Tefifon

thumb|Tefifon portable radio with cartridge player (the Tefi "Holiday Super II")The Tefifon is an audio playback format, developed and manufactured in Germany, that utilizes cartridges loaded with an endlessly looped reel of plastic tape. It is somewhat similar to the later 4-track and 8-track magnetic audio tape cartridges, but with grooves engraved into the tape, like a phonograph record. The grooves were engraved in a helical fashion across the width of the tape, in a manner similar to Dictaphone's Dictabelt format. The grooves are read with a stylus and amplified pickup in the player's tra