Re: [AV Media Matters] Print-through

[smolians@erols.com]

In my experience, stiction often starts at the core rather than the outside
edge.  The method below  described can have serious consequences for tape
where this is the problem.  If it's polyester and one of the product numbers
know to develop this problem, bake first, ask questions later.

Steve Smolian

----- Original Message -----
From: <rohre@ARLUT.UTEXAS.EDU>
To: <AV-Media-Matters@topica.com>
Sent: Monday, July 03, 2000 8:05 PM
Subject: Re: [AV Media Matters] Print-through

>Before I fast wind any older tape, I first hold the reel vertical by the
>hub,
>and wind  off a bit from the reel, looking for layer to layer stiction.
If
>there is ANY, the tape is baked before mounting on a transport.  This is
>also
>a good time to identify if there is edge abrasion of the tape on a flange.
>Precision rewinding on a known good transport at a moderate speed can help
>those tapes that slipped to a flange from improper horizontal storage.
>
>If the tape passes the self stiction test, (gravity pulling off a layer
>easily, from the one underneath), then it is onto the transport for a slow
>speed pull test.  Any squealing, stiction, shudder, or other abnormal tape
>movement and action is again grounds for checking for deposits on the
guides
>and capstan parts, and if indicated, on to the baking cycle.
>
>After baking, very old and shedding tapes from 1972 or about, have played
>even
>at high speed with normal results and NO deposits.
>
>Remember, print through is mainly a voice band artifact, and probably is
not
>a
>problem on other data that does not fall in the range around 1500 or 2000
>Hz.
>What I am saying is that unless you 'hear' print through on playback, I
>would
>not exercise an old tape just for the possible print through it might have
>at
>some point.
>
>Stuart Rohre
>Applied Research Labs Tape Facility, UTX
>
>