Transistor package colours

[japlytic]

Some Japanese manufacturers use green coloured encapsulation for PNP transistors, whereas NPN transistors are normally black (some older transistors had grey encapsulation).
The above mainly affects transistors in a TO-126 or larger package.

I have seen blue 2SD386A(Y) transistors from 1977 - what does the blue colouring of the encapsulation mean?

[PeteS in CA]

Re: Transistor package colours

Hmmm ... all the plastic package transistors I've seen were Model T-colored ("Any color you want as long as it's black"). W/O looking for a datasheet ... could it be a darlington or a JFET?

[budm]

Re: Transistor package colours

I have seen and used Japanese transistor with Green, red, blue casing on TO-220. I do not think it means anything since the same one manufaturer will use the color they want to differentiate it from other manufacturer even thoug it has the same P/N as the other manufacturers .

[kc8adu]

Re: Transistor package colours

i remember some nec 2sc1307 in red cases.
bought the bag of 500 at a surplus dealer.
i tested them and they had about 3db more gain than others i had seen.
these average about 12db.some of the red ones were 16.
special run for an oem?
this was when cb was hot.these are used in final stage of ssb cb's.