[Info-vax] DLT Tape degaussing services

[Richard B. Gilbert]

Rich Jordan wrote:
> On Mar 19, 2:02 pm, "John Smith \(not the one @ HP\)"
> <a... at nonymous.com> wrote:
>> "David Mathog" <mat... at caltech.edu> wrote in message
>>
>> news:gpopc4$8gi$1 at naig.caltech.edu...
>>
>>>> I'm certainly
>>>> willing to try a smaller unit (missed one on ebay yesterday that was
>>>> for reel to reel audio tapes) but expect it won't be overly
>>>> effective.  So far no luck at locating a nearby service.
>>> See what's available at the local Universities and research labs.  NMR
>>> machines and cyclotrons have enormous magnets.  How far are you from Fermi
>>> lab?
>>> Regards,
>>> David Mathog
>> How about the nearest Navy Yard when they degauss their ships? Put the tapes
>> in plastic bags and hang them over the side as the ship is degaussed. Ought
>> to work.
> 
> Heh.  Unfortunately I doubt the Navy does anything like that here in
> Ill Annoy.  I actually did look around to see if there was a wrecking
> yard that used a crane with an electromagnet but couldn't find one
> (and if I did I doubt they'd be willing, but who knows).
> 
> I knew someone at Fermi but he left.  Without that contact I'd hate to
> bother them for something like this.  Fun thought though...
> 
> Maybe I should build a railgun... if it didn't erase them it could
> launch them pretty hard; more fun than a sledgehammer for data
> destruction.
> 
> I did some more digging and there seems to be a breakpoint at about
> 3500-3700 Gauss where the sellers start claiming the ability to erase
> DLT cartridges (and around 4350 Gauss for SDLT-2 and higher.  I read
> reports that the Radio Shack high power unit was not able to do the
> job on DLTTape IV 20GB cartridges (ironically the same situation;
> someone trying to make tapes used on a real DLT drive usable on a
> VS80).
> 
> Found one service that may end up costing about $4.00/cartridge by the
> time shipping there and back is considered, and nothing local so far.
> I can get new tapes on Ebay for very close to that price... I think
> we're going to end up doing the crush kill destroy thing on the
> tapes.  A shame, but its not worth the time and effort to get them
> wiped.
> 
> Rich

Is there some reason you can't simply INIT the tapes and reuse them?