Does anyone have info on this transistor?

[Wild E]

I found it in a bin marked "germanium audio transistors" at my local surplus store. I guess it's called a can type. It has ears with holes that I imagine are for mounting to a heat sink. On the top it has two alphanumeric strings. The top string "B-10603" is printed radially around the rim and the bottom string "6812D" is straight. There is s letter "B" in italic in the center. On the underside the pins are identified by a letter stamped into the metal,(C,B,E). With my multimeter in the diode function it measures 0.135v from emitter to base and 0.082v from collector to base with the neg. lead on the base for both, so I guess it's a PNP, right? I tried to do a google search with both strings with no luck. Any info on this or what I might be able to do with it would be greatly appreciated. Thanks.

[petemoore]

  Get a DMM with Hfe feature, start plugging the three legs in the four socket holes provided on the NPN side and the PNP side, determine the pinout this way, when you get some kind of Ge reading [useful at all is above say 30hfe, leaky or gainy ones will reader higher Hfe, when some number looks like gain, your pinout is shown by the Hfe socket markings.
 EBCB is how mine are marked, with this I can try all possible pinout and polarities [npn or pnp] + get some gain reading which hasn't had the leakage subtracted, DMM's generally don't test for leakage but ones with Hfe can be among the least expensive.
 RG has written the Fuzzface article and how to test GE transistors at GEO.
 Kind of interesting though to see what you think first, you may notice the ones with leakage are noisey or don't seem like they have the gain the meter alone suggests.

[head_spaz]

The package you're describing sounds like a T0-3 or T0-66.
These packages typically housed large power transistors, used in powersupplies, output drivers in power amps... etc...

In your searches, try adding the following prefixes, which were quite common way back when...
2SA-6812D
2SB-6812D  or perhaps 2SB-10603
2SC
2SD

For germanium, I think it was 2SA for pnp, 2SB for npn, or vice versa.

[JDoyle]

The package you're describing sounds like a T0-3 or T0-66.
These packages typically housed large power transistors, used in powersupplies, output drivers in power amps... etc...

In your searches, try adding the following prefixes, which were quite common way back when...
2SA-6812D
2SB-6812D  or perhaps 2SB-10603
2SC
2SD

For germanium, I think it was 2SA for pnp, 2SB for npn, or vice versa.

2SA and 2SB are both PNP types with 2SB being specifically for low frequency. 2SC and 2SD are NPN with 2SD being low frequency.

However, the number mentioned is too high to be one of those types. I don't know what it is to be honest but I am guessing the "6812D" is the lot number - made in the fourth week of December, 1968.

The B10603 is probably the part number. RCA and TI both had five character numeric part numbers when they first started making transistors. Back in germanium days they hadn't standardized the numbering system yet - but that doesn't much matter as every germanium transistor from back then was made by hand, and was therefore different from the next one.

Regards,

Jay

[joegagan]

i have found some very early germs in my town at the surplus places. we are a key military/nuclear area. (NM).

RCA transistor with the marking B22. it is one of the best sounding trannies i have ever heard. i use it as a benchmark.

[humptydumpty]

i might sound very stupid, but what are these surplus stores you are all talking about?

[Wild E]

Thanks for the shot of "there's so much more to learn" petemoore! I'm still new at this hobby and wouldn't know what to do with that info if it was handed to me on a silver platter.
Should I find a Ge fuzz circuit to throw it in and see what happens? Anyone have suggestions? Are there some approximate biasing voltages I should be looking for? joegagan's comment has me chomping at the bit to see what this will do, they have quite a few of these left.
The surplus store I go to buys all sorts of stuff from stores that are closing or have items that aren't moving, people's sheds, companies that upgrade equipment and sell off the old stuff, etc. I like to call it "inventor's paradise".The only problem is they don't know anything about the chips and trannys they have.

[Wild E]

OK, I did the tranny test on geofex http://www.geofex.com/Article_Folders/ffselect.htm and got leakage over 5V on one and over 6V on the other so I guess they're going to become clipping diodes in the future unless anyone has any better ideas. Thanks to all who replied!