Blank/Erased VHS Tapes

[mwplefty]

I was arguing with my father about how unlikely it was for the magnetic tapes to erase after a certain period of time. Does anyone know roughly how long it takes VHS tapes to automatically erase if it's played on an occasional basis? He said 20 years. I thought much longer. He's been paranoid about his 20-25 year old VHS tapes and quickly converted them to DVD. Is he worrying too soon? Should he even be worried at all?

[Ed in Tx]

The old tapes may yet outlive the recordable DVDs! So hang on to those tapes just in case.

I have old VHS tapes from late '70s, some 30+ years old now, that play fine. Only issue I've had is the leader tape on a few fatiguing at the point it's anchored to the take up hub, and breaking. Have to take the tape apart and re-affix it to the hub and all's well.

[Eric H]

Unlikely to erase but the tape itself could degrade and become unplayable at some point, I haven't found many like that yet unless they were stored very poorly.

DVD-r isn't a good solution, I have had quite a few of them (and CD's) become unplayable in a relatively short period of time, far shorter than tape, largely due to the stick on labels that were popular a decade or so ago.

[mwplefty]

Originally Posted by Eric H

Unlikely to erase but the tape itself could degrade and become unplayable at some point, I haven't found many like that yet unless they were stored very poorly.

DVD-r isn't a good solution, I have had quite a few of them (and CD's) become unplayable in a relatively short period of time, far shorter than tape, largely due to the stick on labels that were popular a decade or so ago.

I knew it was more of an "old wives' tale" than anything else, probably just another plea to get everyone to "modernize."

[old_tv_nut]

Tape does not generally erase itself magnetically beyond a possible loss of maybe 3dB due to magnetic domains that weren't firmly aligned, going back to random orientation.

The Cartrivision folks studied this very carefully, as they intended to use a thermal contact printing process for duplicating tapes, and they needed to know what processing was necessary to get maximum transfer. The thermal transfer was like an instantaneous life test. They found that whatever temperature/time profile they used (within reason) the maximum degradation was 3 dB.

Degradation of tape is generally due to chemical/mechanical deterioration, so storage conditions are important, as are the formulation of the plastic base and the binders that hold the oxide on. The oxide itself, however, retains its magnetism well, as far as I know.

I have noticed 8mm camcorder tapes developing increasing dropouts after 20 years, so that would be a reason to make copies.

[mwplefty]

Originally Posted by old_tv_nut

Tape does not generally erase itself magnetically beyond a possible loss of maybe 3dB due to magnetic domains that weren't firmly aligned, going back to random orientation.

The Cartrivision folks studied this very carefully, as they intended to use a thermal contact printing process for duplicating tapes, and they needed to know what processing was necessary to get maximum transfer. The thermal transfer was like an instantaneous life test. They found that whatever temperature/time profile they used (within reason) the maximum degradation was 3 dB.

Degradation of tape is generally due to chemical/mechanical deterioration, so storage conditions are important, as are the formulation of the plastic base and the binders that hold the oxide on. The oxide itself, however, retains its magnetism well, as far as I know.

I have noticed 8mm camcorder tapes developing increasing dropouts after 20 years, so that would be a reason to make copies.

Yes, I know for a fact that the 8mm tapes will deteriorate after several decades. My grandmother's tapes from when my mother was young have been severely damaged so my father advised her to make them into DVD's, which can be done at many electronics stores for a small price.

[packrat79]

Originally Posted by Eric H

Unlikely to erase but the tape itself could degrade and become unplayable at some point, I haven't found many like that yet unless they were stored very poorly.

DVD-r isn't a good solution, I have had quite a few of them (and CD's) become unplayable in a relatively short period of time, far shorter than tape, largely due to the stick on labels that were popular a decade or so ago.

What about gold lacquer DVD-ROM's? They have a rated archival life of 100 years.

[zenith2134]

Hello..Fascination overcomes me with this thread. I have wondered this myself

My father and mother have VHS tapes, taken on an '86ish Hitachi camcorder in 86-88, which exhibit virtually ZERO degradation when viewed today....However, there are a pile of VHS tapes taken in '84 or so on an unknown machine owned by my great-uncle, which are quite lousy and are barely viewable.

The good tapes: TDK 'hi-fi' standard
The bad: JVC archival, ironically.

Which leads me to believe that the machine which recorded the programme originally, is the most important factor.

[Ed in Tx]

Originally Posted by zenith2134

Which leads me to believe that the machine which recorded the programme originally, is the most important factor.

Without seeing the symptom, one common cause of playback problems is alignment differences between the recording machine and the one playing back. This interchangeability problem will show up especially on the slower speeds. At EP speed (aka SLP) the track width the heads lay down is 19 microns wide (1 micron is 1/1000 of a millimeter), so there's not a lot of room for error.

[zenith2134]

Most of the tapes in question were made on 2head camcorder machines, but a few were hifi sound and 4head. In any event, the misalignment of which you speak seems likely....it's rolling noise bar interference which causes the audio buzz and all....some segments are fine, and some are just shot....and the tape itself doesnt appear too battered at these points...so....this is one of the reasons i chimed into the thread.

[Ed in Tx]

I've actually mis-aligned a VCR to a particular tape just to get a decent copy. Then re-aligned the playing VCR afterward. Not recommended if you don't know how to align the tape path, mainly the cylinder entry and exit guides.

[zenith2134]

interesting, Ed...That reminds me of something in the audio world; where a user would adjust vertical tracking angle of his stylus to accommadate a particular label or pressing....in an effort to tame sibilance/splosives.

[Ed in Tx]

I've aligned the playback deck to the tape with audio cassettes and reel to reel tapes too; switch to mono, listen closely and adjust head azimuth for maximum treble then switch back to stereo, to get a decent copy with all the highs (and phase of L-R channels pretty close) to copy to a CD-R.

[bgadow]

I'm not well versed on this but something I've noticed is that many home-recorded tapes that I've found tend to have bad audio, as if it is misaligned. Tape in general seems to have an incredible lifetime. I have some early 80s Beta that looks as good as live, and have mentioned before the paper-backed audio tape I have that must be from around 1950. Still sound like it was just recorded.

[Electronic M]

One way I've heard of VHS tapes erasing themselves with time is when some one would punch a hole in a VHS cassette to be able to record S-VHS on it using a pre S-VHS-ET recorder. This supposedly made good recordings that would only last about a month before becoming unwatchable.

Tom C.