Al -
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)
greg
==
From: Al <alsilisk at icloud.com>
To: cctalk at
classiccmp.org
Subject: IBM transistor replacements
Dear all,
A while ago I received an IBM 3286 printer, annoyingly some of the transistors in the
printer section have been corroded.
What I am having trouble with is reading the part codes and finding a modern equivalent of
them.
One has a Ti logo and two sets of numbers (attached). Does anybody know which numbers are
the part numbers and if they are IBM house numbered?
Photos of the Ti transistors and card assembly:
https://drive.google.com/drive/folders/1JTnsWS4A8NrYJNFsqK2ejOeqqJNjoF1w?us…
Thanks in advance,
Al