In early 1920, technicians at a radio station [above] near Königs Wusterhausen, in northeast Germany, began experimenting with broadcasting live voice and music through an arc transmitter, which was used in early radio telegraphy to convert direct-current electricity into radio-frequency sine waves.
When the technicians broadcast a short introductory announcement on 22 December followed by a live instrumental concert to celebrate the upcoming Christmas holiday, it marked the first time speech and music were transmitted wirelessly. That concert is regarded as the birth of radio broadcasting in Germany.
The breakthrough was recognized last month with an IEEE Milestone. Administered by the IEEE History Center and supported by donors, the IEEE Milestone program recognizes outstanding technical developments around the world.
In January 1920, radio pioneer Hans Bredow supervised a group of the station’s technicians who were developing a way to transmit voice and music. They worked in cooperation with Telegraphentechnisches Reichsamt, a research center in Berlin that focused on telegraphy and telephony.
The team built a 5-kilowatt arc transmitter that operated at 111.1 kilohertz (wavelength 2700). The engineers upgraded the transmitter by adding a magnetic amplifier. A microphone connected to the transmitter could pick up speech and live music, as well as recordings of music played on a gramophone. Some of the radio station’s employees were also musicians, and their knowledge of acoustics helped improve the transmissions’ sound quality.
THE CHRISTMAS CONCERT
In December 1920 the technicians were so satisfied with the quality of their test transmissions they decided to broadcast a concert. The program began on 22 December with an announcer saying: “This is Königs Wusterhausen on wavelength 2700. As a sign that the station has attained full age and no longer serves as a guinea pig….” Then, for the first time in Germany’s history, the sounds of a violin, cello, and harmonium were broadcast live.
After the success of that first concert, more were scheduled. A radio station in Berlin transmitted a live performance of the opera Madame Butterfly. Technicians transmitted two-hour concerts from Königs Wusterhausen every Sunday night for the next six years.
A ceremony honoring the Christmas concert broadcast was held on 16 July at the Sender- und Funktechnikmuseum, in Königs Wusterhausen. A plaque mounted near the museum’s entrance reads:
In early 1920, in this building, technicians of the Königs Wusterhausen radio station, together with employees from the Telegraphentechnisches Reichsamt, began experiments broadcasting voice and music using an arc transmitter. By late 1920, tests had become successful enough to transmit an instrumental concert on 22 December—the so-called Christmas concert. This transmission is regarded as the birth of statutorily regulated broadcasting in Germany.