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
