DF 40 Wired Radio Receiver

Siemens & Halske AG, Berlin around 1939
Lender: Vienna Museum of Technology
Radio Receiver Siemens D40
32x 19 x 30 cm, ca. 5 kg
Wood, loudspeaker, signal amplifier, tube technology

Wired radio is the term used to describe any long wave, occasionally also medium wave transmission of information by means of modulated oscillations via electricity and telephone lines using the carrier frequency method. These transmissions can be received by inserting a frequency-separating filter between the line and the receiver.