IBM transistor replacements

Brent Hilpert bhilpert at
Sat Nov 27 16:53:58 CST 2021

On 2021-Nov-27, at 11:22 AM, Gregory Beat via cctalk wrote:
> The Texas Instruments (TI) 139 is likely a 2N139 PNP (BJT) transistor, 
> capable of high speed switching (in that era).
> The 2N139 was originally an RCA transistor (tall cylinder) found in RCA and GE transistor radios (455 kHz IF section).
> The TI versions were low profile metal case, TO-33 case (8.5 to 9.5mm diameter)

From the JEDEC number, 2N139 would be a 50s-era transistor, way earlier than the ones at issue.
2N139 specs are Ge-PNP, 16V/12V CE max, 15mA IC max, 35mW max, which can find a use in transistor radios, but highly unlikely to be what the OP is looking for.

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