IBM transistor replacements

William Donzelli wdonzelli at
Sat Nov 27 17:09:22 CST 2021

139 is a "nickname" number. IBM used these nicknames for some reason,
instead of the full IBM part number.

A 139 is really an IBM part number 2414938, a silicon device in a TO-18.

Gee, it would be great if this list could take pictures so I could
just post one with all the specs...


On Sat, Nov 27, 2021 at 5:54 PM Brent Hilpert via cctalk
<cctalk at> wrote:
> 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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