Hi Marie,

If you measure the hub diameter and the thickness of the pack, I can
compute the tape thickness.  You'll need to measure as accurately as
possible.  I measure to the nearest 0.005" (0.3 mm) to get very good
results (I use digital calipers).  I'll assume that the tape is 500 M
in length.  If you have a really accurate thickness gauge, you can
always measure a pack of 10 tape layers directly.  The overall
thickness will at least help eliminate a few candidate brands/models
of tape.

Could you tell us more about the tape, like color of the oxide?  If
you have handled the tape, does it "feel" like a 1-mil or 1.5-mil base?
Presumably no back-coating?  Color of the base tape?

I'm wondering if AT-220 is "Ampex Tape" model 220.  Maybe they
purchased bulk tape from Ampex and spooled and packaged it in
China.  If you lurk on the Ampex Listserv, one of the Ampex old-timers
might be able to tell you if they distributed bulk tape to China.

Maybe the reel itself could provide a clue?  Does the reel have any
markings?  Maybe there's a hint from the shape of the reel flange
holes or hub diameter?  Is it a slotted hub?

Last but not least, maybe a post to this list for native Chinese
readers might help you locate someone who can translate the characters
if you have a scan of the box.

Eric Jacobs

The Audio Archive, Inc.
tel: 408.221.2128
fax: 408.549.9867
mailto:[log in to unmask]
Disc and Tape Audio Transfer Services and Preservation Consulting

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]]On Behalf Of Marie O'Connell
Sent: Wednesday, February 11, 2009 10:23 AM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Magnetic tape brand

Hi Jeff

It is 1/4" inch, polyester, and actually looks as if it has never been used
as it is only a pancake still in its plastic bag inside the pale blue box.
The tape measures 9 inches in diameter.  I don't think it is that new, I
would say it is possibly 20 odd years old.  It has 7 chinese symbols above
the AT-220 with the 500 M written under that.  Also written on the box is
Stereo Magnetic Tape (in English) and Made in China (in English).  There is
a doodle of a baby's face on the back of the box done in biro!!  If there is
no audio on it then the doodle, if drawn by the donor, could be the most
important part!

I know nothing about the chinese language and just jumped in with a totally
uneducated guess, EMITAPE, only due to the 7 symbols '-)
On Thu, Feb 12, 2009 at 4:42 AM, Jeff Willens <[log in to unmask]> wrote:

> Marie,
> Anything else you can tell us about the tape? Acetate/Polyester? Is it a
> fairly new reel?
> -Jeff Willens
> Audio Restoration Engineer
> VidiPax
> [log in to unmask]
> -----Original Message-----
> From: Marie O'Connell [mailto:[log in to unmask]]
> Sent: Tuesday, February 10, 2009 7:55 PM
> Subject: Magnetic tape brand
> I was hoping to get some advice regarding a tape I am presently
> accessioning.  It is made in China, is a pancake only which measures 9
> inches across, and on the box it says - Stereo Magnetic Tape, AT-220 500
> Unfortunately the brand name itself is in Chinese, I presume.  Any ideas?
>  I
> tried googling AT-220 but no luck.
> Cheers
> Marie