30 Apr
2017
30 Apr
'17
7:38 a.m.
Looking for recommendations for a bulk tape eraser for SDLT and DLT IV
tapes.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
30 Apr
30 Apr
8:33 a.m.
I'd go to the Athana site, they have some degaussers and a nice write-up
about what can (and can't) be safely degaussed
2017-04-30 11:38 GMT-03:00 Mike Loewen via cctalk <cctalk at classiccmp.org>:
Looking for recommendations for a bulk tape eraser for SDLT and DLT IV
tapes.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
8:53 a.m.
On 04/30/2017 07:38 AM, Mike Loewen via cctalk wrote:
Looking for recommendations for a bulk tape eraser for SDLT and DLT
IV tapes.
If it's just a small quantity to be erased, there are many Radio Shack
videotape erasers being offered, some NIB, all for about $20. I've used
one for years on floppies and tapes. It's not for erasing piles of
tapes, as there's a thermal overload protector on it, limiting the
amount of time that you can use it.
--Chuck
6:22 p.m.
Chuck Guzis via cctalk wrote:
On 04/30/2017
07:38 AM, Mike Loewen via cctalk wrote:
Looking for recommendations for a bulk tape eraser
for SDLT and DLT
IV tapes.
If it's just a small quantity to be erased, there are many Radio Shack
videotape erasers being offered, some NIB, all for about $20. I've used
one for years on floppies and tapes. It's not for erasing piles of
tapes, as there's a thermal overload protector on it, limiting the
amount of time that you can use it.
--Chuck
7:06 p.m.
On 04/30/2017 06:22 PM, Jerome H. Fine via cctalk wrote:
> Chuck Guzis via cctalk wrote:
FORTUNATELY, I had an old voice coil fram a speaker
available. It
must have been a large speaker because the coil was a cylinder about
3" in diameter and about 3" long. The permanent magnet seems to have
a few pounds of pull on any iron object, so I thought it might be
useful. It probably takes about 30 seconds of slowly rotating the
voice coil over the surface of the TK50 / TK70 tape to sufficiently
BULK erase the tape such that the TK70 drive would write on the tape.
Since I believe that the TK50 / TK70 tapes are early DLT tapes, this
method may also be successful, if a bit slow, for a small quantity of
tapes.
I've entertained the idea of pulling out one of my old microwave oven
transformers, cutting off the "I" sections, so that it's only "E"
laminations, and then removing the high-voltage outer windings (easy
enough to do with a Dremel--some folks re-purpose these boat anchors to
serve as the basis for spot welders and such.
Carefully limiting the current with a large incandescent lamp, that
should give one a whopping AC field that should take the magnetization
out of anything.
But...it feels like too much work for an old man.
--Chuck
7:10 p.m.
On 4/30/2017 6:22 PM, Jerome H. Fine via cctalk wrote:
> Looking for recommendations for a bulk tape eraser for SDLT and DLT
> IV tapes.
Eons ago at Microdata we had a commercial grade bulk eraser which
could
do 2400' reels maybe a bit larger.
I wondered by one day with a new fangled device, a 16k eprom. while a
small chat developed by the table where
the eraser was, I casually put the eprom on the eraser, and turned it
on, just because.
one of my otherwise smart colleagues looked with a concerned look on his
face and then queried whether that
would work with the eproms.
don't know that he ever lived that one down.
Wish I had it, I'd certainly pass it along.
thanks
jim
8:55 a.m.
You may as well run them through a shredder. All modern tapes have embedded servo tracks.
On 4/30/17 7:38 AM, Mike Loewen via cctalk wrote:
Looking for recommendations for a bulk tape eraser for SDLT and DLT IV tapes.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
10:04 a.m.
On 04/30/2017 08:55 AM, Al Kossow via cctalk wrote:
You may as well run them through a shredder. All
modern tapes have
embedded servo tracks.
Certainly not DLT IV tapes--I've done the bulk eraser thing with them
and the result re-recorded just fine.
But then, DLT IV is hardly modern.
--Chuck
10:55 a.m.
On Apr 30, 2017, at 10:04 AM, Chuck Guzis via cctalk <cctalk at classiccmp.org>
wrote:
On 04/30/2017 08:55 AM, Al Kossow via cctalk wrote:
I know you can?t run LTO tapes through one, but if I remember correctly you can do at
least the original SDLT tapes. We had a heavy duty degausser in the datacenter, up until
a couple years ago. The tape library vendor we were using at the time wanted us to
degauss tapes prior to reusing them due to all the issues we were having. That meant
degaussing 100?s of tapes a week. Normally contractors would do it, but in an emergency,
I?d do it at times. With the later tapes, you had to run them through something like 4
different ways, otherwise they were still readable (which is why I?m pretty sure we were
degaussing SDLT tapes). As I recall, DLT IV tapes only had to go through once.
Zane
You may as well run them through a shredder. All
modern tapes have
embedded servo tracks.
Certainly not DLT IV tapes--I've done the bulk eraser thing with them
and the result re-recorded just fine.
But then, DLT IV is hardly modern.
--Chuck
9:05 a.m.
I'll add that using the little Radio Shack "high power" device well, is
not a simple matter--the trick is to keep the eraser moving and using
different angles and distances.
If you want a high-power tape *degausser*, be prepared to part with some
real cash--the low end seems to start just north of $1000. Many even
claim to be able to do hard drives.
--chuck
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