Old Transistor ID, please!!

[Joe Hart]

I am always scavenging parts and would like to know if there is a chart for transistors numbers? I have an old 1970’s stereo that has some interesting looking transistors in them and I have no idea if they are good for anything or even what they are! Any help would be appreciated! Thanks.
-Joe Hart

The numbers on them are:

Little black ball shape with 844 printed on it.
Same with 846 on it.
Same with 838 on it.

Metal can with a heat sink collar on it with 852 99P2AA on the side.

Regular black half-moon shape with 83P2 8912 on the flat side.
Same with 84N1 B352 on the flat side.
One with 94N1 843 around the edge.

[Joe Hart]

Anyone? Even just a site that I could look stuff up on? I tried Google, but I couldn't find the info. Maybe I wasn't using the right keywords. Thanks.
-Joe Hart

[Rob Strand]

I tried to find something out the other day when you started the thread.  I plugged pieces of those number into search engines and looked through the stuff I have and I couldn't find anything.  Some parts of the number could be date codes but after looking at each number I couldn't discern a pattern which would let me work that out.

HiFi amps are often filled with standard parts which have been custom stamped.  Perhaps if you could post the brand and/or model of the unit someone might be able to hone in on a list or something.

It's not that I didn't try, it's just I couldn't find *anything* useful to report.

[Nasse]

What kind of stereo equipment is it? If it is some big name and the country where it is manufactured is known you may find where to start diggin.

If they can measured somehow or just plug in a breadboard you dont need to know exact type. You could guess some of your trannies might be silicon trannies, and measuring hfe and pin identification is not impossible. Transistors dont take much room in a junk box, maybe you can store them till you find some info.

I bought few pnp silicon trannies 20 years ago for a mic preamp job, the man in the component shop told they are "low noise" ones. Project never get ready, but last winter found those trannies in my junk box and they found a home in a nice sounding Fuzz Face.

[Paul Perry (Frostwave)]

All the 'black half moon' stuff from this era is silicon, in my experience. There isn't 'enough number' to get any hits in any of my references from then. Might be 2SBxxx or 2SCxxx, but my advice is just plug them into a RS meter with the transistor lead indicator.

[Johan]

this is copied from http://www.elfa.se/en/fakta.pdf go down to transistors/thyristors.....these factpages are a great resorce for whatever you might want to look into...

The European Pro Electron System
Two or three letters followed by a 3- or 4-digit group of numbers
provide a rough understanding of the component type as well as
the power class.
The first letter indicates the material:
A Ge, Germanium or a material with a band gap of 0.6-1 eV
B Si, Silicon or another material with a band gap of 1-1.3 eV
C GaAs, Gallium arsenide or another material with a band
gap greater than 1.3 eV
The second letter indicates component type:
A Diodes, signal, low-level
B Capacitance diodes
C Transistors, low frequency, low level
D Transistors, low frequency, power
E Tunnel diodes
F Transistors, HF, low level
H Diodes, Hall effect components
L Transistors, HF, power
N Opto switches
P e.g. Photo-transistors
Q e.g. LEDs, laser diodes
R Thyristors, low level
STransistors, switch, low power
T Thyristors, power
U Transistors, power, switch
W Surface wave components
X Diodes, HF multiplicator
Y Rectifiers, booster
Z Zener diodes, voltage reference
A third letter indicates that the component is designed for industrial
or professional applications. This letter is usually W, X, Y or Z. After
these letters comes a serial number with 3 to 4 digits and, in some
cases, an additional letter that can indicate the amplification factor
for example.

The American system is not entirely without its ambiguities. Roughly
speaking, a transistor that begins with 2N, like e.g. 2N2222, can
be a bipolar transistor, while 2N3819 is a JFET. A designation that
begins with 3N, like e.g. 3N128, indicates that it is a MOSFET.
Some manufacturers also use letter designations like TIP34,
MJE3055, etc.

The Japanese JIS System (Japanese Industrial Standard)
First digit (one less than the
no. of connections):
1 Two connections
2 Three connections
3 Four connections
The two following letters:
SA PNP transistors and Darlington (HF)
SB PNP transistors and Darlington (LF)
SC NPN transistors and Darlington (HF)
SD NPN transistors and Darlington (LF)
SE Diodes
SF Thyristors
SG Gunn diodes
SH Unijunction transistors
SJ P-channel FET
SK N-channel FET
SM Triacs, bidirectional thyristors
SQ LEDs
SR Rectifier diodes
SS Signal diodes
ST Avalanche diodes
SV Capacitance diodes, PIN diodes
SZ Zener diodes

The serial number consists of two to four digits within a number
range between 10 - 9999. This is followed by a suffix that consists of
one or several letters. The last letter indicates the area in which the
semiconductor is used.
D Approved by the Japanese telecom authorities (NTT)
G The component is used for communication
M Approved by the Japanese Navy (DAMGS)
N Approved by the Japanese Broadcasting Corporation
(NHK)
SDesigned for industrial applications
The Japanese Industrial Standard (JIS) designation does not
indicate whether a semiconductor is manufactured from silicon or
germanium. The first two characters are frequently omitted on
drawings as well as on the printed serial number on the components
themselves. This means that a 2SC940 type transistor may
very well be marked C940.

It got a little long, but I think it is usefull for anyone pulling parts from old boards...

Johan