After World War II, in March 1946, the Tesla company was founded as a successor to the electrical engineering company Elektra, which until then belonged to the Philips company. In August 1946, the Tesla national company was founded, which included, among others, other companies producing telephones, exchanges and other equipment, such as Telegrafia, Siemens-Halske, Prchal-Ericsson, Mikrofona or Elektrotechna. The national company was founded on August 10, 1946 at the Mikrofona factory in Prague Strasnice. The first models of telephones and equipment under the Tesla brand had only the TESLA logo printed or embossed on them, but they were devices that had been manufactured in individual units until then. However, in the national company, the production of individual equipment and components is gradually being grouped. The post-war base for the production of telephone equipment (telephones, equipment and exchanges) is the Tesla Karlin factory (until then Elektrotechna, Siemens & Halske) and the Tesla Kolin factory (until then Prchal-Ericsson). The transmission systems were manufactured in Tesla Strasnice (until then Mikrofona, Bratri Knotkove).