Tach question

[SSDD]

Hi all, i have downloaded the:

Simplified tach driver for older tachs

on the Diagram the 12v is going in through the R1 680 ohm res then conecting to Q1 the BC 109 trans, the second pin is of the Q1 is for the MJLJ output and the 3rd is earth, from this:

http://www.a-car.com/john/info/tup_tun_specifics.htm

can someone tell me what B,C,& E are on the BC109?

Thanks Steve

[MartinM]

B = Base = connected to the MJLJ
C = Collector = connected to R1/Tacho
E = Emitter - connected to ground

Just make sure, as stated in the pinout diagram, that you are looking at the bottom of the transistor