Predicted life of audio recorded on magnetic tape

[dave walsh]

I'm think you will be ok in the cloud Red 16 and I don't think it's at all heretical for you to take advantage of contemporary technology. Luddites weren't against progress, per say, you know just the effect it had on THEM I'm sure your info will do better than in one of the government computer systems which always promise security but then have major breaches. The collapse of an early social media site last year [taking years of the subscribers personal and photographic history with it] didn't boost my confidence in the eggy basket approach either. Real clouds don't have an OFF switch There's one, full of rain, heading towards Kent just now.

Dave W

[ricard]

I have a BASF tape, LP35 LH or something like that, it's on a black reel with three mostly recangular holes, so I'm guessing late 70s/early 80s, which, although it doesn't shed in the regular sense, it does emit something from the tape surface which causes machines to gum up, with no visible residue. On one machine, with a particular smooth head, the machine just stops with a squeak after playing for 15 minutes or so. Cleeaning the heads and tape path restores normality for a while, until it gums up again..

I discussed this with Richard L. Hess at some point via email, and he's theory was that it was a variant of SSS which he called Soft Binder Syndrome, where the binder doesn't deteriorate completely.

The interesting thing here though is that it is obviously European tape, not American.

[Ted Kendall]

I had something similar with a reel of 2" SPR50 which had been baked for weeks elsewhere, but still shed oxide. Fortunately, the shed was not sticky - presumably the result of the baking - and provided we kept the heads clean, it worked.

[paulsherwin]

BASF LPR35 is not known for sticky shed problems. Maybe it's been contaminated at some stage?

[jamesperrett]

I've had one reel of Agfa PEM468 go sticky like that too although every other reel of PEM468 that I've played has been fine. The difference with the bad reel was that it came from an American studio whereas all the others have been from European sources. It was definitely PEM468 as the type number was printed on the backing.

[garry71]

Instead of baking tapes, would putting them in a container of slica gel, or rice (like when you drop your phone in a puddle) be any good for removing moisture?

[TIMTAPE]

I guess that would provide a very low humidity in a small space but it would probably take a very long time for the moisture in the binder to be lowered. I believe some use a vacuum system but apparently that also takes a long time. I have some silica beads which when dry are blue coloured and when moist go a dirty brown. Interestingly, to get them back to dry ( blue ) the instructions say to heat them up.

[Ted Kendall]

Originally Posted by jamesperrett

I've had one reel of Agfa PEM468 go sticky like that too although every other reel of PEM468 that I've played has been fine. The difference with the bad reel was that it came from an American studio whereas all the others have been from European sources. It was definitely PEM468 as the type number was printed on the backing.

There was some trouble with 468, although this was confined only to a few batches. An alternative approach for playing sticky tapes, used by Marie O'Connell at Auckland University, is a drip feed of alcohol onto the tape. Messy, and more "one-shot" than baking, but effective.

[garry71]

I've wrapped a sticky tape in some paper towel, and put it in a container of rice. I'll leave it a couple of weeks, and see how it goes.

Just thought, has anyone tried it in a microwave on a low setting, or would that damage the recording?

[Ted Kendall]

Not a good idea. The popular solution, used in many places you'd think would go for something much more complex, is a food dehydraytor, preferably supplemented by a temperature probe. The window is fairly narrow - below 50C, not much happens, but sustained 55C or above can cause noticeable print-through. Baking time used to be about 24 hours for a quarter inch reel, but this has gradually increased to several days.

[dave walsh]

The amount of of knowledge expressed so far re the recovery and preservation of magnetic tape, would appear to support my comment [at post 31*] about Archivists tapping into other available areas. I listened to the BH piece from Sunday in which Richard Rahft expressed his concerns about "professional" machines not being available in the future to conserve magnetic material. His first choice from the Archive ie Nelson Mandela's Dictabelt speech, somewhat countered this as the source hardware would not have been so high end and I think the other two were disc based! He is retiring from a distinguished thirty seven year career at the British Library and it's my guess that he has spent most of that time seeking more resources and funding.

In an ideal world, organisations like The BL, The Beeb, The National Sound Archive [is that still separate?] The Science Museum and others etc would be much more integrated into an overall Sound and Vision Structure of Record-for the Nation. It could incorporate any public or private sources of whatever nature including, for example, on the calamitous Bletchley Park site... to everyone's advantage! Currently it seems to be very much disjointed and subject to random events, social division and/or individual organisational priorities.

I find it ironic that despite such a multitude of items to choose from, I recognised all three examples from previous airings. I fact I've been mentioning Miss Dibner's 1953 bread making item for twenty years or so, when I recorded it from [I think] either R4's Today program or The World At One "They gets they wather" amazing! I always suspected that it was illustrative of Viking influence from across the North Sea but I'm no more an expert in languages than I am in recording techniques

Dave W

[hillmanie]

Is there any significance other than cosmetic in the colour of tapes? The vast majority of mine are mid brown, some are black and one only an unusual reddish blonde. (If it were a girl you might say it was hue 'Titian')
T

[andrewferguson]

Originally Posted by TIMTAPE

The oldest tapes I've dealt with were paper based Soundmirror tapes from around 1950. Like acetate the paper could break or tear but at least they didn't stretch. The breaks were clean and could be spliced together.

