Grünberger

Richard Grünberger operated in Vienna in the early Austrian radio-valve market. In 1926 the range included types I, II and III, a valve called Oszillator and two versions of the 201A output valve. The programme therefore combined proprietary names with an internationally used designation, which must be read alongside the manufacturer's marking.

Duplex-Mehrfach, with a special base, and B415 appeared later. Product development does not, however, establish a definite founding or closing year. 1926 dates the known range; the factory address and the duration of individual series are less precisely established. A Roman numeral or shared designation alone is insufficient to attribute a specimen to Grünberger.