Greg, Thank you, I will see if I can find a modern day equivalent of that and compare them, always useful to have spares on hand.
Thanks, Al (Also, apologies for the hideous formatting on my last email, something got very broken somewhere) > On 27 Nov 2021, at 21:00, Gregory Beat via cctalk <cctalk@classiccmp.org> > wrote: > > 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 <alsil...@icloud.com> > To: cctalk@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?usp=sharing > > Thanks in advance, > Al