A problem with some was that the layers tended to stick to one another when the tapes were unspooled. Not like Sticky Shed where the tape itself is soft and gooey, but more one side probably "catching" in the crevices of the other. Once unspooled, on respooling there was no adhesion but a year or so later the winds had started to stick together again. I guess there had been time for one side of the tape to "conform" to the crevices in the other and they kind of interlocked like pieces in a jigsaw puzzle.

I think I've got one tape that's like that. It's labelled as "Scophony Baird Cine-Soundmaster". There's a handwritten note at the top of the box, "47/6", which might be a bit too early to be a date (1947).

I haven't yet tried playing it because it's on a 7-inch reel and my machine only takes 5-inch reels. Can these tapes be played back on any deck, or am I in for a difficult hunt for the original equipment?

Picture of the tape in question attached.

[Ted Kendall]

47/6 is probably the price - £2.37 1/2p in modern parlance. More likely to be early 1950s. The first Baird machine was full track, later changed to half track. The full track may have followed the Soundmirror pattern and been of 4.5mm width down the centre of the tape. Best to have it played on a decent CLT transport to minimise the risk of snapping and increase the chances of getting a good transfer first time.

[TIMTAPE]

Originally Posted by andrewferguson

Picture of the tape in question attached.

Thanks Andrew. Would you mind also uploading a picture of the tape on the reel with a short section of both sides of the actual tape exposed? That could narrow things down.

Tim

[andrewferguson]

Originally Posted by TIMTAPE

Would you mind also uploading a picture of the tape on the reel with a short section of both sides of the actual tape exposed? That could narrow things down.

"soundmaster-reel" is the reel with the tape.

"soundmaster-inner" is the side of the tape that faces into the reel when it is wound up. Due to it being the darker and shiner side, I think it is the magnetic side (although I could be wrong!).

"soundmaster-outer" is the side of the tape that faces out of the reel when it is wound up.

The tape certainly looks as through it's a paper-based tape, rather than plastic-based. You can see in the "soundmaster-reel" image that the exposed end of the tape has crumpled and torn in places in a way that looks much more paper-like than plastic-like.

[Ted Kendall]

That's Soundmirror-type paper tape. The coating is closely related to black paint.

Apropos, I had to deal with a dstressed tape today. EMI H77 on a metal NAB spool, which had been saturated with water from a wet cardboard box for several years. The state of the reel can be imagined. First job was to dunk it in warm water with washing-up liquid and get the loose alumina off. Library wind on an A810, bypassing the headblock, when a lot more fell off. Rewind onto a clean spool at normal speed, lightly pinching the tape through a wet-wipe. Two more wind-throughs like that. The first few turns needed a scrub to get the alumina off. Set up on playback machine with strategically placed Q-tip next to erase head and away we went. Tough stuff, this H77!

[jamesperrett]

Originally Posted by Ted Kendall

There was some trouble with 468, although this was confined only to a few batches. An alternative approach for playing sticky tapes, used by Marie O'Connell at Auckland University, is a drip feed of alcohol onto the tape. Messy, and more "one-shot" than baking, but effective.

I ended up using Richard Hess's recommendation of interfacing fabric over the erase head to catch the worst of any shedding which allowed me to play the tape in segments of a minute or two before needing to clean the heads again. He also suggested soaking the fabric in cyclomethicone (and I bought some in preparation for this) but I didn't use it in the end.

[TIMTAPE]

Marie O'Connell's Isopropanol method can be seen as both lubrication and cooling of the "soft" tape just before it passes over the repro head. Richard Hess has also described the "cold play" technique where the tape is played on a machine sitting inside a refrigerator. To accommodate say a Studer A80, it would need to be a sizeable fridge!

[barretter]

Originally Posted by dave walsh

In an ideal world, organisations like The BL, The Beeb, The National Sound Archive [is that still separate?] The Science Museum and others etc would be much more integrated into an overall Sound and Vision Structure of Record-for the Nation.

In fact I've been mentioning Miss Dibner's 1953 bread making item for twenty years or so, when I recorded it from [I think] either R4's Today program or The World At One "They gets they wather" amazing! I always suspected that it was illustrative of Viking influence

Dave W

The National Sound Archive (previously the British Institute of Recorded Sound) located in South Kensington was incorporated into the British Library in 1983 and its assets were mostly transferred to the new building on Euston Road in 1997 but some of them are stored in other buildings around London and quite a lot seem to have been sent to the British Library site in Boson Spa near York.
A big problem at the moment is that quite a lot of the old stock has not yet been entered fully onto the British Library Sound and Moving Image Catalogue. Lots of LPs appear on it just as a maker's number with no further details.

"They" is a Scandinavian import. Before the Viking invasion the Old English for "they" was "hie". "The" is also a Scandinavian import.