Vectronics VEC-422K User Manual
Page 15

VEC-422K Owner's Manual
SCA Decoder Kit
13
Semiconductors:
2N3904
Note: The 2N3904 transistor body has a flat and rounded side. The device body
outline must correspond to the silk-screened component outline on the PC
board.
Locate the four 2N3904 plastic transistors. Install and solder at the following
locations:
! ! 1."Q1
2N3904 transistor, observe alignment!
! ! 2."Q2
2N3904 transistor, observe alignment!
! ! 3."Q3
2N3904 transistor, observe alignment!
! ! 4."Q4
2N3904 transistor, observe alignment!
Locate the 14-pin IC socket. Note that the socket is keyed—a small notch shows
pin 1 alignment.
1 2 3 4 5 6 7
14 13 12 11 10 9 8
Installation
Key
Pin Numbers
Top view of socket
! ! 5. Install and solder the 14-pin IC socket at location U1. Observe that
the key aligns with the legend outline on the PC board.