Service manual
2-33
March 2000
Part No. 001-3139-502
800 MHz RECEIVER SCHEMATIC
FIGURE 2-13
FOLDOUT
C57
.01
R29
100k
C58
.001
L19
CR3
C59
1.9-15.7pF
C60
33pF
Y1
R30
47k
R31
27k
C61
100pF
C62
300pF
Q4
3002
R32
470
L20
C63
39pF
C65
.75pF
L21
C67
68pF
C64
.01
R33
47
C68
68pF
C69
4.7pF
CR4
R37
10k
C74
.01
TP4
R34
47k
R35
10k
Q5
3002
L22
R36
470
C73
.001
C71
22pF
C72
22pF
C70
.01
R38
47
R39
47k
R40
10k
Q6
3002
L23
R41
220
C77
11pF
C79
12pF
C81
12pF
R43
47
C80
470pF
+
C154
100
C78
.01
C82
470pF
C83
39pF
C84
62pF
C149
.01
C150
470pF
R42
10
C76
.01
C75
100pF
+9V
R44
10k
R45
47k
C85
2pF
CR5
R46
10k
C87
.001
TP5
L24
L25
R47
220
C86
11pF
R48
270
C91
3pF
C90
10pF
C88
.01
C89
100pF
R49
47
Q7
3037
R50
10k
R51
47k
C93
10pF
C94
.001
R52
220
C92
39pF
Q8
3066
C95
.68pF
CR6
R53
10k
C97
100pF
TP6
L26
L27
L28
C96
2pF
FIRST OSCILLATOR/TRIPLER
FIRST
DOUBLER
SECOND
DOUBLER
THIRD
DOUBLER
FOURTH
DOUBLER
Q9
3053
C66
.001
R58
100k
R59
1k
C102
.01
1
8
6
12
13
2
R60
4.7k
CLK
MR
C103
.01
W103
R61
4.7k
CLK
MR
U3
54LS393
QD
QD
C106
.1
C156
.01
+5V
9
Q1/C2
C1
2
15
10
C104
.1
4
5
6
7
11
14
3
+5V
U4
4568
DUAL BINARY COUNTER
OSCILLATOR PHASE-LOCK
PE
0
PC
IN
CTL
F
DP4
DP3
DP2
DP1
G
13
PC
OUT
R63
100k
R64
10k
R65
100k
CR9
CR10
+
C107
1
R66
10k
+
C108
100
C105
.001
1
2
1
3
4
5
A
D
B
C
12
9
Q
11
13
14
15
+5V
B
CD
T2
T1
U5
4528
R62
10k
C105
.001
CR11
R67
10k
RETRIGGERABLE
MONOSTABLE MULTIVIBRATOR
C10
11pF
L6
L7 L8
L9 L10
L11
C11
2pF
C12
11pF
C14
.0022
R4
1.8k
R5
3.3k
Q1
3052
R6
470
C19
.0022
C21
56pF
C24
56pF
C15
11pF
C27
.01
R8
10
C16
.0022
R7
10k
L12
C17
11pF
C18
2.2pF
C25
10pF
L13
C26
12pF
Z1
C28
8.2pF
L14
R9
100k
R12
2.7k
C29
.01
R11
10k
Q3
6009
T1
C30
20pF
R13
10k
C37
.01
C36
47pF
T2
3
2
4
1
1
2
4
3
5
10
8
U1
2203
C38
.01
C35
.0022
R14
10
C34
.01
C39
82pF
+9V
C32
.33pF
C33
1.8pF
C152
.33pF
Z2 Z3
C153
.33pF
C160
1.8pF
C155
.33pF
Z6
R17
3.9k
C44
.01
T4
2
3
4
1
U2
CA3089E
C45
12pF
C49
.01
R19
2.2k
C48
2.7pF
T5
2
5
9
4
7
8
1
3
C43
.01
14
10
R20
4.7k
Z4
Z5
L15
R22
3.3k
R23
330
R24
2.2k
C46
.1
R21
33
C47
.01
11 12
15
16
+13.8V
6
T3
1
43
2
R16
6.8k
TP2
TP3
13
C42
.01
R18
33k
TP1
C55
.01
+
C56
1
R27
10k
R10
100
Q2
6014
Y2
55.7MHz
R28
390
C51
100pF
L16
C50
33pF
C53
1pF
SECOND OSCILLATOR
HELICAL BANDPASS FILTER
FIRST MIXER
45 MHz CRYSTAL FILTER
SECOND MIXER
10.7 MHz CRYSTAL FILTER
IF AMPLIFIER
10.7 MHz CRYSTAL FILTER
DISCRIMINATOR
TCXO REF
FROM
EXCITER
J4
RX DATA/AUDIO
C109
.1
R68
47k
C110
.0033
R70
22k
R69
47k
C111
820pF
U6B
3303
+
+4.5V
6
5
7
R71
10k
C112
.047
C159
.33
C113
.22
R72
100
U6C
