Panasonic SC-AK48, Service Manual

Page: 46 / 104

E
A
Ca
A
AM ANT AM OSC
Z101
1 2 3 4 5 6 7 8 9 10
20 19 18 17 16 15 14 13 12 11
XI
N
CE
DI CL
DO AM LW
SDC
STRQ
FM
IF
IN
MONO
AM
IN
FM
IN
V
DD
PD
AI
N
A
OUT
Vss
X
OUT
L102
0.39 H
R110
1K
C107 0.047
R1
12
100K
C108
8P
C136
1000P
A
B
C
D
R111
390
R128
82
R129
27K
C124
100P C112
0.01
R1
15
560
R116
1K
C
111
25V4.7
D101
UDZSTE175R1B
R1
13
10K
C133
27P C134
27P
X103
(7.2MHz)
R1
17
47K
C130
6.3V100
C132
1000P
C1
13
1000P
R132
10K
R133
1K
R138
3.3K
R130
10K
R137
1K
R136
1K
R135
1K
R134
470
A B C D
C125
16V22
R114
5.6K
C1
10
0.01
A
B
C
D
E
F
IC102
LC72131MDTRM
PLL FREQUENCY
SYNTHESIZER
SCHEMATIC DIAGRAM-7
MAIN(TUNER) CIRCUIT
R103
270
C101
0.01
C102
16V100
R151
82
R152
0
2
3
4
5
1
7
8
6
R1A
100K
R7
2.7K
C9
2.2P
C7
4.7P
C8
3.3P
R8
680K
R9
390
R11
680K
R10
390
R6
390
C10
18P
C6
3.3P
C5
5.6P
R5
560K
C4
180P
C3
2.2P
R3
220
C2A
1000P
R2
100K
C1A
5.6P
FM FRONT END CIRCUIT
L2
0.47 H
L1
1.2
H
D3
SVC21
1SP
A-AL
Q3
2SC2787FL1TA
LOCAL OSC
Q4
2SC2787FL1TA
BUFFER AMP
R4
100K
D1A
SVC21
1SP
A-AL
G
S
D
Q1A
2SK544F-AC
RF AMP
D2A
SVC21
1SP
A-AL
C1
1
1000P
Q2
2SC2786MTA
FM MIXER
O
L11
L10
L12
AM ANT
EXT
LOOP
FM ANT
GND
75
JK101
FM/AM
F=7.2MHz
1.3V
P- P
FM/AM
F=7.2MHz
1.4V
P- P
2.6V
(2.8V)
6.5V 0.8V 0.8V 5.2V 2.5V 0V 4.7V 0V
(0V) (2.4V) (0V)
2.5V 0.6V 0V 0V 5.2V 4.7V 4.3V 0V 0V
(14.6V)
(4.6V) (0.2V)
:POSITIVE VOLTAGE LINE
:FM SIGNAL LINE
:FM OSC SIGNAL LINE
:AM SIGNAL LINE
:AM OSC SIGNAL LINE
F
87.5MHz 108MHz
9.3V
FM
V
2.6V
F
522kHz 1629kHz
1.4V
6.8V
V
AM
SA-AK48
46