magnetic field

[smartel]

i know a magnetic field would just destroy a vhs tape .. #well maybe not

but what about a vcr ? i mean big loudspeakers like a bass cab

would degaussing be possible if that happened ?

or tracking or it's electronics ..

[Selur]

as far as I remember any normal sized bass wouldn't have a magnetic field that would harm a vhs tape, to properly degauss a tape you need some serious power,.. it might add some noise to the tape, but one could probably not differentiate that given the normal vhs quality.
out of memory I think a normal bass would need to be by a factor of 20 stronger to be on a level vhs erazers used,...
(haven't dealt with such stuff for 20+ years, so if anyone things I'm wrong please correct me)

Cu Selur

[lingyi]

+1

I had a audio tape eraser for cassettes and reel to reel tape that when used on a videotape would at most sometimes cause some tracking errors because it affected the control track on the tape.

As for affecting the VCR, it's possible, but highly unlikely unless the speaker was placed directly on the VCR. Back in the days of CRT TVs, you could see the effects of speakers on them because they would cause colored blobs were the magnets were too close. But because magnetism weakens extremely quickly with distance a few feet distance between the speaker and the TV/monitor would remove any effects.

[smartel]

maybe 2 feet distance between vcr and an ampeg half-stack 4X10 (500w) for a very long period ...more than a year

[JVRaines]

You won't have any measurable effect on a VCR or its tapes at that distance. Mag tape is formulated with fairly high coercivity and requires a powerful magnet close up (right next to it, like a tape head) to change the recorded field.

[johnmeyer]

You won't have any measurable effect on a VCR or its tapes at that distance. Mag tape is formulated with fairly high coercivity and requires a powerful magnet close up (right next to it, like a tape head) to change the recorded field.

That is very true. One time, just for grins, I took a reasonably powerful magnet and passed it over some audio tape. It still played.

[lingyi]

I had some ED-Beta metal tapes that couldn't be affected by my bulk eraser, even on the strip of exposed tape under the door. Even the erase head on a regular Beta machine didn't do anything to it.

[lingyi]

The thread reminds me of people thinking a regular magnet will corrupt/erase the data on a hard drive. Take one apart and inside the drive are powerful rare earth magnets that work the actuators.

I think I still have my bulk eraser somewhere. If I come across it, I'll try it on some old drives.

[abolibibelot]

Side question : can heat, as in, exposure to summer heat, significantly damage VHS tapes ? One summer a few years ago I stored all my tapes under a desk, in front of a window, and I realized weeks later that during the hottest hours the tapes were directly exposed to Sun rays... Haven't tried watching one of them since. I have been planning to digitize them for almost 10 years now, but it's such a daunting task, especially with the desire to do it right and the knowledge that even with the best possible equipments and methods it's going to be pretty lousy anyway... And I'm wondering if that's even worth the trouble, since I haven't watched them in about 15 years, some contain movies of TV documentaries which I have never seen at all, and each day I gather new stuff that I just accumulate, at best I watch 10% of all that mess, and it's getting worse every year ! é_è

[redwudz]

Where I live, it gets well over 110F in the summer. If you were to leave a audio cassette on the car dash, it would be badly warped and unplayable.
VHS tapes would likely fare the same. Don't know if you would have temps like that indoors, but the 'rule' has always been to store magnetic or
optical media in a cool, dark, dry environment for best longevity.

I still have an old bulk VHS tape eraser around. It puts out a very strong oscillating magnetic field,
but still needs to be in direct contact with the tape for several passes to do a full erase.

Reminds me of a movie where a hacker erased his hard drives from the outside of the case with a bulk eraser. Not happening.

Speaker magnets are stationary, just the small voice coil winding moves and it is fairly well shielded by the metal around it.

[JVRaines]

Side question : can heat, as in, exposure to summer heat, significantly damage VHS tapes ?

High heat, especially in combination with high humidity, is bad for tape.

[johnmeyer]

Heat is about the worst thing for any media, including magnetic tape.

[lingyi]

Side question : can heat, as in, exposure to summer heat, significantly damage VHS tapes ?

High heat, especially in combination with high humidity, is bad for tape.

But will it cause fungus? '

- Channeling gamemanico

[redwudz]

I've fortunately converted all my old VHS tapes, and I no longer worry about magnetic, cosmic ray or fungus damage.
Surprisingly, most converted to my preferred MKV H.264/AC-3 format with decent quality.

I had a lot (100+) of VHS LP video from TV caps that were poor quality and most not worth preserving,
but the commercial tapes were OK. I used a Diamond VC500 for the last few after my Canopus ADVC-100 died.

[JVRaines]

Side question : can heat, as in, exposure to summer heat, significantly damage VHS tapes ?

High heat, especially in combination with high humidity, is bad for tape.

But will it cause fungus? '

- Channeling gamemanico

Yes, if you are lucky.

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