USSR Germanium Transistors


The image shows a 'Top Hat' germanium transistor from the early 1960s.
The Soviet semiconductor industry started in 1947 with point contact germanium diodes for detectors in radar systems. These were based on German devices. The USSR further developed its industry through a combination of internal innovation and development, and reverse engineering of Western products. The transistor, a P422 was part of a series of high frequency devices. The manufacturer is unknown. It is sitting on a photo of the internals of a SELGA 7 transistor radio which was made in the Riga Radio Rupnica Factory in Latvia in the early 1960s. A similar transistor can be seen with an orange mark to the left, (artistic blurring to the photo :-).

This works - germanium PNP, hfe (gain) = 51, Vf=298mV.       

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