Icom IC-F21 Service Manual page 32

SECTION 11 BLOCK DIAGRAM
S5V
Q13
2SK880
BUFF
LVIN
X1
CR-671A
IC1
MB15A02PFV1
REF
15.3MHz
PLL LOOP
BAL REF
IC FIL
Q31
2SC4215
PLST
D19
SO
HVC362
x 3 SCK
UNLK
Q18
393.65–470MHz
2SC4116
DEV
2ndLO
45.9 MHz
BPF
NOIS
DET
DET
IC9
M62363FP
T1
T2
T3
DET T4
DEV D/A
BAL
REF
DAST
SCK
SO
IC13
TC7S66FU
ANALOG
SW
DET RESTO-
LPF
RATION
IC12A IC12B
NJM12904V NJM12904V
DET
LPF
IC5A
NJM13403V
Q12 Q8 DTC144EU
XP6501
Q9 XP1214
R5V
VCO
RIPPLE
FIL SW
Q10 2SC5085
D5 HVU350
Q7 Q5
RX VCO 2SC5107 2SC5107
BUFF BUFF
Q11 2SC5085
D6
D7 HVU350
MA368
TX VCO
MOD
LPF
BUFF
Q6
2SC5107
IC3
TA31136FN Q17 FI1
2SC4215 FL-313
IF IC
2nd MIXER
XTRL
IF AMP AMP
BPF
SQL AMP
DETECTOR
RSSI
X2
CDBCA450CX24
FI2
450kHz
CERAMIC
BPF
ALFYM450F=K
MIC
IC5C IC6
NJM13403V BU4066BCFV
HPF
AMP
IC5D
NJM13403V
ANALOG
IC5B SW
NJM13403V
HPF
Q21
DTC144EU
NWC W/N
SW
CTCSS/DTCS
Q29 IC16
2SC4116 NJM12904V
CENC0
CENC1
CENC2
LPF LPF
Q30
Q28
XP1213
DTC144EU
DUSE
FIL FIL
SW SW
CDEC
SDEC
11 - 1
MAIN UNIT
D3,D4
Q4 Q3
MA77
2SC5107 2SC3585
YGR
TX / RX YGR
SW AMP
AMP
1stLO
ATT
393.65–423.65 MHz
D15 D14
Q19
HVU350 HVU350
3SK272
46.35MHz
BPF BPF
1st MIXER
2ch VERSION
S1 AS-244-A13
IC6
BU4066BCFV
SW-A/SW-B UNIT
R1
ANALOG
LPF
AF VR
SW
VOLIN
DS1
LNJ107W5PRW Q1 XP4216
BUSY LED
TX LED
SENC0
SENC1
SENC2
SENC3
VCC
IC10
NJM2870
+5
+5V
REG
Q23
DTA144EU
Q24
Q25
2SB1132
XP6501
S5 S5
S5V
CONT
REG
Q26
2SA1577
R5
R5V
REG
Q27
2SA1577
T5
T5V
REG
Q1 D2 D1 1SV307
Q2
RB706F-40 D9,D10 MA77
2SK2974
2SK2973
ANT
PRE PWR PWR
SW
DRIVE AMP DET
IC2
TA75S01F
Q33
3SK1829 APC
AMP
RSSI
AGC
CONT
D12
D13
HVU350
HVU350
RF
BPF BPF
AMP
Q15
3SK293
+5V
Q22
UN911H
PTT
PTT
SW
CBI0
Q19 2SB1132
Q20 XP6501
S1 VCC AFON
AF AMP
SW-A TP70QF4161
REG
SW-B (EMER) SKHHLP014A
CH SELECT
/EMERGENCY
VOLOUT AF AFOUT
AMP
IC4 CLONE
F1 TA7368F
HV BATT
FUSE CBI0
CBI1
CBI2
CBI3
RLED
CLONE
LED SW
TLED BUFF
CLI,CLO
F1
F2
PTT
TXC
IC8
S-8094ANMP BEEP
CPU
RES IC7 NOIS
RESET
HD6433664
RSSI
LVIN
CPU5V
BDET
IC11
HN58X2416TI TEMP
SCK
ESDA BATV
EEPROM
SO
IC15
SCK
RMUT
EXST
MMUT
Explanatory notes
DUSE
X3
CR-702
NWC
EXP-
S5C ANDER
CSFT D16
R5C
SHIFT
MA77
SW
T5C
BU4094BCFV
ANT
440–470MHz
LPF
Q14
DTA144EU
TXC
MUTE
SW
J4
EXT.MIC
HSJ1122 010010
MC1
KUC3523
MIC
INT.MIC
S3
PTT
SP+
SP–
INT.SP
J5
EXT.SP
HSJ1456-01-220A
D17 RB706F-40
Q32 DTC144TU
F1
F2
CONTROL LINE
COMMON LINE
TX LINE
RX LINE