Project type: video reel-to-reel

2” quad was a popular broadcast analogue video tape format whose halcyon period ran from the late 1950s to the 1970s. The first quad videotape recorder made by AMPEX in 1956 cost a modest $45,000 (that’s c.£325,880 in today’s money).

2” quad revolutionised TV broadcasting which previously had been reliant on film-based formats, known in the industry as ‘kinescope‘ recordings. Kinescope film required significant amounts of skilled labour as well as time to develop, and within the USA, which has six different time zones, it was difficult to transport the film in a timely fashion to ensure broadcasts were aired on schedule.

To counter these problems, broadcasters sought to develop magnetic recording methods, that had proved so successful for audio, for use in the television industry.

The first experiments directly adapted the longitudinal recording method used to record analogue audio. This however was not successful because video recordings require more bandwidth than audio. Recording a video signal with stationary tape heads (as they are in the longitudinal method), meant that the tape had to be recorded at a very high speed in order accommodate sufficient bandwidth to reproduce a good quality video image. A lot of tape was used!

Ampex, who at the time owned the trademark marketing name for ‘videotape’, then developed a method where the tape heads moved quickly across the tape, rather than the other way round. On the 2” quad machine, four magnetic record/reproduce heads are mounted on a headwheel spinning transversely (width-wise) across the tape, striking the tape at a 90° angle. The recording method was not without problems because, the Toshiba Science Museum write, it ‘combined the signal segments from these four heads into a single video image’ which meant that ‘some colour distortion arose from the characteristics of the individual heads, and joints were visible between signal segments.’

Ampex VR 5103 - A Format / PAL

Sony BVH 2000 x 2 - C Format / PAL & SECAM

Sony BVH 2000 - C Format / NTSC

Sony BVH 3100 P x 2 - C Format / PAL & SECAM

Scroll to the right to view full table on smaller screens.

One inch open reel video tape is especially susceptible to risks associated with age, hardware, and equipment obsolescence. It is also prone to risks common to other types of magnetic media, such as mould growth, binder deterioration, physical damage, and signal drop-outs.

A significant problem for the transfer of 1 inch type A, type B and type C tape, is the rarity of machines capable of playing these formats. Their considerable weight (70 - 80 kg) made 1" video machines more difficult to transport and preserve than subsequent, smaller cassette-based machines.

Our 1" machines are arguably some of the more complex electro-mechanical machines we have at Greatbear, when compared with other professional broadcast formats.To fully recalibrate a 1 inch type C machine, for example, can take a few days because of its size and complexity.

Recalibration is complicated by machines having multiple components which all need to be aligned in a very careful way for the best quality transfer – it is not a simple case of adjusting the machine as a whole and everything works fine. Each separate transport mechanism requires attention. This is then checked against the other parts to ensure that the machine operates, and after that, the electronics. The recalibration process is complete when a machine plays back the tape in such a way that reflects the quality of the recording, rather inconsistencies in the machine.

Another major threat to the future of such analogue transfers is that the highly-skilled people who know how to maintain and fix these machines are disappearing, as are the spare parts needed to do so.

1 inch video tape brands / models

Common brands / models of 1 inch video tape include: 3M/Scotch 480; 3M/Scotch 480 XST; Ampex 196; BASF VT26; Fuji H621; Fuji H261E; Kodak EVT-1000; Sony V-16 SP and Sony V1-K.

The Ampex Corporation introduced 1” (SMPTE) type A videotape in 1965. It was one of the first standardised helical scan open reel video tape formats in the 1” width. It was mainly used in industrial and institutional contexts because it did not conform to existing broadcast standards.

A significant problem was that the type A system did not record the vertical blanking interval, i.e. the time between the end of the final line of a frame or field and the beginning of the first line of the next frame. It was also restricted to 350 lines, while the NTSC standard was 525 and PAL / SECAM were 625 lines. The compromised quality of type A video led ultimately to the development by Ampex & Sony of the SMPTE approved type C format in 1976.

Despite being a composite video format like U-matic or VHS, (where video information is encoded on one channel), 1 inch type C has very high video quality. It approaches the quality of component video formats (where the video signal has been split into two or more component channels), as used in Betacam videotapes and the Panasonic MII.

The quality and reliability of 1 inch type C made it a mainstay in television and video production in television studios for almost 20 years, before being supplanted by more compact videocassette formats like Betacam, DVCAM, D-1, D-2 and DVCPro.

Introduced by Sony (1965), the CV-2000 series were among the earliest video tape recorders. They utilised ½" wide video tape on open reels, with tape being threaded manually around the helical scan video head drum., They were the first fully-transistorised VTRs

The Portapak system arrived in 1967, with the Sony DV-2400 Video Rover: a two-piece battery-powered set, consisting of a black-and-white composite video camera and a separate record-only helical scan ½" portable video tape recorder. It required a Sony CV series VTR (such as the CV-2000) to play back the video.

CV-2000 series machines lacked the capacity for tracking adjustment - meaning tapes were not easily interchangeable between different machines.

In 1969 EIAJ (Electronic Industries Association of Japan) developed standardisation for ½" video tape, which became the norm for many manufacturers, including Sony with their AV series machines (which included tracking adjustability).

The EIAJ standard widened the adoptability of ½" video tape, and as machines became more affordable, the format became popular  the early 1970s for non-broadcast use by businesses, schools, government agencies, hospitals, artists and even some home-consumers.

Portapak became a term for a variety of two-piece camera-plus-recorder systems manufactured by Sony, JVC and others, prior to the advent of camcorders.

½" video tape was superseded by easier-to-use cassette-based formats, such as Sony’s U-matic (1971).

• Akai VT 110
• Akai VT 120

Akai 1/4" Video Reel tape types  you might come across:

• Akai VT-5
• BASF FV 26R Videoband
• BASF FV 26AE Videoband

The Akai 1/4" video format is one of the most threatened formats for several reasons.

• The VT100, 110 range of VTR's were never as common as the 1/2" CV2100 and EIAJ range of Sony VTR's. As a result there are less available spare machines now, around 50 years later.
• The reduced width of tape the Akai VT range of machines used meant they are much smaller and lighter. An advantage for portability but this makes them tricky to work on and not very reliable long term.
• The head tips are small and extremely fragile on this format too. Of the 6+ Akai VT machines we have half have one broken head tip from either wear or more likely previous rough head cleaning attempts.
• The use of 1/4" tape often meant audio tape was used but the much rougher surface finish of audio 1/4" tape would wear the head tips very quicky. Specially made variations of Akai, BASF and Scotch tape were the only recommended tapes for this format.

In 1967, Akai introduced the first (and only) portable open reel video recorders that used ¼" tape. It was the lightest-weight of the all the portable video recording systems, and had a detachable monitor.

Aimed at a domestic market, the narrow width of the tape (all other portable video recorders of the era used ½ inch tape), reduced the quality of the output. It is a rarely-seen format.

See the Akai VT-100 reviewed in Radical Software Vol 1. Nr 3.