Akai ¼-inch open reel video tape (1969 – late 1970s)

Akai ¼-inch video tape was an analogue open reel video tape format introduced in 1969. It used helical-scanning and initially only recorded in black and white (a colour video recorder using the tape, the Akai VTS-150, was introduced in 1974).

The first machine to use the format was the Akai VTS-100, a portable video tape recorder with a detachable video monitor and a video camera. An optional RF modulator was available for playback through a standard television set.

Video resolution was 200 lines, and the system was aimed at the consumer market. One advantage over other domestic video tape recorders that used ½-inch wide tape (such as the EIAJ-1 ½-inch format) was that tape for the Akai system was much cheaper. A number of different companies produced tape for the Akai format.

Most of the tape was on plastic 5-inch reels with cine spindle hubs but the VT-700, a stationary video tape recorder introduced by Akai in the early 1970s, could accommodate 10.5-inch NAB hub reels of ¼-inch video tape as well.

Tapes recorded on the later colour VTS-150 are not compatible with tapes recorded on black and white models due to differences in tape speed.

Sources / Resources

Soundmirror (1948 – 1954)

Soundmirror tape (also known as ‘magic ribbon tape’) was a magnetic tape format for use on the Soundmirror tape recorder made by Thermionic Products in the United Kingdom. What was unusual about it was that was made of paper with an oxide coating rather than the standard plastic tape.

Thermionic introduced the Soundmirror tape recorder in late-1948 under licence from the Brush Development Company in the US, after introducing the Recordon dictation disc (also made of paper) earlier in the year. The Soundmirror machine became the first domestic tape recorder on the UK market.

While the Recordon disc was aimed at the dictation market, the Soundmirror format was aimed at longer duration recording such as concerts, meetings and lectures. The tape ran at 7.5 inches per second on a maximum reel size of 7-inches, so allowing up to around 30 minutes of recording.

Production of the Soundmirror continued until 1954 by which time acetate (and later polyester) had become the standard magnetic tape base material.

Sources / Resources

Scotch One Five Special (1960s)

The Scotch One Five Special was a 3-inch reel of ¼-inch magnetic recording tape produced by 3M that could be recorded and played back on a standard open reel tape recorder. Once recorded, the reel would be placed back in its packaging which had space on it to write an address and to attach postage stamps to send it to someone. The tape could record for 15 minutes (hence the name) when run at 3¾-inches per second.

Similar reels marketed for keeping in touch by posting voice recordings were available around the same time, such as the Mastertape Voice Letter and the EMI Voice Letter. The Smith Corona Mail Call Letterpack of the late 1960s was a similar concept. Postage overseas was much cheaper than making an international telephone call at the time.

The One Five Special does not seem to have become very popular, and would probably have been superseded by smaller and more convenient products like the Compact Cassette.

Sources / Resources

Mohawk Midgetape (1955 – early 1960s)

The Mohawk Midgetape was an early portable tape recorder introduced by Mohawk Business Machines in 1955 with the Midgetape 44 model.

It used a tape cassette in a metal casing with ¼-inch tape allowing 30 or 45 minutes of recording on each side of the tape. The cassette design is unusual in having the spools on top of each other (coaxial).

The is no fast forward, and rewinding is done with a fold-out handle. It came with a microphone, and had a headphone jack. Accessories included a separate amplifier, an adaptor for recording telephone conversations, a wristwatch microphone, and a leather bag with hidden microphone.

Later models were fully transistorised (the 44 had used subminiature valve tubes) and the final Midgetape model was the 500 Professional introduced in 1959. There was a also a machine based on the Midgetape called the Lafayette Transcoder that in 1961 claimed to be able to record conversation up to 30 feet away.

Sources / Resources

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.

Sources / Resources

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.

Sources / Resources

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.

Sources / Resources

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.

Sources / Resources

Philips EL 3581 (1958 – early 1960s)

The Philips EL 3581 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 3581 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 EL 3583 and Compact Cassette formats in 1963, followed by the mini-cassette in 1967 and it doesn’t appear the EL 3581 was produced for long.

Sources / Resources

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.

Sources / Resources