The Lunar Orbiter tape digitization folks have just posted a commentary that bears reading by all archivists who are holding tapes. You may link to it here. The main site is www.moonviews.com

NASA, in their press conference yesterday held at The Newseum, admitted that the original 14-track 1-inch instrumentation (IRIG) tapes that contained the slow-scan video direct from the moon were most likely recycled and reused for later missions. Apparently, over 350,000 reels of instrumentation tape were recycled by NASA over time. No one apparently thought to preserve the 45-odd reels of the original moon walk.

The loss of the original IRIG tapes of the moonwalk is truly sad because this data could be re-converted to standard television formats using far superior methods than were available in 1969. There may be 2-inch helical Ampex VR-660 video tapes still extant of the slow-scan data,  but those have not surfaced. It appears that all surviving copies of the moonwalk videos are ones that had gone through optical standards converters. An optical standards converter is one that has a monitor displaying the image in real time in the transmitted standard and a television camera taking a picture of that monitor using the desired standard. Even the Australian Broadcasting Corp. tapes would have gone through this type of device, although they would be in PAL rather than the U.S.’s NTSC versions.

Lowry Digital is doing a great job of restoring what they have, but the Polaroid screen shot that survives of the slow-scan monitor is alluring of what could have been preserved. More information is available on the Parkes website and from NASA.

Vigilant migration of data as new storage techniques become available is the only way to assure long-term preservation. Even if the IRIG tapes are found, we are almost at the point where the tapes would be un-decipherable. I think one of my machines could play them (I say think as I’ve never tested it to full 500 kHz bandwidth), but I don’t have the specialized video decoder. NASA apparently preserved some equipment should the tapes ever show up.

This also raises another spectre. We MUST be selective as to what we keep in our archives because if we keep everything we won’t be able to afford it–or find it. This is one of the key jobs that archivists do. However, blindly following retention practices, as was done by NASA for the IRIG Apollo 11 tapes, needs to be tempered by historians as well. Certain small subsets of data (moonwalk slow scan video) are much more important than others (astronauts’ blood pressure and other biometrics throughout the entire flight).

All organizations who keep archives need to address this. In a generation (or less) if we save everything, it will become an overwhelming burden and the high points will be lost if they are not properly indexed.

Oh, and the discussion started about images, but it pertains equally to audio and video. Ike was certainly clear on his thoughts about data tape. As I see it (without following it too closely), the marketplace is consolidating around LTO and appears to be shrinking, so maybe he’s right. I’ve stayed away from data tape in favour of an all-disk solution (for approximately 3 TB of storage at the moment).

When looking at storage for audio, consider a track-hour (i.e. a mono program) at 96,000 samples per second, 24 bits, is about 1 GB, uncompressed. 1 TB is about 1,000 track-hours of material at the normal high-resolution sample rate and bit depth…and that currently fits on one physical drive.

http://www.fixer.com/

I invented the automatic tracking system in 1976 but it is pricey. If you want to pay about $2,000 for a pro-VHS machine, you can get true auto-tracking. Manual tracking works for most tapes. If not, there was a problem with the recording VCR. Alcohol is not good for cleaning heads and tape guides. I always use Xylene and you can buy Xylene at hardware and paint stores. Do not use Xylene on a pinch roller! Have your window open when you use it. I sniffed Xylene for over 30 years and am still okay–okay–okay….I recommend using Xylene for cleaning all components in the tape path except the pinch roller. I recommend Isopropyl alcohol for cleaning pinch rollers. [Some of us are using Formula 409 on pinch rollers—it depends on the pinch roller and its application—Richard]

The scanner surface and the video heads should not require cleaning. The problem is oxide/binder clumping on tape guides and sometimes on the stationary heads. At Ampex, I made it a practice to never clean the scanner surface or the video heads unless an exceptionally high-debris tape had been used.

Another one of my inventions is the scanner surface finish. It is frictionless. My surface finish created so much airfilm that I had to cut deep grooves on the upper half in order to get good head-tape contact.

The JVC HRS9911 is a great VHS machine. Most of the on-line VTR companies are out-of-stock but www.HDTVHOUSE.COM may have it for about $400. EBAY is a possibility.

If you have the Tech Manual for a VHS machine, you can find the RF output terminal and use an oscilloscope to look at the RF and adjust the input and output scanner guides to obtain a proper RF envelope. The Tech Manual should describe how to do this.

Be sure to rotate the tracking control to see both sides of peak RF. This is because you can be fooled by a wide/narrow record/play head combination.

[I asked Jim to provide a brief biography—Richard]

I started at Ampex in 1961 right out of college and enjoyed all 32 years. I worked with great people and learned a lot. I got a BSEE from Cal Berkeley in 1961 but I did not learn anything about electronics at Cal. I learned that stuff at the Univ. of Ampex in Redwood City.

Comments:

Susan Kitchens Posted Mar 19, 2006 2:29 PM