Cassette recorder

from Wikipedia, the free encyclopedia
One of the first Philips cassette recorders from 1963 with the typical one-button operation
type EL 3302 (battery operation)
Cassette recorder for data storage manufactured by VEB Elektronik Gera
Drives
Drive mechanics
Drive the drive
Slot-in autoreverse playback drive of a car radio with two sound waves (without erase head)
Autoreverse drive of a car radio with two pulleys and small flywheels on the capstan
The high-end cassette deck Nakamichi Dragon had a calibration computer for the tape properties, rear tape control and automatic azimuth adjustment . The price was around 4,000 DM.

Cassette recorders are a special form of audio recorders in which the sound is recorded analog on compact cassettes . They are a small variant of tape recorders that became popular in the 1970s . The compact cassette, also known as audio cassette, was presented by Philips in 1963 at the international radio exhibition in West Berlin and launched on the market.

With the triumph of digital sound recording  - especially the MP3 format as a medium for private music collections - the importance of cassette recorders steadily decreased from around the end of the 1990s. Only a few cassette recorders are now available in stores.

Types of tape recorders

Cassette recorders come in a variety of combinations and types:

  • as a mostly portable single device with loudspeaker and built-in microphone
  • as a dictation machine with microphone and additional functions, also for mini or micro cassettes with reduced tape speed (2.4 cm / s or 1.2 cm / s); Such devices could often be stopped and restarted by a switch attached to the microphone
  • as a cassette deck without its own amplifier
    • in a hi-fi tower ("tape deck") or
    • as part of a midi mini, micro stereo or compact system
  • as a radio recorder with built-in radio receiver
  • as a combination with a clock radio (often without a recording function)
  • as a portable small device z. B. Sony Walkman - mostly only cassette player (player) without recording function (some with built-in radio receiver)
  • as a player in the car radio

Until the late 1960s into it you could see the commercial prerecorded Musicassette only on so-called Cassettophonen play without recording function.

The first home computers (e.g. Sinclair ZX80 ) began using cassette recorders for data storage from the late 1970s (see also Datasette ). The data or programs were converted into audible tones using a manufacturer-specific process so that they could be recorded using analog technology, and digitized again when they were read in again. The data rate achieved in this way was typically around 150 ... 300 bit / s, which was sufficient for the small amounts of data.

Standard equipment elements

  • Playback: Play the recording
  • Recording: Record with deletion of the previous recording on the tape. A recording can be prevented by breaking out the erasure protection tabs on the upper edge of the cassette for each page individually.
  • ⏪ Rewind: Fast rewinding of the tape onto the supply reel without sound reproduction
  • ⏩ Forward: Fast rewinding of the tape onto the take-up reel without sound reproduction
  • Stop: Lifting the pressure roller and mostly also the tape head from the tape, switching off the drive
  • Break: only lifting the pressure roller and disengaging the winding mandrel - the drive is running properly. d. R. continue and the tape heads remain in place. The level display is still active when recording .
  • Eject or eject button to open the cassette compartment
  • Auto-stop system (automatic switch-off of the belt drive at the end of the belt). With simple drives, there is a pen on the tape between the tape head and the erase head, which monitors the tape tension. If the tape tightens, the pen triggers the stop. With more complex drives, either the rotation of the winding mandrels is monitored or the entry of the transparent pre-strip at the beginning / end of the cassette is scanned with a light barrier. If the winding mandrel is monitored, this also protects against tape salad .
  • Input and output sockets
  • Headphone output
  • Level indicator
  • Level control or automatic level control
  • Fe / Cr switch (tape selector switch) or automatic tape type selection
  • Interrogation of the protective flaps on the upper side of the cassette

Other controls

Depending on the intended use, price range and era, you will find additional elements and features.

  • Input selector switch between microphone, DIN or Cinch socket. This has become unusual since DIN cables are no longer in use and microphones are no longer installed.
  • Tape counter, for simple drives as a mechanical counter; with complex drives digitally, sometimes even in minutes / seconds, sometimes with remaining time display
  • Built-in microphone (not on cassette decks)
  • Record timer, the recording by time switching requires additional technology with electronic buttons, with mechanical buttons it is sufficient to press them and operate the device on a timer.
  • Adjustable headphone output
  • Built-in radio receiver
  • stereophony
  • Style recording (REC MUTE): Automatic insertion of a pause in the recording, e.g. B. can use an automatic search (for example the Automatic Program Search System from Sharp ) to find titles
  • Automatic search that requires pauses between recordings
  • Auto reverse system (automatic page change at the end of the tape)
  • Auto-Repeat (automatic rewind at the end of the tape, restart at the beginning of the tape)
  • Rear tape control through an additional tape head
  • Adjustable pre-magnetization (BIAS)
  • Noise suppression system , e.g. B. Dolby , High Com , DNL or dbx
  • Illuminated cassette compartment
  • Changeover switch for metal bands
  • CD dubbing (automatic CD recording)

Cassette deck

The cassette deck or tape deck is a sound source with compact cassettes and was part of a stereo system in the 1970s to 1990s, mostly in addition to a record player and a radio part. The cassette deck was either a separate device in a hi-fi tower, or later integrated into a compact system.

Due to the size, a significantly higher quality construction is possible compared to the compact cassette recorder. Above all, the controlled belt drive, the large centrifugal masses and the precise belt guidance result in an even belt speed. A constant tape speed is a prerequisite for accurate pitch playback. High quality cassette decks are often equipped with a dual capstan drive . The tape is tensioned with two drive elements, one in front of and one behind the tape head and the contact pressure is precisely controlled. The electronics are also more complex and offer (possibly several) options for noise suppression, a filter to suppress the pilot tone during VHF recordings ("MPX filter") and the optimization of the recording parameters (premagnetization) for the tape used (" Calibrate ”), even fully automatic in high-end devices.

A second tape head was installed in high-quality recording devices for monitoring the rear tape. Directly behind the first tape head with which the recording is made, there is another tape head with which the signal that has just been recorded can be played back, so that the recording result can be checked immediately.

Devices with two cartridge drives are used to copy cartridges. Some devices had the function of high speed dubbing , whereby the copying time was reduced by increasing the tape speed of both drives. Although similar processes were and are standard in the industrial mass production of prerecorded audio cassettes with copier machines, high-speed dubbing with home devices was not convincing in terms of quality. In 1985, an exotic radio recorder came on the market with three cassette drives, two of which could record. The three cassette drives were driven by two motors, one of which drove two drives. Cheaper double decks only had one motor, which canceled out fluctuations in speed and synchronization during high speed dubbing , which was common with portable devices.

See also

literature

  • Helmut Röder, Heinz Ruckriegel, Heinz Häberle: Electronics 3rd part, communications electronics. 5th edition, Verlag Europa-Lehrmittel, Wuppertal 1980, ISBN 3-8085-3225-4 .
  • Gustav Büscher, A. Wiegemann: Little ABC of electroacoustics. 6th edition, Franzis Verlag, Munich 1972, ISBN 3-7723-0296-3 .

Web links

Commons : Tape Decks  - collection of images, videos and audio files
Commons : Compact Cassette Drives  - collection of pictures, videos and audio files
Commons : Drive mechanisms  - collection of pictures, videos and audio files
Wiktionary: Cassette recorder  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. https://books.google.de/books?id=wTjUDgAAQBAJ&pg=PA174
  2. https://www.youtube.com/watch?v=HOpwCSB3kxs