A Chronology of Magnetic Recording

by David Morton

---

1878 - Inspired by a visit to Edison's laboratories in Menlo Park, New Jersey, a prominent American mechanical engineer named Oberlin Smith conceived the idea of recording the electrical signals produced by the telephone onto a steel wire. He files a patent caveat but not a formal patent.

1888 - Oberlin Smith, deciding that he will not pursue his idea, "donates" it to the public by publishing his ideas about magnetic recording in the journal 'Electrical World'.

1889 - Danish inventor Valdemar Poulsen re-discovers ( perhaps after seeing Smith's article or the Tainter patents ) the principle of magnetic recording. Over the course of the next few years he produces practical sound recorders for steel wire and tape. He takes patents in Denmark, the United States, and elsewhere and attempts to sell his patent rights to investors. The machine, called the Telegraphone utilises a steel wire wound helically on a cylinder rotating under an electromagnet connected to a carbon microphone or an earphone. It is described as a device to record telephone messages in the absence the called party.

1900 - Poulsen's first major demonstration of the Telegraphone takes place at the Paris International Exhibition of 1900. The Telegraphone is desribed in glowing terms by the technical and scientific press as superior to the phonograph and a great advance in physics as well.

1903 - The American Telegraphone Company formed in Washington, D.C.to manufacture the Tele graphone. A manufacturing facility in Wheeling, West Virginia set up to make the machines, and the company makes a large public stock offering. American Telegraphone creates several distributorships across the country to handle service and sales. Telegraphone publicity over the next decade or so promotes the various models of the machine as a dictation system and an automatic telephone recorder.

1910 - American Telegraphone, failing because of bad management and production problems, moves production to Springfield, Mass.

1911 - Lee DeForest, then working for the Federal Telegraph Company, is asked to develop an amplifier to allow the recording of high-speed radio telegraph messages received on a type of receiver called the Tikker. Deforest uses his Audion tube, invented in 1907, to make his first practical electronic amplifier. DeForest later tries to apply the amplifier and Telegraphone to the making of motion picture soundtracks, but the work does not result in a practical system.

1918 - American Telegraphone enters receivership after having sold only a few hundred machines. The company remains in existence until 1944 when it is finally disolved.

Early 1920s - German inventor/entrepreneur Curt Stille modifies the Telegraphone to use electronic amplification and markets the patent rights to the device, a wire recorder, to German and British companies.

1925 - Stille and another German, Karl Bauer ( a licensee of the Stille wire recorder patents ), market an improved wire recorder telephone answering/dictation machine called the Dailygraph. The machine was manufactured by the Vox company, a lso of Germany. Later versions of the Dailygraph include provisions for a cartridge, apparently the first use of a cartridge-loaded medium.

c. 1928-29 - A British motion picture production company, Ludwig Blattner Picture Corporation, takes a license to manfacture Stille technology. The firm unsuccessfully tries to make and distribute movies with a synchronized soundtrack on wire. Later machines, modified by Blattner, use steel tape instead of wire.

Radio could be recorded from the late 1920's on machines like the huge Blattnerphone, or the Marconi-Stille. The sound was recorded magnetically on rapidly-spinning reels of steel wire. Editing could only happen with the aid of wire cutters and welding equipment, so the machines were only really used to record broadcasts for later repeats. So expensive were the machines that wire was often re-used, rather than kept for archiving.

Source: http://ftp.bbc.co.uk/radio4/drama/techie.html

1930 - Bell Telephone Laboratories initiates a major research effort in magnetic tape recording under the direction of Clarence N. Hickman. By 1931, prototypes or designs are completed for a steel tape telephone answering machine, a central-office message announcer, an endless loop voice-training machine, and a portable, reel-to-reel recorder for general purpose sound recording. None of these enter production. AT&T's official policy on telephone recorders is that they will not be allowed on public telephone lines.

