Degaussing
Well, I checked out some info on Degaussing. It takes alot more power to erase DV tapes than what Hand Held Radio Shack Bulk Tape Erasers can handle. Here's a chart showing the power needed to erase DV Tapes. (It takes 1700 Oersteds to erase DV tapes.) AUDIO Tapes Oersteds
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350 Oersteds = 1/2", 1" and 2" 450 Oersteds = Compact cassette ferric (IEC Type I) 450 Oersteds = Compact cassette chrome (IEC Type II) 680 Oersteds = 1/4", 1/2" digital audio reel 745 Oersteds = 3/4" digital audio cassette 1440 Oersteds = RDAT 930 Oersteds = ADAT 350 Oersteds = Cartridge 10/750 Oersteds = Pancake various 350 Oersteds = Sep.mag.35mm film 700 Oersteds = DCC 365 Oersteds = Voice logging reel 1/2", 1" COMPUTER/Data Tapes Oersteds
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300/700/1500 Oersteds = Floppy diskette 51/4",31/2" 550 Oersteds = PC,Mini, Hard disk 310 Oersteds = Main-frame Spool 1/2" 550/650 Oersteds = Cartridge 1500 Oersteds = TK50 etc. 700 Oersteds = DCRSI cassette 310 Oersteds = Reel 1/2", 1" 675/750 Oersteds = Cassette 1050/1500 Oersteds = 8mm/4mm 1440 Oersteds = DAT-R 550 Oersteds = Cartridge 3480, DC600A 1900 Oersteds = Digital backup cartridge VIDEO Tapes Oersteds
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750 Oersteds = Reel 1"`B'and`C' format 300 Oersteds = 2" 675/750 Oersteds = VHS pancake 2100 Oersteds = Mirror master 675/700 Oersteds = Cassette VHS 710 Oersteds = Beta 1000 Oersteds = SVHS 1050/1500 Oersteds = Hi8 630 Oersteds = U-matic 745 Oersteds = U-matic SP 1700 Oersteds = Beta SP, MII 850 Oersteds = D-1 1700 Oersteds = D-2, D-3 Digital 1700 Oersteds = Digital Betacam, D5 Digital 1700 Oersteds = DV, DVC, DVCAM, DVC PRO SECURITY formats Oersteds
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600 Oersteds = Credit card 600 Oersteds = Library ticket 600/3500 Oersteds = Rail/Air ticket 600 Oersteds = Hotel door lock (INFO FROM: <a href="http://www.weircliffe.co.uk/degaussi.htm">Weircliffe</a>)
Here's something interesting:
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From: Art Munson <artmuns@tape.com> Subject: Degaussing, erasing and magnetism Date: Tue, 27 Aug 1996 11:58:42 -0500 (CDT) Degaussing, Erasing and Magnetism
A lot of folks have asked about degaussing (erasing) media and particularly DAT tapes, so here's some info you might find helpful. Gauss: A unit of measurement of magnetic flux density produced by a magnetic force (coils). Gauss is a measurement of coil strength. Oersted: A unit of magnetic intensity of a magnetic field in a vacuum. Oersted is a measurement applied to media. A 4mm DAT tape has a magnetic field strength of approximately 1500 oersteds.
Coercivity: The amount of applied magnetic field (of opposite polarity) required to reduce magnetic induction to zero. The ease or difficulty by which magnetic media can be de-magnetized. A 4mm DAT tape is a high coercivity tape. So: 1.) The higher the oersted rating, the more energy needed to *properly* demagnetize it. 2.) In order to degauss (erase) a magnetic tape, a magnetic force (gauss) of 2 2/3 to 5 times greater than that of the media to be degaussed must be created. In other words to demagnetize a media of a given oersted rating, it will take 2 2/3 to 5 times the amount of energy. 3.) A 1500 oersted tape would need a magnetic field strength in the neighborhood of at least 3000 gauss in order to *properly* erase it. Hope this helps and thanks to David Partridge for his input. There is a hand held DAT degausser available, with an oersted rating of 2800, that lists for $169. Please give a call at 800-321-5738 if you are interested. Art
- Cassette House
- e-mail:artmuns@tape.com
- DAT tape - CDR's - Cassettes
- web page http://www.tape.com/ch
- 800-321-5738 "I will use no track before its time"
(INFO FROM: <a href="http://www.solorb.com/dat-heads/digests/V2.900/D921">DAT Digest</a>)
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Radio Shack's High Power Gauss Field is 800 oersteds.
<a href="http://support.radioshack.com/support_video/doc14/14741.htm">Specs</a>
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So as you can see, degaussing DV tapes can be done with the right equipment. Let's see...to erase a DV tape of 1700 Oersteds I need a degausser that can handle 3400 Oersteds. Hmmm, The Radio Shack High Power Bulk Tape Eraser handles 800 Oersteds. No wonder it didn't work.