Tagged: ¼ inch

Open reel instrumentation and data logging tape (1949 – 2000s)

Magnetic tape was first used for data logging and instrumentation recording in 1949, when Jack Mullins installed modified Ampex Model 300s at Point Mugu Naval Air Station and at Edwards Air Force Base, both in southern California.

Tape has been heavily used since then for military, industrial, government and research applications. The Inter-Range Instrumentation Group (IRIG) set the standards for instrumentation tape recorders.

Instrumentation recorders were built to much more stringent standards than other tape recorders, and recorders that used direct, FM and PCM recording have been available.

On ¼-inch wide tape, there are typically 4 tracks, whereas on ½-inch tape there were 7, or sometimes even 14, tracks. On 1-inch tape, there were 14 or 28 tracks. Tape is usually wound on the reel with the recording surface facing towards the hub (the opposite of audio tape). Metal NAB reels were often used, for reels between 10.5 and 16-inches, but 7-inch plastic reels with cine spindle hubs have also been used.

Instrumentation recorders also used tape in cassette form, including systems that recorded onto S-VHS tape, and the Digital Instrumentation Recorder from Sony that used the SD1 cassette.

Instrumentation and data logging systems now use hard disks or flash memory for storage.

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Grundig Stenorette (1954 – 1970s)

The Stenorette was an office dictation machine introduced by Grundig in 1954, and successfully sold internationally. It was perhaps the earliest magnetic tape dictation system – at the time of its introduction, most office dictation systems were using discs or belts onto which grooves were pressed, such as the SoundScriber, Audograph, or Dictabelt systems. The first model, the Stenorette A, was nicknamed the ‘tree frog’ due to its green colour. Like some other dictation systems, the microphone doubled as the speaker, and contained stop/start controls.

The Stenorette cassette contained a single reel of ¼-inch tape, and a loop on the end was pulled out and clipped into the take-up reel. Recording time was 30 minutes per cassette, but some offered 45 minutes. Some tapes, particularly those from the US, seem to have no cover and are simply a small reel.

The Stenorette cassette system lasted into the 1970s with the introduction of the Stenorette SL model in 1972, but Grundig launched its first machine using its new cassette format, the Steno-Cassette in the same year. The Steno-Cassette was a true cassette containing dual reels and as well as being more compact, didn’t need to be rewound before being removed from the machine. The Stenorette name was continued on machines using the newer Steno-Cassette format.

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DASH (Digital Audio Stationary Head) (1982 – mid-1990s)

Sony introduced the DASH (Digital Audio Stationary Head) in 1982 for use in professional recording studios. The DASH system could record two-channel audio on ¼-inch tape, or 24 or 48 tracks onto ½-inch tape, and DASH recorders were produced by Sony, Studer and TASCAM.

The tape itself looked identical to standard NAB open reel analogue tape, but tape for use in DASH and the competing (and incompatible) ProDigi format systems used metal-particle tape which was not suitable for use in analogue systems due to the faster wear on the heads. Several companies produced open reel metal-particle tape for digital audio systems, and some examples included 3M Scotch 275, Ampex 467, EMTEC 931 and Sony own-brand tape. Metal-particle tape was even more expensive than oxide-based tape for analogue systems.

Unlike some other digital audio recording systems using tape such as DAT or U-Matic which used helical scanning, the DASH and ProDigi systems used a stationary recording head.

The audio was encoded as PCM, and included error correction, and all DASH recorders were capable of using 16-bit resolution with a 44.1 or 48 kHz sampling rate, with a couple of models capable of 24-bit 48 kHz operation.

DASH and ProDigi were the two main open-reel digital audio recording systems in use from the early-1980s to the mid-1990s, but eventually the falling price of hard-disk space, as well as more compact systems such as ADAT, made them less viable.

Although DASH was a digital system, it still had the disadvantage of having to wind through the tape to find a particular point, and wear could still be a problem. Poorly maintained machines or tape, dust, or fingerprints could render tapes unusable despite the error correction system.

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Preservation / Migration

media stability 5obsolescence 5

Dictaphone Dictet (1957 – early 1960s)

The Dictaphone Dictet was a portable dictation device introduced by the Dictaphone Corporation in 1957. It was perhaps the earliest portable magnetic tape dictation system – the Grundig Stenorette was an office dictation system using tape, introduced in 1954. An earlier portable system, the Protona Minifon used wire recording.

The Dictet was fully transistorised and weighed 1.2kg. The cassette had a metal shell and could record up to 60 minutes (30 minutes per side) on ¼-inch tape that ran at 2½ inches per second. Using special mercury batteries, the Dictet could operate for 20 hours.

The Dictet lasted until at least 1962, but it is unclear how much longer it lasted against newer competitors such as the Compact Cassette of 1963.

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Philips EL 3581 (1958 – early 1960s)

The Philips EL 3851 was an office dictation machine introduced by Philips (known as Norelco in the US) in 1958 and was one of the earliest magnetic tape dictation systems (the Dictaphone Dictet was launched shortly before it). At the time of its introduction, most dictation systems were using discs or belts onto which grooves were pressed, such as the Dictabelt, SoundScriber and Audograph systems.

