Motorola supplementary TO3 stamp codes

[N_Cook]

I can't say I'd noticed them before today
Is there a cross-reference anwhere ? not necessary this time but if the
printed marking is faded/damaged/burnt/ground off, another time

A batch of 1988 MJ150024 with stamped code D14 around a mounting hole
batch of 1988 MJ15025 stamp code D13
1979 MJ15003 double stamped 924 CD

I don't know if UK amp maker "Exposure" uses rebadged Motorola but marked
EXP8P (pnp) and stamped C5 in similar position
EXP8N (npn) stamped C4 in an Exposure VIII of 1988

If anyone else cares to add here a few more they have lying around it may be
useful sometime

 

[N_Cook]

I can't say I'd noticed them before today
Is there a cross-reference anwhere ? not necessary this time but if the
printed marking is faded/damaged/burnt/ground off, another time

A batch of 1988 MJ150024 with stamped code D14 around a mounting hole
batch of 1988 MJ15025 stamp code D13
1979 MJ15003 double stamped 924 CD

I don't know if UK amp maker "Exposure" uses rebadged Motorola but marked
EXP8P (pnp) and stamped C5 in similar position
EXP8N (npn) stamped C4 in an Exposure VIII of 1988

If anyone else cares to add here a few more they have lying around it may be
useful sometime

the 924 one may be a supplemental metalwork datecode without the 7,
preceeding the printed datecode of 7927 nand CD is the typecode for that one

 

[N_Cook]

Motorola was always happy to ship parts with a customer's part
number, if you bought enough parts. No need to remark them.

Those numbers he's seeing may indicate the set of tooling used to
seal the TO-3 can for quality control. That way they could track it
back to a particular plant or production line, along with the date
codes.

Would there be a correlation between those stamp codes and the printed type
number and so of some use to repair folk or would there be too much
one-to-many mapping rather than 1 to 1? one stamp code used for dozens of
types so not much use outside Motorola.

 

[N_Cook]

Motorola was always happy to ship parts with a customer's part
number, if you bought enough parts. No need to remark them.

Those numbers he's seeing may indicate the set of tooling used to
seal the TO-3 can for quality control. That way they could track it
back to a particular plant or production line, along with the date
codes.

In the vintage valve/tube world these
http://www.audiotubes.com/mullcode.htm
small etched codes are very useful where the chalky printed type numbers
have diasappeared off the glass envelopes

 

[Phil Allison]

"N_Kook"

I can't say I'd noticed them before today

** Been there since the 1970s.

They stopped doing it in the early 90s.

Is there a cross-reference anwhere ?

** Not one you can easily access.

A batch of 1988 MJ150024 with stamped code D14 around a mounting hole
batch of 1988 MJ15025 stamp code D13

** Identifies the part number of the chip in the pack.

Motorola applied inked numbers at a later date, when orders were being
filled.

1979 MJ15003 double stamped 924 CD

** The "924" indicates it was assembled in the 24th week of 1979.

"CD" indicates an MJ15003.

"BP" indicates a 2N3055.

"DID" indicates an MJ15024

"DIB" indicates an MJ15015

"34P" also indicates an MJ15003

"CFF" and "CFFY" indicate an MJ423

"CAH " indicates an MJ1800


All this was very important to know back in the 1980s when I first came
across a whole variety of FAKED Motorola parts at " Dick Smith Electronics
" - and also at Rod Irving Electronics with Motorola 2N3055s and MJ2955s
that had been scrubbed and relabelled as MJ15003s and MJ15004s.

Nasty business.

Lawyers even got involved.


..... Phil

 

[N_Cook]

"N_Kook"


** Been there since the 1970s.

They stopped doing it in the early 90s.



** Not one you can easily access.



** Identifies the part number of the chip in the pack.

Motorola applied inked numbers at a later date, when orders were being
filled.



** The "924" indicates it was assembled in the 24th week of 1979.

"CD" indicates an MJ15003.

"BP" indicates a 2N3055.

"DID" indicates an MJ15024

"DIB" indicates an MJ15015

"34P" also indicates an MJ15003

"CFF" and "CFFY" indicate an MJ423

"CAH " indicates an MJ1800


All this was very important to know back in the 1980s when I first came
across a whole variety of FAKED Motorola parts at " Dick Smith Electronics
" - and also at Rod Irving Electronics with Motorola 2N3055s and MJ2955s
that had been scrubbed and relabelled as MJ15003s and MJ15004s.

Nasty business.

Lawyers even got involved.

That is the sort of correlation I was after. I take it there was a simple
correlation in the late 70s but by the late 80s it was no longer the case.
I see TO3 , RCA make ones also have such punched numbers, but more complex
spaced characters