Protona GmbH, Hamburg 1951–1957
Lender: Vienna Museum of Technology
11,5 x 18 x 4,5 cm, ca. 1 kg
Plastic, wire spools, batteries, three earphone tubes (DF67)

The Minifon is a small battery-powered wire tape recorder with a number of accessories (various hand-held microphones, attachable microphone, earphones, spools, batteries etc.). The hairsbreadth wire (0.09 mm) allowed recordings with frequencies ranging from 150 Hz to 3.3 kHz. The small size and the limited electronic possibilities meant that the Miniphon could only be used as a dictation device, although one spool of wire could be used for up to 300 minutes of recording at a wire speed of 20 cm per sec.