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RE: arsclist Identifying Tape Types
I should like to contribute a European answer to this question.
The leading manufacturers of professional tape in Europe nearly always
printed the tape type on the back of the tape, and this was only omitted in
the specific cases I shall mention below. This applies to KODAK, AGFA and
BASF, whose names appear together with the tape types. It was also an
unwritten rule at BASF that the *colour* on the backing also indicated the
tape type; thus Type LR56 was always either a yellowish green or a greenish
yellow! (depending what light you illuminated it with!)
Of course, this doesn't answer the question posed by Nathan Georgitis at
all; so I shall now answer the question from a strictly British viewpoint.
Here in Britain, virtually all amateur tape was unlabelled. I can't be
certain of my next remark; but because Purchase Tax did not apply to
professional tape, the existence of printing or the use of specific colours
was accepted by tax collectors as differentiating between "professional" and
"amateur" tapes. (Similar labelling was sometimes applied to commercial disc
records as well).
The principal professional consumer of tape was the British Broadcasting
Corporation. Because in general they supported several manufacturers to
avoid a monopoly situation, and because signal volumes on the tapes
increased over the years, the tapes they used were standardised using
different colours to indicate the magnetic characteristics of the tape (so
an old tape would not undermodulate the transmitters).
The first, a formulation known as "H50", was light brown, and the
backing was the same, so the only way you could tell the oxide from the
backing was that the latter was glossy.
The second ("H77") was the same colour, but had +8dB more sensitivity.
(It was introduced in 1956, but in Britain it seems to have been quite
normal for four or five years to elapse between the dates of manufacture and
of purchase). In the case of EMI tape, both sides were still the same
colour; but the word "EMITAPE" is always printed on the backing to
distinguish it from H50. ("EMITAPE 4" was "standard-play," 1.5 thou
thickness, and "EMITAPE 5" was "long-play", 1.0 thou thickness, used on
portable machines). To be pedantic, both H50 and H77 used PVC plastic, not
polyester; the difference is that when the end flaps out by centrifugal
force on an unbraked spooling motor, PVC separates into some dozens of
longitudinal strips resembling a paintbrush, while polyester doesn't - it is
homogenous, and stretches rather than splits.
The earliest Zonal tape was also made to the H77 specification, also
with a light brown oxide; but the backing was always coloured, usually by
applying dark green (sometimes dark blue) on top of the basic light brown
plastic. Kodak I've already mentioned; I have never seen anything but
PVC-based Kodak tape here in Britain. (It was made in France).
The next upgrade was to something called "Type 100" formulation; I don't
know the exact date, but approximately 1968. This could hold another +4dB of
signal-level. This is always a much darker brown, with no printing. I
hesitate to make my next remark (knowing that American chocolate is nothing
like European chocolate); but whereas H77 was "milk chocolate" coloured,
Type 100 was "plain chocolate". EMItape 815 is the same magnetic
formulation, but has a matt back (which was beginning to be demanded by
professionals); BBC Type 100 always had a glossy back.
In an attempt to upgrade this in the late 1970s, the BBC tried using
Scotch 262 manufactured in Italy; this always had a matt light grey backing
and near-black oxide. It stimulated development of the British "Type 200"
formulation, with another 4dB of headroom. This always had very dark (nearly
black) oxide, and a *matt* black backing - the *oxide* side is the glossier
one! Again, this was supplied by many manufacturers (with identical results
as far as I know); Agfa printed the type-number on their version, type 464 I
think it was; and the BASF equivalent was - and still is - Type SM468. The
Scottish factory of Zonal was making this (known by them as Zonal 675) when
it closed a couple of years ago.
Here endeth the story of British professional audio tape.
From: Nathan Georgitis [mailto:nathan_georgitis@xxxxxxxxxxx]
Sent: 17 July 2001 22:35
Subject: arsclist Identifying Tape Types
I am in the process of creating an inventory of a large collection of open
reel recordings on 1/4-inch, polyester-base magnetic tape. These reels date
from 1970 to 1990. Few of the reels are housed in their original boxes. None
of the tapes seem to have identifying tags at the head or tail.
I would like to identify the brands and numbers of these tapes, if possible.
I have been noting the presence or absence of backcoating and trying to
develop a feel for tape thickness and an eye for the colors of oxide
formulations. Does anyone have any tips for identifying tapes beyond these
steps? Is there any collected information out there on tape types and their
characteristics, such as thickness, reference fluxivity, years of
Thanks in advance for any help.
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