Tefifon

from Wikipedia, the free encyclopedia
Tefifon lettering on a device
Tefifon portable radio with sound tape cassette

The Tefifon was manufactured between 1950 and 1965 as a playback device for a special type of electromechanical sound carrier , the sound tapes. These were cassettes with an endless plastic tape, in which the sound signals were engraved in spiral grooves, similar to a record , and read by a scanning needle . On a Tefifon cassette there was space for up to four hours of music, so the sound tapes mostly contained compositions of hits or dance music as well as operas and operettas.

history

Teficord - rare predecessor of the Tefifons from the 1930s for loose sound bands

The Tefifon was invented by the German entrepreneur Karl Daniel . As early as the 1930s, tape recorders were produced for special, predominantly military purposes, with voice recording being the focus at that time. There was a device for recording and playback under the name Tefiphon (sic!) And a pure playback device under the name Teficord . Both used loose sound bands. A device for cassettes was first developed during the war. These were initially made of metal.

The first Tefifon players and sound tape cassettes for home use were presented at the radio exhibition in Düsseldorf in August 1950 , but could hardly prevail over records and magnetic tape . One reason was that all known artists were exclusively committed to record companies, but the record companies were not interested in offering Tefifon tapes. Thus only relatively unknown artists were presented on Tefifon tapes. In addition, there was an alternative with the record changer, with which one could listen to music for up to three hours almost without interruption (double-sided playing of ten long-playing records with a diameter of 25 cm, which, in contrast to the 30 cm LPs, were suitable for changers).

The Tefifon was offered in the 1950s as a stand-alone device, but also in combination with various types of radios, from music chests to case devices. The chassis of the radio sets were often bought in from outside companies and not developed in-house. The sound quality was superior to the shellac records that were still in use at the time , but did not quite match the quality of the vinyl records already available at the same time . In addition, the mechanical stress on the tapes during playback (stretching) was very high, so that they wore out relatively quickly.

As the last innovation, stereo devices and sound tapes were also offered from 1961 , but these did not catch on. Tefifon production in the main factory in Porz am Rhein (since 1975 Cologne-Porz) was discontinued in 1965. The rights to the name were taken over by the Neckermann mail order company, which also took over the sale of the remaining stock.

Sound tape

The original belt speed was 45.6 cm / s with a distance of 4 grooves per millimeter. The first sound tapes were inserted as such, later a cassette was built in which the sound tape was firmly inserted and also remained during playback. The sound grooves ran parallel to the sides of the sound tape because this was easier to manufacture than embossing the sound grooves in the form of a precisely running helical line. Instead of the helical line, the pickup was moved in three places by small lateral offsets. The red tape shown in the picture was only moved at 19 cm / s from 1954 and had 6 grooves per millimeter with a 16 mm bandwidth, which means up to 4 hours of playing time in the normal cassette (45 × 135 × 157 mm³) and 1 hour of playing time in the small cassette (45 × 96 × 112 mm³) allowed.

Sound tapes were only played on one side, although early considerations were made to design and manufacture them as Möbius tapes in order to use their entire surface in endless operation. However, numerous practical problems that would have arisen at the junction prevented implementation.

  • Tefifon cassette with sound tape (red)

  • Small cassette from above

  • View of the tape slot, the sound tape is 16 mm wide.

  • Enlarged section (5 ×) with the grooves.

  • Tape guide during playback

literature

  • Herbert Jüttemann: The Tefifon . Freundlieb Verlag Historischer Technikliteratur, Herten 1995, ISBN 3-931651-00-2 .
  • Rüdiger Walz: From "dwarf" to massive and heavy. In: Funkgeschichte 246, August / September 2019, pp. 176–187.

Individual evidence

  1. ^ Herbert Jüttemann: The Tefifon . 1st edition. Verlag Historischer Technikliteratur FREUNDLIEB, Herten 1995, ISBN 3-931651-00-2 , 4th sound bands of the Tefi devices.
  2. ↑ Patent DE400399 : Device for the photographic recording of sounds and their reproduction. Published on August 6, 1924 , Applicant: Dr. Lee de Forest. ‌
  3. ↑ Patent DE722359 : Process for the production of endless interlaced sound recording tapes . Registered on November 16, 1937 , published on May 21, 1942 , applicant: Schallband Syndikat AG, Berlin-Charlottenburg, inventor: Hugo Westerkamp, ​​Cologne-Braunsfeld. ‌

Web links

Commons : Tefifon  - collection of pictures, videos and audio files