The TR-1 was the first transistor radio made in Germany after Texas Instruments introduced the technology to the market the year before with their Regency TR-1. Only a limited number of 100 Telefunken transistors were manufactured in a pilot run. They were not offered for sale, but distributed to a select group of individuals for testing. One OC604 and five OC602 transistors were built into the device. The radio in a plastic case could receive only medium wave. 6 circuits for AM