The German, Stille, and Marconi form the Marconi-Stille Company which builds the first steel band recorders for the BBC: the specifications are the following: width 3mm (1/8"), thickness: 80 cm (3x10-3 mil), speed: 1.5 m/s (60 ips), mass of a full reel: 25 kg (55 lbs); fairly dangerous use (risk of deep cuts). 1931-32 - Blattner sells an experimental steel tape recorder to the BBC but goes bankrupt the same year. Meanwhile, the British Marconi Wireless Telegraph Company purchases the U.K. rights to the Stille patents. The BBC and Marconi jointly produce several steel tape recorders and introduce them to BBC Empire service by 1932. Similar steel tape recorders are used in radio service in Canada, Australia, France, Egypt, Sweden, and Poland. Because the machines depend on a special steel tape made in Sweden, supplies are threatened when World War II begins.

AEG, a large German electrical manufacturer, purchases the patent rights of the independent inventor Fritz Pfleumer, who after 1928 patented a system for recording on paper coated with a magnetizable, powdered steel layer. AEG sets about designing a tape recorder, while it collaborates with the German chemical firm I.G.Farben to develop a suitable tape. I.G.Farben experiments with tape coated with carbonyl iron powder, made under a proprietary process and used in inductor cores.

c.1933-35 - Echophon company, another licensee of the Stille patents, develops the Textophon, a dictation machine using steel wire. Echophon is later purchased by ITT and made part of the subsidiary firm C. Lorenz, a manufacturer of telephone equipment. C. Lorenz, with the help of engineer Semi J. Begun, later markets a steel tape recorder that finds wide use in European telephone authorities for telephone recording purposes and by German radio networks for mobile recording.

1935 - An improved AEG recorder, dubbed the "Magnetophon", is demonstrated by recording the London Philharmonic Orchestra. The RRG ( the German radio authority ) begins to use the Magnetophon for broadcasting, replacing the earlier C. Lorenz recorders.

1938 - S.J. Begun of C. Lorenz leaves Germany to start a new career in the United States. In 1939 he takes a job at the Brush Development Company of Cleveland, Ohio.

1939-44 - Sales of Magnetophons total 379 units. That figure rises to 937 by 1943-44.

1939-45 - At the Brush Development Company, S. J. Begun develops steel tape and coated-paper tape recorders. Between 1942 and 1945 the company designs and successfully sells to the military various types of recorders utilizing plated media in the form of tapes, disks, and wire.

1941Weber and Von Braunmuhl from AEG develop the high frequency biasing: the improvement is decisive and the "Magnetophon" becomes a machine of excellent quality. 1945 - The Armour Research Foundation of the Armour Institute of Technology invents an improved wire recorder. The Institute succeeds in selling several thousand to the American army and navy, and after the war sells licenses to dozens of American and European manufacturers to make wire recorders.

American and British technical investigators "discover" the Magnetophon in Luxembourg, France, and other places formerly occupied by the Germans. By Spring, these investigators begin gathering information about the production of tape recorders and tape, and the information is published by the U.S. Department of Commerce. German patent rights on the technology are seized by the U.S. Alien Property Custodian.

Former serviceman John T. Mullin demonstrates a captured Magnetophon to the Institute of Radio Engineers. Performer Bing Crosby works with Mullin to use the Magnetophon for radio broadcasts on ABC.

Three former Armour Research Foundations employees start Magnecord Corporation in Chicago to make a high quality wire recorder. Plans for the wire recorder are soon dropped, and the group in 1949 introduces a tape recorder, the PT-6. The corporate life of Magnecord ends in 1957 when it is purchased by Midwestern Instruments, Inc.

1946-47 - The first Amour Research Foundation- licensed wire recorders appear in the American market, manufactured by Pentron, Pierce Wire Recorder company, and others. Brush Development company introduces its Soundmirror paper tape recorder developed in 1939-40. A Brush licensee, Amplifier Corp. of America, introduces the Magnephone tape recorder.

Minnesota Mining and Manufacturing ( later 3M Corp. ) introduces a line of sound recording tapes, including type #100, a paper based tape, and type #110, a plastic based tape. Type #111, a plastic based tape with an improved oxide, becomes the industry standard.

1947 - Rangertone Inc., of New Jersey introduces a professional tape recorder based on the Magnetophon.

