28 May
2012
28 May
'12
1:56 p.m.
On 05/28/2012 04:14 PM, Al Kossow wrote:
On 5/28/12 1:01 PM, Mike Loewen wrote:
The worst was 3M blackwatch, It was a dark black rather than the
brown-beige
of the more common binders and it was know 25 years ago for moisture
shedding.
the usual solution was to bake the tape carefully at about 120-130F for
days to
dry it out and do a one pass transcribe. Reason for one pass is that
was likely
all you'd get if lucky.
It was the bane of the audio recording industry for 8 track masters
going south.
That same binder was used for floppies, and other reel to reel tapes
with long term issues.
In that era there were only a few major makers of magnetic tape web
(unslit,
or unpunched sheets of prepared magnetic media). So it was common to see
the same problem in many paces or the lack of a given problem depending
on the main producers.
DEC used several vendors over the years, as did many other based on
availability
and the formulation needed.
Allison
Does this also happen to 9-track tapes? Any
particular vintage or
brands?
Absolutely. I've dealt with thousands of them.
http://bitsavers.org/oven.jpg (on the right) was the oven setup
http://bitsavers.org/tapes.jpg was the reading station
until I lost my CHM lab space
Worst
80's Memorex
BASF
DEC-labeled
Sun-labeled
Better
IBM-labeled
Graham Magnetics
HP-labeled (may be Graham)
3M
Most tape (even the 3M) is now showing water absorbsion in the binder so
it's not really that safe to try any reading without evaluating how
sticky it is.
