Ein Rückblick auf die Geschichte und die kreativen Geister.

The annals of science and industry are littered with the writings of two types of people, the thinkers and the doers. While conception obviously predates construction, there is no shortage of instances where the conception alone, although recorded in some periodical, is not reduced to practice and someone else, either simultaneously or at a later date, finally creates the device in question.

Video recording also had its thinkers and a diligent search of old patents and long forgotten books yields a few of these early concepts. It almost seems as if one searched far enough, one could find a crude drawing made by Leonardo da Vinci proposing a means of committing images to a medium.

Suddenly, the monitors in the room were showing what must have seemed to the audience as an impossibility, for they were looking at an instant playback of the Lodge speech, with an image clarity indistinguishable from the original they had seen a few minutes earlier. There was a hushed silence as those in the room tried to relate this assult on their senses, with their a priori knowledge that TV images could not be immediately repeated by any known device.

As the impact of what was happening before them sank in, the silence was broken by an equally sudden roar of applause, cheers, whistles, and stamping of feet.

The curtain behind the podium opened to reveal a large gray console that looked like a gargantuan audio tape recorder, with overgrown reels of tape on its horizontal top plate. Hovering over this whirring magnetic monster, with looks of obvious relief, were a few of the engineers responsible for developing it.

With the presentation over, the normally staid and dignified executives from television stations all over the country crowded in around the VTR, trapping the operating personnel against the machine, while they pushed, elbowed and stood on chairs to get a glimpse of this latest video marvel.

The VTR crew, who just a few minutes earlier were holding their breath in the fond hope that this hastily assembled contraption of infinite electro-mechanical complexity would perform on cue, were now busily answering questions from excited interrogators who were naturally curious about performance, price and availability.

The prearranged plan had been to record the output of the monochrome camera covering Bill Lodge up to a certain cue point, then the Machine was rewound and put into the "play" mode just as Lodge's comments ended. There was no available monitor for the team behind the curtain to check the playback before punching it up on the TV screens in the other part of the room. As a result, they had to operate on the blind faith that everything was working well. That short silence at the beginning of the playback seemed like an eternity to Ginsburg, Dolby, Anderson and Pfost, four of the key members of the Ampex engineering team.

All the hardships, the concentrated efforts, the endless hours of work, and the frequent disappointments were suddenly swept away in the euphoria of success which triggered off an avalanche of videotape recorders that now permeate the entire television world and represent a billion dollar plus industry.

In the four days following, this small California-based company wrote orders for $4,000,000 worth of their magnetic miracle, which represent one of the most expensive recording devices ever made selling at approximately $50,000. Nevertheless, its obvious benefit to TV operations, at least in the program delay category, was sufficiently attractive to warrant the huge investment that the major networks hastily committed in order to equip themselves with VTR's.

While all of these esoteric prognostications had technical merit, they were too far ahead of existing tape and head technology to warrant much attention from serious experimenters in the field. Instead, the major efforts at that time (late forties, early fifties were directed toward extensions of the known principles of magnetic audio recording by extrapolating those operating parameters into the region of video signals.

Four such known projects were going on, the best publicized one being at the RCA laboratories in New Jersey. Under the direction of Dr. Harold Olson, a man with an excellent reputation in the field of acoustics, a team of researchers built and demonstrated a series of longitudinal, high speed VTR's that made monochrome and color pictures.

Clear across the country, in a well equipped lab on Sunset Blvd. in Los Angeles, another VTR project was under way, under the sponsorship of Bing Crosby. The famous singer's early relationship with the Ampex audio recorder and its rapid rise in popularity must have given him the idea that a similar breakthrough in video would be tremendously profitable. With the help of his brother (who was also his business manager), they set up Crosby Enterprises and hired John Mullin to head up a group of engineers who were to pursue yet another technical approach.

The basic theory was to use division multiplexing with 10 channels covering the split up of the desired video frequency range. A bandwidth of 17 kHz per channel produced a cumulative spectrum of 1.7 MHz, adequate for monochrome reproduction. Sync was recorded on an eleventh track to avoid the distortion effects of the band separation filters.

By 1952 Crosby Enterprises were inviting broadcasters in to look at credible results of off air black and white recordings. There were, however, some severe picture impairments that would require much improvement before the recorder could be considered acceptable to broadcasters. After transverse video recording was introduced, the Crosby project was acquired by the 3M Company as their Mincom Division and was put to other recording tasks in the instrumentation field.

The BBC also saw the potential advantage of a vision magnetic recorder, and in 1952 assigned Dr. Peter Axon to lead a long-term effort in this direction. The machine was called VERA (Vision Electronic Recording Apparatus) and was quite different from its contemporaries. Many of the developments achieved in this recorder served as departure points for subsequent helical VTR's that were developed later.

The half-inch tape moved at 16 feet/sec, and a 21-inch diameter reel gave 15 minutes of playing time. VERA was capable of a 3 MHz bandwidth, a significant achievement for its era in longitudinal recording. The fundamental approach was to separate the video signal into two bands: the first for all low frequencies up to 100 kHz, the second from 100 kHz to 3 MHz. Low frequencies were recorded by FM techniques while the highs were applied to the tape in AM form. The carrier of 700 kHz was modulated upward for sync pulses and downward for peak whites (the opposite of most present systems) and was deviated by plus/ minus 300 kHz.

In playback, the two separate frequency bands were combined to produce an image good enough to put on the air in 1958. VERA had many unique features, among the most notable being heads made of ferrite cores clad with permalloy with a gap width of 0.5 microns and a closed loop tape drive system which held tape speed to 0.04% by locking to an external sync generator and comparing the sync off tape with the reference source.

The BBC terminated the project when it became evident that the transverse approach, introduced by Ampex, would become the standard of the industry. As a matter of fact, Dr. Axon also recognized this potential and shortly after became Ampex's managing director of their Reading operation.

The Japanese develope DESSAN.
While little information was coming out of Japan in those early days, it later became evident that several Japanese organizations were also experimenting with videotape recording. The longitudinal effort was called the DESSAN project and was named after an artistic technique which did the broad brush background first (i.e., low frequencies) and filled in the detail later (high frequencies).

In 1953, Toshiba was experimenting with crude helical scan systems, which five years later evolved into both single and dual head prototypes. The presentation of the first Japanese paper by Norikazu Sawazaki of Toshiba on helical recording, at the 1960 SMPTE meeting in Los Angeles, stirred up quite a controversy about the relative merits of basic VTR formats which is still going on. It also caused Ampex to rush to completion an ill-fated two inch helical recorder (the VR8000) which] was shipped in heavily sealed locked boxes to the following NAB convention in Chicago. Flying different aircraft, Ginsburg and Maxey had the only keys to the locks. It was to be demonstrated only if a competitive broadcast recorder, with a helical configuration, was shown. There were none and the black crates were returned to Redwood City unopened.

Lets anyone wonder at this cloak and dagger scenario, it should be explained that fortunes were made or lost on Ampex stock, often as a result of rumor or innuendo. When Dr. William Glen of General Electric announced the first thermoplastic recorder, which he claimed would challenge the videotape position in television, the mere possibility caused a run on the market which took several years of subsequent evidence that the process was impractical for Ampex stock to recover.

Videotape recording had become big business, and like its counterparts in other high technology fields, it needed constant R & D to keep it ahead of the game.