1948 - Ampex corporation, using Armour Research Foundation and German expertise and designs, produces its first professional tape recorder, the Model 200.

1949-50 - Magnecord introduces two-channel tape recorders, and begins making stereo recordings of music for demonstration purposes.

1948-49 - Sony Corporation begins its efforts to design a tape recorder.

1950 - The first catalog of recorded music on tape appears in the United States. It is offered by Recording Associates company.

1951 - Bing Crosby Enterprises, the research team funded by Crosby and headed by engineer John Mullin, demonstrate a crude video recording system.

1956 - Ampex Corporation demonstrates its first video recorder, the VR1000. The machine, which recorded only monodchrome signals takes the industry by a storm and quickly becomes the standard.

On November 30, the first videotaped material on a TV show airs. It is "Douglas Edwards and the News" on CBS.

1957 - Price of first commercial blank video tape offered by the 3M Corp. listed as $307 per reel.

1958 - The same year that stereo LP's appear on the RCA-Victor label, RCA introduces stereo tape, in a cartridge format requiring a special player. The system flops almost immediately, though its production continues by a licensee, Bell Sound, until 1964.

1962-64 - Phillips company of the Netherlands introduces the Compact Cassette, a portable tape recorder using a small cartridge.

1965 - Ford and Mercury, in conjunction with Motorola and RCA-Victor records, introduce the "Stereo-8" (or "eight track" ) format tape players as an option on certain luxury models. The medium becomes the first truly successful form of recorded music on tape in the consumer market. 8-track tapes discontinued around 1980.

1969-70 - DuPont and BASF begin offering chromium dioxide recording tapes.

1970 - Sony introduces the U-Matic videotape recorder. The format does not succeed well as a consumer product, but achieves great success in schools and television stations.

1975 - Sony introduces the Betamax home video system. By using a convenient cartridge and offering the product at a low cost, Beta quickly takes off.

1976- Panasonic and JVC introduce a competitor to Betamax, the Video Home System ( VHS ) system.

1978 - Sony introduces the first digital recorders. These were professional, open reel PCM recorders for the studio.

1984 - Sales of recorded compact cassettes (audio cassettes) exceed LP sales for the first time.

Sources:

http://www.rci.rutgers.edu/~dmorton/mrchrono.html
http://www.canorus.com/evercloser/nagra/Profile.html
http://ftp.bbc.co.uk/radio4/drama/techie.html

SOME FACTS ABOUT VIDEO RECORDING

Video Recording

In the early days, film was the only medium available for recording television programmes. Thoughts turned to magnetic tape, which was already being used for sound, but the greater quantity of information carried by the television signal demanded new studies. During the 1950s, a number of American companies began investigating the problem.

---

Television Cameras

In the 1920s, American engineer, Philo Taylor Farnsworth devised the television camera, an image dissector, which converted the image captured into an electrical signal.

---

Television Cameras

The pick-up tube is the main element governing the technical quality of the picture obtained by the camera. The first electronic cameras using iconoscope tubes were characterised by very large lenses, necessary to ensure enough light reached the pick-up tube.

---

Video Stills - Digital Photography

The still video or digital camera (the Sony Mavica single-lens reflex) was first demonstrated in 1981. It used a fast-rotating magnetic disc, two inches in diameter, recording on it up to 50 images formed in a solid-state device in the camera. The images were played back through a television receiver or monitor, or printed out.

---

The History of Recording Technology

Tape Recording Technology - Audio and video magnetic recording has had greater impact on broadcasting than any other single development since the invention of radio/TV transmission itself.

