Re: [ARSCLIST] Magnetic tape viewers...

["Casey, Michael T" <micasey@xxxxxxxxxxx>]

Graham,

Many thanks for this information. 

The Arnold viewer is very similar to, if not the same as, the 3M
plastiform viewer. Our experience is the same as yours: the sponge in
the container needs to be kept wet, you can't quite see the edges of the
tape, and they work better with tapes containing high recorded levels,
although the tracks are visible enough with some lower level tapes. This
is just one diagnostic tool that we use--our ears, eyes, and the meters
on various types of tape machines are the others. 

I have stayed away from the Kyread developer because I am hesitant to
place any substance on an archival original tape. I'd love to hear
arguments one way or the other about this. From your photos, it looks
like it works quite well.

Mike 


----------
Mike Casey
Associate Director for Recording Services
Archives of Traditional Music
Indiana University

(812)855-8090
 
-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Graham Newton
Sent: Thursday, March 29, 2007 6:22 PM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: [ARSCLIST] Magnetic tape viewers...

Jeffrey Kane jeffkane@xxxxxxxxxxxxxxx wrote:

> The volume pricing is quite a bit more attractive, and shipping via
EMS is
> $20. I rather gathered $130 was over the odds!!! He sent a picture of
the
> results with cassette tape after 30 seconds. The site is mine, no
> popups/spyware... please ignore the other galleries, they're for an
Audiogon
> item I sorely need to list. I'm going to go ahead and order 5 of
these. If
> anyone wants one, please contact me offlist. Price will be cost +
shipping.
> If $20 covers shipping from Japan for all 5, it'll be $203 + shipping
to
> you.
> http://gadgetfreak.us/gallery/main.php?g2_itemId=157

and Mike Casey micasey@xxxxxxxxxxx said:-

> We use the Arnold magnetic viewer which works quite well for this
> purpose. Around $90 from a company in the U.S.


Jeffrey, Mike and all...

A word of warning about these magnetic viewers:

Some years ago I purchased a 3M Plastiform viewer from a 3M distributor,
which
is still available (not from 3M) and has been discussed here.

They all have the same problem... the viewer must be kept in a "humidor"
container with a moistened sponge to keep the device from drying out.
Even in the humidor container, the sponge dries out at an alarming rate
and if
you are not very attentive to it, one day you open the container to find
it has
dried out and has been rendered useless.  You can't fix it... it's now
an
expensive piece of garbage destined for the landfill.

These things work for the purpose, but suffer a few problems.
You can't see the physical edges of the tape so you can't determine if
you have
a tracking problem.  The recorded level on the tape MUST be high or the
viewer
will not display anything useful.

There is an alternate method of viewing which is easy to use, and
reveals the
magnetic track on the tape allowing you to see the tracks relative to
the tape
edge.  It is called KYREAD Magnetic Tape Developer and is a liquid
suspension 
of carbonyl iron which when applied to the tape surface rapidly aligns
itself 
with the magnetic domains and the suspension fluid evaporates leaving a
grayish 
track clearly visible showing everything you need to know about the
track on 
the piece of tape.
Once you have viewed the track, the carbonyl iron is wiped from the tape

surface with a soft cloth or tissue leaving the tape in the same
condition as 
before application of the viewing solution.

Here are two pictures of tape using this method of viewing:-

http://www.audio-restoration.com/tapetrk1.jpg
Standard 1/4 inch 4 tracks showing recording on all four tracks.
The three upper tracks are recorded at normal levels, the bottom track
is low 
level.

http://www.audio-restoration.com/X80trackt.jpg
Tracks from a Mitsubishi X-80 two channel digital recorder.
The bottom track is an analog reference track, the others are all
digital and
the space at the top is another track with no recording on it.


It is supplied in two forms, liquid in a can or bottle which can be used
as a 
dip, or applied with an eyedropper, or a small spray can which is
eminently 
more easy to use.

The can and bottle versions have a habit of drying out very rapidly if
they are
not kept VERY tightly sealed, but the spray can does not suffer this
problem.

Available from:

Kyros Corporation
P.O. Box 628096
Middleton Wisconsin 53562
Tel:  608-238-3587





... Graham Newton

-- 
Audio Restoration by Graham Newton, http://www.audio-restoration.com
World class professional services applied to tape or phonograph records
for
consumers and re-releases, featuring CEDAR's CAMBRIDGE processes.