Milestones in the fifties
Danish circuits for Danish tv-viewers
DELTA plays an active role for the Danish television by developing a circuit to the television receivers which the Danish factories could use, and by constructing equipment to the big radio and television exhibition in Forum, which is described in the Danish TV-series "Krøniken" (the Chronicle).
Prototype from the 1950s. It was developed by ElektronikCentralen to show Denmark's radio industry that it had become possible to build radios using transistors and a battery instead of vacuum tubes, thereby making the transistor radio portable. As vacuum tubes required a voltage of about 70 V, they could not be powered by a battery.
Tape recorder, headset and microphone from the 1950s. They were used for the Danish Acoustical Laboratory's measurements. The small box is a noise calibrator from around 1960 and was used as a source of noise for calibrating a microphone. The noise was generated by small steel bearings dropping onto a mica membrane.