BROADCAST VIDEO

Quad

A reel of 2-inch quad videotape compared with a modern-day miniDV videocassette

The first practical professional videotape machines capable of replacing kinescopes were theQuadruplex machines introduced by Ampex on April 14, 1956 at the National Association of Broadcasters convention in Chicago. Quad employed a transverse (scanning the tape across its width) four-head system on a two-inch (5.08 cm) tape, and linear heads for the sound track. CBS first used the Ampex VRX-1000^[11] Mark IV at its Television City studios in Hollywood on November 30, 1956 to play a delayed broadcast of Douglas Edwards and the News from New York to the Pacific Time Zone.^[11][12] On January 22, 1957, the NBC game show Truth or Consequences, produced in Hollywood, became the first program to be broadcast in all time zones from a prerecorded videotape.^[13] Ampex introduced a color videotape recorder in 1958 in a cross-licensing agreement with RCA, whose engineers had developed it from an Ampex black-and-white recorder.^[14]

Although Quad became the industry standard for over 20 years, it had drawbacks such as an inability to freeze pictures, and no picture search; also, in early machines, a tape could reliably be played back using only the same set of hand-made tape heads, which wore out very quickly. Despite these problems, Quad could produce excellent images. Subsequent videotape systems have used helical scan, where the video heads record diagonal tracks (of complete fields) on to the tape.

Very few early videotapes still exist.^[15] While much less expensive and more convenient than kinescope, the high cost of 3M Scotch 179^[11]and other early videotapes ($300 per one-hour reel)^[16] meant that most broadcasters erased and reused them, and (in the United States) regarded videotape as simply a better and more cost-effective means of time-delaying broadcasts than kinescopes. It was the four time zones of the continental United States which had made the system very desirable in the first place.

Type C & Type B

The next format to gain widespread usage was the 1" (2.54 cm) Type C format from 1976 onward. It introduced features such as shuttling and still framing, but the sound and picture reproduction attainable on the format were of just slightly lower quality than Quad (although 1" Type C's quality was still quite high). However, unlike Quad, 1" Type C machines required much less maintenance, took up less space, and consumed much less electrical power.

In Europe a similar tape format was developed, called Type B. Type B machines (also known as BCN) used the same 1" tape as Type C but they lacked C's shuttle and slow-motion options. The picture quality was slightly better, though. Type B was the broadcast norm in continental Europe for most of the 1980s.

Cassette formats

A U-matic tape

In 1969, Sony introduced a prototype for the first widespread video cassette, the 3/4" (1.905 cm) composite U-matic system, which Sony introduced commercially in September 1971 after working out industry standards with other manufacturers. Sony later refined it toBroadcast Video U-matic or BVU. Sony continued its hold on the professional market with its ever-expanding 1/2" (1.27 cm) component video Betacam family (introduced in 1982), which, in its digital variants, is still among the professional market leaders. Panasonic had some limited success with its MII system, but never could compare to Betacam in terms of market share.

The next step was the digital revolution. Among the first digital video formats Sony's D-1, which featured uncompressed digital component recording. Because D-1 was extremely expensive, the composite D-2 and D-3 (by Sony and Panasonic, respectively) were introduced soon after. Ampex introduced the first compressed component recording with its DCT series in 1992. Panasonic trumped D-1 with its D-5 format, which was uncompressed as well, but much more affordable.

The DV standard, which debuted in 1996, has become widely used both in its native form and in more robust forms such as Sony's DVCAMand Panasonic's DVCPRO as an acquisition and editing format. However, due to concerns by the entertainment industry about the format's lack of copy protection, only the smaller MiniDV cassettes used with camcorders became commonplace, with the full-sized DV cassettes restricted entirely to professional applications.

For camcorders, Sony adapted the Betacam system with its Digital Betacam format, later following it up with the cheaper Betacam SX andMPEG IMX formats, and the semiprofessional DV-based DVCAM system. Panasonic used its DV variant DVCPRO for all professional cameras, with the higher-end format DVCPRO50 being a direct descendant. JVC developed the competing D9/Digital-S format, which compresses video data in a way similar to DVCPRO but uses a cassette similar to S-VHS media.

High definition

The introduction of HDTV production necessitated a medium for storing high-resolution video information. In 1997, Sony bumped its Betacam series up to HD with the HDCAM standard and its higher-end cousin HDCAM SR. Panasonic's competing format for cameras was based on DVCPRO and called DVCPRO HD. For VTR and archive use, Panasonic expanded the D-5 specification to store compressed HD streams and called it D-5 HD.

