Elenco Electronics ST-751 Assembly Instructions Manual page 5

Refer to Figure 1 or the top legend on the PC board. Install and solder
the following capacitors.
C1 .001mF (102) Discap
C2 .1mF (104) Discap
C3 .1mF (104) Discap
C4 10mF Lytic (see Figure 4)
C5 10mF Lytic (see Figure 4)
C6 10mF Lytic (see Figure 4)
C7 .1mF (104) Discap
C9 10mF Lytic (see Figure 4)
Install and solder the transistors with the flat side in the direction shown
in Figure 1.
Q1 - MPS5172
Q2 - 2N3904
Install D2, the red LED. Cut two 7/16" plastic tubes
to be used as standoffs. Place each LED lead into
the tubing so that the LED stands 7/16" off of the PC
board. Look for the flat side at the base of the LED.
Mount it with the flat side as shown in Figure 1.
Solder into place.
Mount the switch 1/8" off of the PC board, as shown in Figure 5. Install
and solder the switch (S1) in the place shown in Figure 1.
Install the probe tip. Cut a wire to 4 3/4",
strip 1/4" of insulation off of both ends.
Solder one end to point P on the PC
board. Solder the other end of the wire
to the probe tip groove.
One of two types of jacks is supplied
in your kit. Look at the clip on the
jack for identification and wire
accordingly, as shown in Figure 5.
Cut two wires to 1 3/4" and strip 1/4"
of insulation off of both ends. Solder
the wires to the lugs of the jack
supplied as shown in Figure 5.
Solder the other ends of the wires to
the holes in the PC board marked
"EAR" as shown in Figure 5.
Flat
Mount switch 1/8" off
of the PC board.
1/8"
Figure 5
-4-
Electrolytics have polarity.
Place the negative (–) lead in
the correct hole, as marked
on the PC board and part.
Mount the electrolytics so that
they lay on their side.
Figure 4
Flat
Tubes
Clip
Clip