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Author Topic: Sticky Shed 1. convection oven baking? 2. "un-packing" tape before baking?  (Read 7303 times)

Offline analogfan

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The tapes I have to bake are Ampex 406/407.  The recordings were made '72 - '75 and the tapes have remained in the boxes, essentially unplayed, for many years.

Has anyone used a convection oven for baking tapes with good results?  I have a Jenn-Air electric oven with digital temp controls and the convection fan, built-in.   I also have an external digital thermometer i will use to track the oven temp.

RE: unpacking before baking - how critical is it?

I am concerned about unpacking them on my R2R for fear of losing more of the oxide.  I don't think I can run my OTARI at play speed without the tape contacting the heads.

Any comments would be appreciated.  Thank you, Analogfan/Bob/[email protected]

Offline Tim

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Re: Sticky Shed 1. convection oven baking? 2. "un-packing" tape before baking?
« Reply #1 on: February 28, 2010, 02:58:51 PM »
Here is a good article on baking:

http://www.tangible-technology.com/tape/baking1.html

In it, he highly recommends that the tape evenly packed before baking (if tape edges are sticking out, they could be deformed by excess heat).  If you do this on your Otari, however, since most of the guides are fixed, you will loose some oxide (and therefore some signal).  Ideally, you should remove the headblock and convert the remaining guides to rollers.  Or perhaps find or borrow a deck that has all (or mostly) roller-guides.  To answer you question...yes, I would play the tape before baking, even if your guides are stock.   

I recently read an interview of mastering engineer, Steve Hoffman. He stated he automatically bakes any Ampex tape falling in the 1974 to 1986 range. He just assumes it will need baking.

Tim Leinbaugh
Service Technician
with RTR specialty.

Offline analogfan

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Re: Sticky Shed 1. convection oven baking? 2. "un-packing" tape before baking?
« Reply #2 on: February 28, 2010, 03:41:22 PM »
Thanks Tim,

I thought that was the answer.  I have seen the article but have not read it for awhile.

Are roller tape guides and swing arms with rollers available yet as a kit?  Seems to me I read something about the TP working on that. 

Will I have to go through an alignment procedure if I remove/replace the head block?  I think it comes off as a unit so the tape heads would not be moved?

Thank you again, appreciate your interest and time.

BTW, where are you located in the US?  I am in the Boston area.

Regards, Bob Edwards/Analogfan


Offline Tim

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The kit was talked about, but has not materialized.

Removing the head block should not change alignment.  Another idea is to somehow engage the tape-lifters during play.  That might help.

I'm in the DC area (Fairfax, VA).
Tim Leinbaugh
Service Technician
with RTR specialty.

Offline docb

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Actually the decision was made not to do a kit. Unfortunately this kind of info often gets dispersed across a few different threads.

There have turned out to be enough different variations of the tape guides on the 5050 series - some being incredibly difficult to dismantle for modification and others needing to be completely redone from scratch - that we have decided to keep the guide mods as part of the service we perform here, where we have developed the tools and techniques to work with the various versions of guides without damaging them.
Dan "Doc B." Schmalle
President for Life, Bottlehead Corp.
Managing Director - retired, The Tape Project

Offline Ki Choi

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Hi Bob:

If your Otari is one of the MX5050 series, you can thread the tape around the tension arms and roller guide/ move sensor normally but above the headcover so that the tape makes no contact with fixed guides and heads.  If your spooling motor bearings are good working condition, then there's a good chance you will get nicely packed tape at normal rewind speed.

If you have an access to a Studer A810, you can also thread the tape above the headcovers without making contact with heads and guides.  In addition, you can put the transport into the library mode and wind the tape at lower speed that will result a perfect pack.

The other option is to flip the original tape and mount it as the supply reel and play the tape at 15 ips with tape being threaded above the headcover as described above.  I had once done it to flip the tape when one of the reels I had bought from eBay that had tape wound with oxide on the outside...
Ki Choi

Offline analogfan

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Hi Docb and Ki Choy,

Thank you both for taking time to reply:

Doc, thanks for the feedback on the "kits" but I have to say I am disappointed, as I am sure others will be.  How bad are the fixed guides to do on a 5050 BIII, circa 1993?  Can the roller bearing swing arms be made available or is that also a major installation hassle?

Hello again Ki!  I have learned a lot about the 5050 recording/line out levels to consumer levels in the past few months and solved both of my problems which you helped me with early on.  Thanks for that!  If any one has this problem I am happy to share what I have learned.

Ki, thank you for the several methods to gently unpack the tape.  I am sure many others will be interested!

I don't have access to the a Studer but the other methods are good 2nd alternatives that I will try if I can get the un-packing question resolved as I found NEW INFORMATION (below ) on unpacking, attributed to Ampex/Quantegy.

Another point of view for all who are interested un unpacking tape before baking:

I ran across a paper on tape restoration (contains a lot of good information) as follows:

Title:  Magnetic tape deterioration: recognition, recovery and prevention, by Gerald D Gibson, Library of Congress,  Presented at the IASA Conference in Perugia, August 26, 1996

http://www.unesco.org/webworld/ramp/html/r9704e/r9704e11.htm

which states that Ampex/Quantegy both advise against unpacking because of print through.  Partially quoted as follows:

"Regardless of the time and temperature selected (for baking), do NOT, I repeat NOT, rewind the tape before baking as this will almost certainly increase print-through problems, according to Quantegy/Ampex...."

Soooooo, to unpack or leave packed, that is the question???

Any other points of view?

Anyone try a convection feature in a good electric oven for baking tape ?

Thank you, Analogfan, Bob Edwards



Offline Tim

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What exactly do you you mean by "leave packed" and "un-packing"? Those are confusing terms.

Fast-winding a tape results in tight, uneven packing.  Playing a tape results in even, normal-tension packing.   To prevent damaging the the tape during baking (and to prevent print-through problems), it should have an even, normal-tension pack.   You get that by playing the tape from beginning to end.  The article you quoted said not to bake after fast-wind, which is quite correct. You are not receiving conflicting advice.
« Last Edit: March 02, 2010, 03:03:35 AM by Tim »
Tim Leinbaugh
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with RTR specialty.

Offline analogfan

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Thank you Tim,

What I mean is leave the tape as it was stored (packed), play or move the tape in some way onto another reel (un-packing) prior to baking.

I think I missed the point you clarified.  Appreciate your catching it.

Thank you for the feedback, appreciate it!

Regards, Bob