THE STORY OF VIDEO TAPE

From Wikipedia, the free encyclopedia

Videotape is a means of recording images and sound on to magnetic tape as opposed to movie film. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram. In most cases, a helical scan video head rotates against the moving tape to record the data in two dimensions, because video signals have a very high bandwidth, and static heads would require extremely high tape speeds. Videotape is used in both video tape recorders (VTRs) or, more commonly, video cassette recorders (VCRs) and video cameras. Tape is a linear method of storing information and, since nearly all video recordings made nowadays are digital, it is expected to gradually lose importance as non-linear/random-access methods of storing digital video data become more common.

Early formats

The electronics division of entertainer Bing Crosby's production company, Bing Crosby Enterprises (BCE), gave the world's first demonstration of a videotape recording in Los Angeles on November 11, 1951. Developed by John T. Mullin and Wayne R. Johnson since 1950, the device gave what were described as "blurred and indistinct" images, using a modified Ampex 200 tape recorder and standard quarter-inch (0.6 cm) audio tape moving at 360 inches (9.1 m) per second.^[1][2] A year later, an improved version, using one-inch (2.6 cm) magnetic tape, was shown to the press, who reportedly expressed amazement at the quality of the images, although they had a "persistent grainy quality that looked like a worn motion picture". Overall, the picture quality was still considered inferior to the best kinescope recordings on film.^[3] Bing Crosby Enterprises hoped to have a commercial version available in 1954, but none came forth.^[4] BCE demonstrated a color model in February 1955, using a longitudinal recording on half-inch (1.3 cm) tape, essentially similar to what RCA had demonstrated in 1953 (see below). CBS, RCA's competitor, was about to order BCE machines when Ampex introduced the superior Quadruplex system (see below).^[5]

RCA demonstrated the magnetic tape recording of both black-and-white and color programs at its Princeton laboratories on December 1, 1953.^[6][7] The high-speed longitudinal tape system, called Simplex, in development since 1951, could record and play back only a few minutes of a program. The color system used half-inch (1.3 cm) tape to record five tracks — one each for red, blue, green, synchronization, and audio. The black-and-white system used quarter-inch (0.6 cm) tape with two tracks, one for picture and one for sound. Both systems ran at 360 inches (9.1 m) per second.^[8] RCA-owned NBC first used it on the The Jonathan Winters Show on October 23, 1956, when a pre-recorded song sequence by Dorothy Collins in color was included in the otherwise live program.^[9][10] The BBC experimented from 1952 to 1958 with a high-speed linear videotape system called VERA, but this was ultimately unfeasible. It used half-inch (1.27 cm) tape traveling at 200 inches (5.08 m) per second.

Home video

VCRs

Bottom view of VHS videotape cassette with magnetic tape exposed

The first consumer videocassette recorders were launched in 1971 (based around U-matic technology), but it was not until Sony's Betamax (1975) and JVC's VHS (1976) were launched that videotape moved into the mass market, resulting in what came to be known as the "videotape format war", which VHS ultimately won. Videocassettes finally made it possible for consumers to buy or rent a complete film and watch it at home whenever they wished, rather than simply catching it at a movie theatre or having to wait until it was telecast. It also made it possible for a VCR owner to record films and other television programs "off the air". This caused an enormous change in viewing practices, as one no longer had to wait for a repeat of a program that had been missed. The shift to home viewing also changed the movie industry's revenue streams, because home renting created an additional "window" in which a film could make money. In some cases, films that did only modestly in their theater releases went on to have strong performance in the rental market (e.g., cult films).

