effects of magnets on video tape

[Brian]

I had an old VHS video tape that I was going to throw out (bulky things).
As a experiment I wanted to find out what it takes to destroy a video tape
using magnets.

I put the tape in front of several loud speakers, i moved it around the
speaker holding it as close to the speaker as I could. I played it back and
there was no damage to the tape.

Next I turned on the vacuum cleaner and held the tape to the motor. I also
switched on a cooling fan and held the tape close to its motor. When
playing it back there was no damage to the video on the tape.

Next I held the tape to a strong magnet as well as a magnet thats designed
to quickly erase audio cassette tapes. I played back the VHS tape and could
not see any damage to the recording.

Maybe if the tape is exposed to a magnetic force over a longer period of
time then it might cause damage to the recording on the tape.

It was a TDK which are of good quality. It may also depend on how strong
the video heads magnetic force is when the recording is made.
So it does seem difficult to destroy a video tape using a magnetic force.

I might try leaving a VHS video tape on top of a speaker for a length of
time to see if that can destroy a VHS video tape recording as an
experiment.


--
Regards Brian

[David Ruether]

"Brian" <bcl...@es.co.nz> wrote in message
news:802584907398072323.0...@free.teranews.com:

8^) Just goes to show that tape can be a pretty darn good
archiving medium...!;-) Thanks!
--DR

[Gene E. Bloch]

You won't ever succeed with speakers and vacuum cleaners, and even an
audio cassette eraser might be too weak for the wider VHS tape.

Get a bulk eraser specifically designated for VHS tape.

--
Gene E. Bloch (Stumbling Bloch)

[Brian]

I don't need to erase the VHS tape but it was more of an experiment to find
out if a VHS tape recording was easy to destroy. I was pleased with the
results as I was concerned that my tapes might get damaged if accidentally
exposed to a magnetic force.

--
Regards Brian

[Paul]

Brian wrote:

>
> I don't need to erase the VHS tape but it was more of an experiment to find
> out if a VHS tape recording was easy to destroy. I was pleased with the
> results as I was concerned that my tapes might get damaged if accidentally
> exposed to a magnetic force.

Try a rare earth magnet extracted from a hard drive.
That might be a bit stronger. The tape should make
contact, for best effect. According to this, you can
get 10x the field strength, compared to a regular magnet.

http://www.dansdata.com/magnets.htm

Paul

[Brian]

Will if it takes a rare earth magnet in contact with the tape to change the
recording then my tapes are safe from getting accidentally destroyed from a
magnetic field. I must try a similar test on a computer floppy disc.

Thanks for the link.


--
Regards Brian

[Gene E. Bloch]

OK, that's cool. In fact, it's nice that you're employing the scientific
method to satisfy your curiosity :-)

[j]

My impression is that you can destroy a floppy disk by doing nothing,
they self destruct on their own. I don't know why that is, but they have
had to be the worst form of storage, probably even worse than zip disks.

Magnetic fields fall off rapidly from their origin, unless designed
otherwise. In the case of VHS tapes, the audio track is closest to the
edge and the video luminance is FM modulated, naturally noise resistant.

For the time, a pretty good design, not as good as Beta, but damned
ingenious.

Jeff
>
> Thanks for the link.
>
>

[Dan San]

Floppy discs don't self destruct. The track alignment is just very fussy. If a floppy stops working it's probably just bad track and head alignment, can be due to temperature sometimes. HDDs use a system to find the tracks and align themselves, floppy discs lacked this, hence problem. Your discs aren't necessarily corrupt, with another drive or some tweaking they may work fine.