old Japanese transistor numbers...I'm stumped

[rutabaga bob]

Been Googling for clues as to the identity of some Japanese transistors I scavenged from an old Silvertone tabletop radio from the late '60s, without success.  All are metal can and have a squared-off style capital S above the number, which I assume is a logo.  Below the logo are just numbers...99101, 99103, and 99201.  On the bottom line there are a number and a letter, 7E, 8C, or 8F, followed by an H inside a circle (like our 'registered trademark' emblem).  After that it says JAPAN.  Anyone got info?    Thanks!        Larry

[R.G.]

Just as US companies did, Japanese companies ordered transistors tested to their own internal specifications, and marked with their internal part numbers. I believe that is what you have, so unless you get really lucky, finding what original type number they are is probably impossible. Test them, use them based on the tests.

[rutabaga bob]

Thanks, R.G.!  I suspected it might be something along those lines.  Do you think there's a chance they could be germanium, from 1968?

EDIT:  Did some simple tests...they are pnp.  Put a transistor with an hfe of 80 under a warm desk light for a while, rechecked, hfe 92.  Stuck it in the freezer for a couple of minutes, hfe 69.

[Mark Hammer]

I've probably mentioned it here before , but there used to be a HE-YYEEEWWWWWG semiconductor cross-reference book that had everything in it, including the "true identity" of house numbers.  It was well over 1000 pages in teeny print (whatever point-size sports box-scores and food ingredient-lists on packagaing are printed in) on onion-skin paper the last time I saw one in 1989 or so.  Lord only knows if such a thing exists any more, although I imagine most of us could probably do okay with a circa-1985 issue.

If the part number is original, I have a scanned copy of an older Japanese transistor manual with specs on just about any 2Sxxxx type you want.  It's a fairly hefty file (about 70meg) so I'm not going to post it.  Drop me a PM if you need more information about a specific part.

[rutabaga bob]

Thanks for the offer!