OB Stadtfernsprecher Modell 1904

The city telephone, (Stadtfernsprecher Stf M1904) or as an office telephone, (Pultfernsprecher M1904) is a wall-mounted device made entirely of wood. It appeared at the beginning of the 20th century, specifically in 1904 as an order from the German Imperial Telegraph Administration, (Reichs-Telegraphen-Verwaltung or RTV) for its modernization. The device was operated by a local battery, (OB – Ortsbetrieb) since automatic telephone exchanges were not yet widespread in Germany, this device was based on a manual operating system. The user had to forcefully turn a hand crank to generate electricity, alerting a local operator at the telephone exchange to route their call. The telephone, designed as a slanted desk shape (Pultform) allowing users to take notes during calls, was made of walnut with a hinged desk top. It incorporated a hand crank generator (Kurbelinduktor) for signaling the call. This system consisted of an internal three-way crank inductor connected to a protruding external double bell (Doppelglocke) on the upper front for the notification of incoming calls and a carbon grain microphone (Kohlekörner-Mikrophon) which was equipped with a movable metal arm which allowed it to be positioned according to the height of the user. Next to it was the receiver, a separate spoon-shaped hand-held handset (löffelförmiger Hörer) suspended from a brass switch with a hook (so-called fork) on the side of the unit. Its dimensions are H: 50 cm, W: 33 cm, D: 23 ​​cm, and its weight is 6,500 g. The main manufacturers involved in the production of the M1904 were several leading electrical companies of the time under imperial contract, such as Siemens & Halske, F. Schuchardt, Mix & Genest and Deutsche Telephon und Telegraphen werke AG R. Stock & Co. Gmbh, (later known as DETEWE). In our collection we have a wonderful antique wall telephone from the company R. KRÜGER BERLIN.