[QuadList] QuadList Digest, Vol 21, Issue 22

[rabruner at aol.com]

The Bell and Howell/Rank facility in Northbrook, IL, occupied several buildings, each dedicated to a different method of duplication, one for real time in-cassette (about 7,000 Panasonic duplicators), one for TMD (The Otari machines) one for the Sprinter stations, and one for their proprietary open reel 2x real time process.  They did a lot of original research in the field of duplication in-house and with various R&D partners.  Some of their work on direct recording in conjunction with Panasonic became commercially available as the "HQ" mods to the VHS format. They also experiemented with technology from Ives Faroudja.  The Otari/Dupont joint venture is another example. They experimented with a number of variations of the loop bin trying to solve the CLD problem. By the time I left there were some promising ideas, but nothing was operational yet.  The copies made by TMD (the Otari process) produced about 1-1/2 times the flux on the copy as a direct machine recording.  The effect was to produce dubs with very high s/n compared to a direct recording. One use envisioned for TMD was dubbing movies in 6 Hr mode, as the attendant savings in tape made using the process financially attractive and the shorter masters eased the burden caused by the CLDs.  Focus group testing showed good acceptance for the picture quality and there was a lot of interest in the process for making inexpensive point of sale tapes for distribution in non standard outlets like gorcery stores, etc.  
      B&H used a mirror master recorder built by Ikegami, known in this country more for TV cameras and video monitors. In Japan they built a "golden machine" intended for making alignment tapes.  This was an open reel recorder that, at first glance looked a lot like an Ampex 403 audio machine with a VHS scanner on it.  Both the picture quality and mechanical standards of the recordings were very high, but the machine would not pass copy guard, which was another factor that limited its utility for duplicating movies as opposed to other types of tapes.
     Both TMD and the open reel 2x process were carried out in 'clean room' environments, temperature and humidty controlled, filtered a/c, and everyone in the area wearing bunny suits with hair and shoes covered, all access over tack mats at the doors, etc.  B&H was very aggressive about quality control and had a very good record in that regard. All the master transfers used for making VHS dubs were from first generation double system 1-inch tapes using Sony BHV-1100As running in sync with picture on one, and sound as pseudo video on another.  
     Because it was not possible to get any manufacturers C-format machine to run at 2x speed, the 2x plant used B-format machines, specially modified for 2x operation. It was much easier to spin the smaller scanners at 2x. The whole system, monitors, machines DAs, etc. even the Dolby audio processing, had to be adapted for 2x frequency.  The recorders themselves were custom designed and built just for B&H.  The VHS scanners had specially wound rotary transformers for the 2x frequencies and modified pole pieces. The recorders contained only driver amplifiers for sound, picture and chroma as these signals were developed in high quality modulators and then routed out to the machines as RF at 2x frequency.  In general, the process worked well and produced very good picture quality.  It offered a considerable increase in throughput.  Besides making every dub in half the time, the reel to reel nature of the process meant that tapes only had to be changed every 20 passes, a big savings in efficiency.  They used dual masters to eliminate any delay for rewinding the master, and the duplicators were started in waves so that only five or ten percent of them were having tape changes at any one time.  The main bugs in the process were in the duplicator machines and included difficulty controlling tape tension within specifications and accelerated wear on the head drums. 
Bob Bruner
W9TAJ

Bob:


 Thanks for the detail on the Otari system.  I've uploaded a copy of the Sony brochure for their system which used magnetic transfer as was used with the quad duplicator.  I believe their bin system also cured the problem with the loop folds and regular tape was used for the dubs.  The brochure also shows the Sony mirror master recorder.
 
http://www.digitrakcom.com/TechDocs/SONYsprinter.pdf
 

In the 1980s, Sony manufactured a high-speed 1/2 duplicator called the Sprinter 5000.  (S-printer)  It was first designed for Beta and then Sony sadly converted it to VHS. This machine had just one station and ran at 16.6 ft/sec.
  Later, a new model 800 was introduced with a endless master loop that vibrated on a horizontal loop bin, much like
 those vibrating football game tables of the 1050s. It's speed was then almost doubled to 8 meters/sec and it's
 effective duplication speed was increased to almost 240x for SP and 720x for EP VHS.   I built a facility for
 Allied Film & Video in the 1980s that housed 16 of these machines and also developed an endless master bin for
 the first 5000 Sprinter.



 
In the late 1980s, Otari took over a joint research project started by Dupont and Bell & Howell to develop the TMD. (Thermo Magnetic Duplicator)  Dupont wanted to sell chromium and Bell & Howell owned several large VHS duplication facilities in Chicago at the time.  They later became Rank and moved much of the operations to Little Rock, AR.  The technology was similar in mechanics and magnetic printing process, however instead of using a bias field to erase iron tape, a laser was used to heat chrome tape to Curie point and erase the tape.  Chrome tape needed a much lower temperature to accomplish this and the quality was quite good.  Otari had 2 problems besides being late in the game.  Chrome tape was more expensive and their loop bin was vertical instead of horizontal.  This meant the weight of longer movie masters meaning more tape could crease the tape, where as horizontal loop bins didn't have this problem.  However, by the time Otari had a competitive product out in the field, Sony had almost saturated the VHS high-speed duplication business as VHS was reaching maturity.
 
While Bell & Howell started as the largest duplicator, Technicolor later became the largest US and then worldly duplicator.  Both companies started with 10s of thousands of real-time duplicators.  B&H/Rank first implemented 2x machines using large pancakes of blank tape that were later cut into separate video cassettes like Sprinters and TMDs.  Then Panasonic made a 2X in cassette duplicator especially for Rank then later other smaller competitors and Technicolor later introduced their own 3x in cassette duplicator.  Cinram followed as well with a 2x in house design.  
 
Technicolor became the king with the most Sprinter duplicators boasting around 80 unites between Livonia, MI and Camarillo, CA and more around the world.  The largest Sprinter installation ever was a facility I designed and built in Alphaville, Brazil in suburban Sao Paulo, where Videolar had over 100 Sprinters in one very large clean room.  High-speed duplication at one time was at least 50% of the movie business of which probably 80 to 90% was Sony's Sprinter.  Oh yes, all good high speed operations were typically conducted in class 1,000 or better rooms.  As time went on, the vendors advertised class 10,000 in order to sell more product.  You need massive amounts of properly directed air flow  (we had 3 air changes per minute) and lots of 0.1 to 0. 5 micron HEPA filters.  
 
Finally, let's talk about cleanliness in Quad vs. VHS when it come to high-speed duplication.  As you know, it is a contact printing technology so cleanliness affects transfer quality.  One second of Quad time represent 2" times 15" per sec. tape speed yielding 30 square inches of magnetic information describing 1 second of video.  Whereas 1 second of VHS tape time represents 1/2" times 1.3" per sec. tape speed yielding 0.65 square inches of magnetic information describing 1 second of VHS SP.  AND one 1/3 that or less than 0.22 square inches of tape for VHS EP.  Cleanliness and intimate contact are far more important when you have around 1/50th and 1/150th  respectively less real estate to work with.
 
 


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://quadvideotapegroup.com/pipermail/quadlist_quadvideotapegroup.com/attachments/20100311/0e47fb07/attachment-0003.html>