Aurora, Ontario, Canada 647 479 2800
> http://www.richardhess.com/tape/contact.htm
> Track Format - Speed - Equalization - Azimuth - Noise Reduction
> Quality tape transfers -- even from hard-to-play tapes.
>
--
Cheers
Shai Drori
Expert digitization services for Audio Video
3K scanning for film 8mm-35mm
Timeless Recordings Music Label
www.audiovideofilm.com
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