Need help identifying pinout old some old Germanium PNP

dano · Post by **dano** » 10 Apr 2009, 19:11

I've just got my hands on an box of old Germanium PNPs which are NKT ACY21 with date code 7424, thinking about building a fuzz with these.

I'm having trouble determining the pinout of them though, the metal cap isn't connected to any of the pins for start.

I've got this table of values using the diode test, but I''m not reaslly understanding which is base, collector and emittter

test pin1 pin2 pin3 Voltage (diode test)
1 n/c blk red 0.17V
2 blk n/c red 1.24V
3 blk red n/c -
4 n/c red blk -
5 red n/c blk -
6 red blk n/c 0.102V

I'm thinking pin2 is the base (using test 1 and 6) but I don't understand the reading I get for test 2 (1.24V).

P1NkY · Post by **P1NkY** » 10 Apr 2009, 19:47

The datasheet is here: http://www.datasheetarchive.com/pdf-dat ... nt6288.pdf
Pinout for the ACY21 germanium PNP transistor (in a TO-5 case) is illustrated here: http://english.electronica-pt.com/db/cr ... ?ref=ACY21
Hope it's what you're looking for.

dano · Post by **dano** » 11 Apr 2009, 18:04

Thanks for the link, it's confirmed what I was thinking regarding pinout. Just measured a few now and have hfe's of 160-220 so looks like I've got a good batch to experiment with.