The project started in 1938, associating the Reichspost and several companies, including Bosch, Blaupunkt, Loewe, Lorenz, TeKaDe and Telefunken. The objective was to produce 10,000 units, but the start of World War II caused only about 50 devices to be installed in military hospitals and various government departments. The Berlin transmitter was destroyed by Allied bombing in November 1943.