+5V
+5V
D4
1N457
C11
.22uF
C15
.022uF
White
4
+5V
Receive
Coil
C8
4700pF
C9
.1uF
R8
1K
R13
49.9K
1
7
R4
49.9 ohm
Q2
2N4403
12
C14
.47uF
6
16
13
R16
560
8
U3
12
C22
22pF
6
+2.5V
C20
22pF
Discrimination
R20
49.9k
C18
.47uF
R32
100K
+2.5V
7
+2.5V
R10
20K
Shield
D8
1N4148
8
+5V
10
R26
270K
4 7
R31
1K
Q3
MPS A13
C23
.01uF
R35
100 ohm
R30
6.8K
SP1
16 ohm
+2.5V
R23
20K
R27
270K
5
+2.5V
D5
D6
1N457 1N457
9
U2
R18
1M
U2
D2
1N4148
C10
2200pF
+5V
5
R17
10K
R14
49.9K
Red
C5
.22uF
R22
20K
4
11 14
C16
.022uF
U1
R5
3.92K
R28
75K
D7
1N457
R12
20K
14
+5V
U2
+2.5V
C12
.22uF
1M
Transmit
Coil
13
R21
2.7M
1
8
R7
2.7K
C2
100uF
10V
9
3
Part of
U1
Q1
2N4403
Part of
U1
R15
1M
U2
D1
1N4148
R9
10K
+5V
R3
1K
2
6
3
R6
10K
Ground
Compensation
C13
.47uF
5
U1
11
Green
10
C19
22pF
R11
20K
R1
1K
D3
1N457
+2.5V
C7
.22uF
11
+8V
+2.5V
3
D9
1N4148
U3
1
R24
1M
2
R25
75K
Black
C21
1800pF
+8V
D10
1N4004
+5V
R2
2.7K
VR1
+2.5V
LM2931
9V
D11
1N4148
C1
1000uF
16V
C3
33uF
10V
VR2
TI105BX
C4
33uF
10V
U1 LM13700N
U2 TLC27M4CN
U3 LM392N
Fisher 1212X
Traced from PCB
by Rodney Gray
Orig. 1992
Revd. 10/31/06