2N706

Ubiquitous classic NPN silicon planar epitaxial small-signal transistor housed in a metal TO-18 can, purpose-built for ultra-high-speed digital logic switching arrays in early computing systems. Equivalents: 2N706A, BSX20, NTE123A. Real-Life Examples: Vintage computing logic core arrays, classic digital calculators, and early silicon-era amateur ham radio transmitter oscillators.