VHS has become the leading consumer VCR format after the "war", though its follow-ups S-VHS, W-VHS and D-VHS never caught up in popularity. In the late 1990s in the prerecorded video market, VHS began to be displaced by DVD. The DVD format had several advantages over VHS tape. A DVD disk is much better able to take repeated viewings than VHS tape, which can crack or break, which makes DVDs a better format from a rental store's perspective. As well, whereas a VHS tape can be erased if it is exposed to a magnetic field (such as by being left near a speaker), DVDs are not affected by magnetic fields. Even though DVDs do not have the problems of tapes, such as breakage of the tape or the cassette mechanism, DVDs can still be damaged by scratches. Another factor for movie rental stores is that DVDs are smaller and take less space to store. DVDs offer a number of advantages for the viewer: DVDs can support both standard 4x3 and widescreen 16x9 screen aspect ratios and DVDs can provide twice the video resolution than VHS. As well, a viewer who wants to skip ahead to the end of a movie can do so much quicker with a DVD than with a VHS tape (that has to be rewound). DVDs can have interactive menus, multiple language tracks, audio commentaries, Closed Captioning and subtitling (with the option of turning the subtitles on or off, or selecting subtitles in several languages). Moreover, a DVD can be played on a computer.

Due to these advantages, by the mid-2000s, DVDs were the dominant form of prerecorded video movies in both the rental film and new movie markets. In the late 1990s and early 2000s, though, consumers continued to use VCRs to record over-the-air TV shows, because consumers could not make home recordings onto DVD disks. This last barrier to DVD domination was broken in the late 2000s, with the advent of inexpensive DVD recorders and digital video recorders (DVR). DVR devices, which record shows onto a hard disk, can be purchased from electronics stores or rented from cable or satellite TV providers. Despite the mainstream dominance of DVD, VHS continues to have a role. The conversion to DVD has led to the marketplace being flooded with used VHS films, which are available at pawnshops and second-hand stores, typically for a cheaper price than the equivalent film on a used DVD. As well, due to the large number of VHS players in schools and libraries, VHS tapes are still produced for the educational market.

CAMCODERS

DV cassettes

Left to right: DVCAM-L, DVCPRO-M, DVC/MiniDV

Early consumer camcorders used full-size VHS or Betamax cassettes. Later models switched to more compact formats, designed explicitly for camcorder use, like VHS-C and Video8. VHS-C was a downsized version of VHS, using the same recording method and the same tape, but in a smaller cassette. It was possible to play VHS-C tapes in a regular VHS tape recorder by using an adaptor. After Super VHS had appeared, a corresponding compact version, Super VHS-C, was released as well. Video8 was an indirect descendant of Betamax, using narrower tape and a smaller cassette. Because of its intricate U-shaped tape loading and narrower tape, it was not possible to develop an adapter from Video8 to Betamax. Video8 was later replaced with Hi8, which provided better resolution and high-quality sound recording, and was similar to Super VHS-C.

The first consumer digital video recording format, introduced in 1995, used a smaller Digital Video Cassette (DVC).^[17] The format was later renamed MiniDV to reflect the DV encoding scheme, but the tapes still carry "DVC" mark. Some later formats like DVC Pro from Panasonic reflect the original name. The DVC/MiniDV format provided near-broadcast quality video and sophisticated nonlinear editing capability on consumer equipment. In 1999 Sony backported the DV recording scheme to 8-mm systems, creating Digital8. By using the same cassettes as Hi8, many Digital8 camcorders were able to play analog Video8/Hi8 recordings, preserving compatibility with already recorded analog tapes. As of 2008, Digital8 camcorders have been removed from the equipment offered by Sony.

Sony introduced another camcorder cassette format called MicroMV, but consumer interest was low due to the proprietary nature of the format and limited support for anything but low-end Windows video editors, and Sony shipped the last MicroMV unit in 2005. In the late 2000s, MiniDV and its high-definition cousin, HDV, are the two most popular consumer tape-based formats. The formats use different encoding methods, but the same cassette type. Since 2001, when MicroMV was presented, no new tape form factors have been introduced.

Future of tape

The latest trend in consumer camcorders shows the switch from tape-based to tapeless solutions, like built-in hard disk drives, optical discs and solid-state memory. In particular, Canon have not introduced a completely new HDV consumer camcorder for a third year in a row, confining itself to minor modifications to the 2007 model. Sony and Panasonic have removed their consumer tape-based camcorders from the North American market completely. In professional video recording settings, such as broadcast television, videotape was still heavily used in the mid- to late 2000s, but tapeless formats like DVCPRO P2, XDCAM and AVCHD, are gaining broader acceptance.