Nußbaumer, Otto, Graz 1904
Lender: Technisches Museum Wien
100 x 100 cm, ca. 20 kg
Radio inductor, radio transmitter (capacitor), coherer, two aerials

This device uses electrical waves to transmit sounds over a distance of 30 meters. The high-frequency short wave trains of the transmitter are primarily broadcast at twice the basic frequency of the sound transmitted, causing the membrane of the headphones of the receiver system to vibrate at the same frequency. Additional interpolated arc-overs generate the harmonics typical of the sound of musical instruments and hence wave trains if these harmonics – like the fundamental vibration – also produce sufficiently strong current fluctuations at the inductor input and thus additional arc-overs on the secondary side.