S1a-112 Wallphone

Telefonbau and Normalzeit Lehner & Co. T&N was founded in Frankfurt in 1899 as a telephone rental company. In the 1980s, it was renamed Telenorma. Until 1986, AEG-Telefunken AG was the largest shareholder in T&N. In 1987 the company became a full subsidiary of Robert Bosch GmbH and from the beginning of 1995 it initially operated as Bosch Telenorma and later as Bosch Telecom GmbH. The S1a-112 telephone was manufactured in three types: E1, E2 and E3. Types E1 and E2 date back to the early 1950s. It has a metal base with a thermoplastic shell-seat, but the handset is made of bakelite. The model is printed under code S1a-112 / 16V. The cords of the device when they are fabric and when they are braided type plastics. The electrical components are mounted on the metal base. The base is not painted but remains in the natural shade of steel. The model of the device, the year of production and the type are imprinted on it. In type E2 The handset cable is a knitted plastic covered cable. The code for this model is S1a-112 / 72I. The main difference here is that the handle is now made of plastic and not bakelite. Both type E1 and type E2 were produced in four shades: black, ivory, brown and gray-green. The E1 and E2 models were produced until the early 1960s. In the early 1960s T&N developed the E1 and E2 with the advent of the E3 type. This type was manufactured until the early 1970s. Construction and materials follow the same philosophy as the previous two types. The base is metal while the shell and the handset are made of thermoplastic material. The differences are obvious in the exterior design of the telephone device. This phone has a similar footprint but is slightly taller. The dial rotary and the handset have been changed and the braided cable of the headphone is replaced by a spiral type plastic. The code for this model is S1a-112 / S1. And here at the base the same information is imprinted as its predecessors. This device was only available in gray-green.  All of the above devices were promoted by companies selling and renting call centers. Not marketed for home use. In Greece, they are placed by OTE in all shades, with the rarest being coffee and ivory when placing telephone exchanges in Public Services, private companies and hotels from 1955 until the early 1970s.