3303
+
C115
.033
9
10
8
C114
.047
R73
1M
+4.5V
C116
.15
R74
100
U6D
3303
+
13
12
14
C117
.047
R75
1M
+4.5V
C119
.1
+9V
C118
.047
R76
10k
U6A
3303
+
2
3
1
+4.5V
R77
120k
C120
.01
J5
AUDIO
TEST
JACK
43
5
21
13
98
6
R79
10k
R80
10k
+9V
U7B
4066
U7A
4066
U7C
4066
LOW-PASS FITLER <3 kHz
HIGH-PASS FITLER >300 Hz DE-EMPHASIS
AUDIO GATING
RX AUDIO
SQUELCH ENABLE
(FROM LOGIC J701-14)
(TO EXCITER J401-1)
(TO LOGIC J701-1)
C141
.1
C138
.1
C134
.1
C137
11pF
Q
Q
13
12
U10B
4013
C
D
9
11
R
10
S
8
C139
11pF
R95
10k
R96
10k
+9V
ANT 1 ANT 2
S1
ANTENNA SWITCH
TOGGLE FLIP-FLOP
C
3
5
D
S
6
R
4
CR16
R94
68k
C136
.01
U10A
4013
Q
Q
2
1
+9V
C135
11pF
U9C
3303
+
10
8
14
R93
100k
R92
100k
9
U9D
3303
+
R89
10k
CR12
CR14
CR13
CR15
C133
.01
U8A
3303
+
2
1
C140
11pF
R87
200k
R86
5.1k
C132
1000pF
U8B
3303
+
6
7
R84
150k
C130
100pF
C131
100pF
C129
100pF
R85
18k
J2
ANTENNA 1
C1
11pF
J3
ANTENNA 2
C3
11pF
R1
2.2k
C9
11pF
L2
L4
L5
C4
3.6pF
C2
3.6pF
C157
100pF
C5
11pF
R2
2.2k
L1
CR1
CR2
C7
1pF
C158
100pF
C6
11pF
R3
2.2k
L3
C8
1pF
13
123
5
DIVIRSITY SWITCH
1
10
14
R78
100k
+4.5V
+
C121
10
R81
10k
ON/OFF/VOL
3
R82
18
+
C123
10
4
2
1
C127
.047
5
C192
.1
C126
3300pF
+
C125
10
R83
39
7
C151
.01
+13.8V
+
C128
220
LS1
LOCAL SPEAKER
8 OHM
U9B
3303
+
6
7
5
C142
.01
R97
4.7k
R110
6.8k
RT100
8k
R98
12k
C136
.01
C143
.01
CR17
CR19
CR18
CR20
R99
10k
R100
10k
R101
47k
C145
.1
U9A
3303
+
R104
1M
R102
47k
C144
.1
2
1
3
U8D
3303
+
13
14
12
R103
330k
R105
100k
R106
100k
+
C146
1
U8C
3303
+
10
8
9
R108
470k
R107
2.2k
+
C147
1
R109
2.2k
+9V
5 (TO LOGIC J701-5)
PART OF J101 ASSEMBLY
U11
TBA820
12
2
+13.8V DC
AUDIO AMPLIFIER
TIMING BUFFER
SCHMITT TRIGGER
NOISE RECTIFIER
NOISE AMPLIFIER
NOISE SQUELCH CONTROL
NOISE AMPLIFIER
OUTPUT
HIGH-PASS FITLER >30 kHz
NOISE AMPLIFIER
NOISE RECTIFIER
COMPARATOR
ONE-SHOT
DIVERSITY ANTENNA CONTROL
RECEIVE AUDIO PROCESSING
NOTES:
1. ALL CAPACITORS ARE IN MICROFARADS AND ALL RESISTORS ARE IN OHMS
UNLESS OTHERWISE SPECIFIED.
2. IC CONNECTIONS NOT SHOWN:
U3
IC
PIN NUMBER
+9V +5V GND
14 7
U4, U5 16 8
U6, U8, U9 4 11
U7, U10 14 7
16
16
LOGIC NOISE SQUELCH
R88
10k
R91
47k
R90
47k
SQUELCH
ADJUST
IF IN
DC BIAS
AC RET
DC REF
BIAS
QUAD IN GND MUTE IN
GND
QUAD
OUT
AFC OUT
AUDIO OUT
V+
MUTE
OUT
AGC
OUT
NC
TUNE OUT
IN
GND
GAIN
R116
390
R115
1k
R117
51
C170
.1
LOCAL AUDIO
R190
2.7
C190
33
R192
10
6
FREQ
COMP
OUT
Vcc
BOOT
STRAP
+9V
+4.5V
+13.8V
SOURCE
SOURCE
SOURCE
1
3
2
U3
78L09
+
C101
47
+
C99
100
R55
10k
R54
12k
+
C98
6.8uF
R57
180
CR8
5.1V
+
C100
6.8
+5V
SOURCE
-
-
-
R111
22k
CR21