After
World War I, the
Marconi Company began producing non-industrial receivers, principally for the amateur market, at the
Soho premises of The Marconi Scientific Instrument Company. In 1922, the
Marconi Company formed the "Marconiphone" department, to design, manufacture and sell domestic receiving equipment. This equipment complied with Post Office specifications and tests, and was therefore awarded the
BBC authorisation stamp; initially sets were made at the
Chelmsford Works. In December 1923, the 'Marconiphone' department was formed as a subsidiary of the
Marconi Company. Some Marconiphone Company sets were made at the
Sterling Telephone Company (STC) Works at
Dagenham. However, design and research of these domestic receivers still continued at
Chelmsford. == Gramophone Company ==