Bulk tape eraser

[Chuck Guzis]

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