1903 To prevent the English Marconi Company from having a monopoly on wireless transmissions,,Kaiser Wilhelm II orders the company AEG and Siemens to set up a joint venture to develop wireless telegraphy in Germany. It was established under the name of Gesellschaft für drahtlose Telegrafen mbH.

1923 The company name is changed to Firmierung in Telefunken, Gesellschaft für drahtlose Telegrafen mbH. Abbreviated as Telefunken, where Tele means Telegraph and Funken means "Lightning" in the sense of being fast and immediate.

1930 Production gradually moves from military and Government equipment to the production of consumer appliances. During this period, Telefunken enters the market of radio-television, recorders and etching of records.

1930 As radio transmissions are now needed not only to transmit telegraph messages, but also true music and speech broadcasts, it becomes necessary to introduce the concept of sound compression, to avoid continual volume level changes of the radio. Telefunken designs and produces the U3, the first compressor for transmitting stations in the world,. TheU73b, as seen in the picture, represents the evolution of previous models—it allows you to change the compression level, the release times and the attack times.