Held retained the firm's original name, and Carl's brother, Alfred Lorenz, was made the technical director.
Held then expanded into the telephone market in 1893, buying Lewart, and through this acquisition gaining a telephone-supplier position with the Postal Service.
[1] At the start of World War I, Lorenz had grown to about 3,000 employees and was a major supplier to the German military of land-line telephone and telegraph equipment and had also entered the wireless field.
For this expansion, a large factory was built in the Tempelhof district of Berlin, and by 1918, the headquarters and research operations also occupied this facility.
When World War I ended, Lorenz greatly decreased in size and turned to producing home radios, broadcast transmitters, and aircraft communications sets.
In 1919, Lorenz initiated radio broadcasting (transmitting voice and music) in Germany, and their first home receiver, the Liebhaber-Empfänger, was introduced in 1923.
After Held's death, the controlling stock became available and was eventually bought in 1930 by Standard Elektrizitätsgesellschaft, a subsidiary of the American corporation International Telephone and Telegraph (ITT); Lorenz as a firm, however, continued to operate independently.
Production of radio tubes for the German Army started in 1937 and was followed by the building of communication sets and similar electronics.
Ludwig Roselius of Kaffee Hag had contractual obligations with Lorenz and Sosthenes Behn of ITT Corporation.
[4] For wartime work, Lorenz, like many other German manufacturing firms, turned to inmates of Nazi-operated labor camps.
[11] Early in the development of radio, Lorenz scientist Otto Scheller invented a system composed of four antennas set in the corners of a large square and generating an array of overlapping, very narrow beams.
Called Ultrakurzwellen-Landefunkfeuer (LEF) or commonly, Lorenz beam, this system was sold worldwide for aircraft guidance and blind landing.
By 1939, Germany had installed X-Leitstrahlbake stations radiating into other countries, including Great Britain, but they did not raise suspicions since the signals were essentially the same as those from the standard Lorenz LEF system.
After an unsuccessful attempt to interest the German Navy, Müller's team turned to developing a system for supporting Flugzeugabwehrkanone (Flak, anti-aircraft guns).
In 1938, the Ordnance Office of the German Army gave Lorenz a contract to develop a prototype Flak-aiming set, code-named Kurfürst.
[15] In 1918, a German inventor developed a cipher machine using multiple rotors with pins representing alphabet letters.
The Enigma, however, had deficiencies, and the German Army High Command asked Lorenz to develop a new cipher machine that would allow communication by radio in extreme secrecy.
Unlike Enigma, no physical Lorenz machine reached Allies’ hands until the very end of the war in Europe.