2N1765

Vintage Western Electric PNP small-signal germanium transistor housed in a signature black cylindrical metal casing, engineered with gold-plated leads for early low-frequency voltage amplification, pulse generation, and Bell System telecommunication network laboratory R&D. Equivalents: 2N239A (closely related structural variant), NTE102A. Real-Life Examples: Legacy telephone central office research chassis, early post-war experimental analog computing circuits, and mid-century lab signal transmitters. [1]