Although the EL 3851 uses a cartridge so no threading is required, the tape is housed on two separate 3-inch reels with ¼-inch tape and cine spindle holes suitable for domestic open reel tape recorders. Removing a clip from the cartridge shell allows the reels to be removed.

Like some other dictation machines, the microphone also doubles as a speaker, and contains some tape controls. A foot pedal and external speaker were also available.

Philips later introduced the much smaller Compact Cassette format in 1963, followed by the mini-cassette in 1967 and it doesn’t appear the EL 3851 was produced for long.

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HDV (2003 – 2011)

HDV was a high-definition digital video format for camcorders. Because of its high quality, it has been used for broadcast television as well as amateur video recording. JVC was the first company to release a HDV camcorder in 2003, with Sony and Canon producing camcorders later.

HDV video can be recorded at 720p and 1080p, sometimes referred to as HDV1 and HDV2 respectively.

Although special HDV tapes are available, their use was not required as the tape formulation (Metal Evaporate) is the same as standard MiniDV cassettes. One Sony camera could also use the large DV cassette format. HDV devices could usually play and record in DV format as well as HDV.

Accessories were available to allow HDV camcorders to record to non-tape media such as CompactFlash cards.

By 2011, Canon, JVC and Sony had discontinued their HDV products, and invested instead in fully tapeless formats such as XDCAM.

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3M Cantata 700 (1965 – 1990s)

The 3M Cantata 700 was a background music system introduced by 3M in 1965.

The tape cartridge was the largest ever available and consisted of two 8-inch open reels of ¼-inch mono tape stacked on top of each other. Each cartridge could hold up to 700 songs, hence the name of the system.

The 3M Cantata system could be used for locations such as shops, offices and restaurants, and the pre-recorded music was licensed for public performance (it wasn’t possible for the user to record onto the system). It was used into the early 1990s.

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Stereo-Pak 4-Track Cartridge (1962 – 1970)

The Stereo-Pak 4-track cartridge was the forerunner to 8-track cartridges. It was based on the Fidelipac cartridge, the industry standard tape cartridge used at the time for radio broadcasting of commercials and jingles, but used 4 tracks to provide 2 stereo programmes.

It was introduced in 1962 by Earl ‘Madman’ Muntz (a merchandiser of used cars and consumer electronics). Players were usually fitted to cars (including those of a number of celebrities) but home players were also available, and these were capable of using the larger cartridges based on B and C size Fidelipac cartridges.  The Stereo-Pak system lasted until around 1970, by which time 8-Track was more popular despite being of poorer quality.

Muntz licensed music by many popular artists from most of the major record labels, and released hundreds of titles in many genres. Columbia Records was one of the few major record labels to release music recorded on Stereo-Pak cartridges themselves on a widespread basis.

The tape is arranged in an infinite loop which traverses a central hub and crosses a tape head at 3¾ inches per second, pulled by tension. The tape is dampened by a lubricant on the back, usually graphite. A lever on the player allowed the switching between programmes. Due to the method the tape is moved, it is impossible to rewind, and often risky to fast forward a 4-track tape.

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Fidelipac (1959 – late 1990s)


Fidelipac (commonly known as an NAB cartridge) was a magnetic tape cartridge format, used in radio broadcasting for playback of material such as radio commercials or jingles. It was the first audio tape cartridge commercially available when it was introduced in 1959 by Collins Radio.

Fidelipac used ¼-inch endless loop tape, with two or three tracks one of which was used to cue the tape. Most players ran at 7.5 inches per second, though some could also run at 3.75 or 15 ips.

There were three sizes of Fidelipac available; the 4-inch wide A size (up to 10.5 minutes playing time), the 6-inch wide B size, and the 8-inch wide C size. The most commonly used for broadcasting purposes was the A size, and the B and C sizes were usually used for background music applications where the tape speed usually was 3.75 inches per second for longer playing times.

Fidelipac was adapted as the basis for the 4-Track Stereo-Pak cartridge. Other similar cartridge designs were later used in broadcasting, such as the Audiopak and Scotchcart.

Unlike the 8-Track cartridge (but like the 4-Track cartridge), the pinch roller was built into the player and swung into place through a hole in the cartridge.

Fidelipac was widely used at radio stations until the late 1990s, when such formats as MiniDisc and computerized broadcast automation made it obsolete.

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DVCAM (1996 – )

DVCAM is a variation of the DV format introduced by Sony in 1996, and aimed at the semi-professional and lower-end professional market.

DVCAM uses the same type of tape and compression as DV and MiniDV but at a higher speed (almost 50% faster). In common with all DV formats, DVCAM uses tape that is ¼-inch (6.35 mm) wide. DVCAM uses metal evaporated (ME) tape

DVCAM tapes come in two different sizes. The smaller size uses the same form-factor as MiniDV and can hold up to 40 minutes, which the larger size (which is actually the medium size DV tape) can hold up to 184 minutes.

Technically, any DV cassette can record any variant of DV video.

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Preservation / Migration