The German company Siemens was founded in 1847 as Telegraphen-Bau-Anstalt Siemens & Halske and was in the early days of radio already active in the construction of transmitters, receivers and also valves. Radio production came to a standstill with the destruction of the Siemens plants in Berlin and Arnstadt during World War II.
After the end of the Second World War, Siemens resumed its own receiver production and supplied the German navy with powerful receivers. The E 309a was followed in 1961 by the E 310a, the heavyweight receiver made it's name as rainbow receiver, on the large arc-shaped dial, the different ranges were coloured and were activated with correspondingly coloured keys. In parallel, the E 311 was offered from 1959 onwards, the triple conversion set with its mechanical digital display was SSB-capable. Other receivers were sold in a joined venture with Rohde & Schwarz, such as the E401 / 403 with it's digital frequency display using nixie tubes; the maritime communications receiver E410 in solid state technology was available with decadic switch frequency setting and with a conventional tuning mechanism and a mechanical digital frequency display. A final highlight was the CHR-531