Icom IC-M412 Service Manual page 29

SECTION 9 BLOCK DIAGRAM
HM-164B
MIC
PTT
KEYM
FRONT-A UNIT
IC9:LA4425A
SP1 INT SP
AF
AM P
R1
045P0806-7-1
VR-A UNIT
R1
VOL1
VOL2
HV
VCC
SQL-A UNIT
R1
5V
LOGIC-A UNIT
IC2A:
LM2904PWR
LCD
BPFV
BUFF
IC2B:
LM2904PWR
LCD DSCENC
BUFF
Driver
IC8:NJU6535FH 1
LCD-DR KEY
5V CTR BOARD
Q5:KRA304
Q4:DTC144TU
D1:KDS4148U X1:CR-836
9.8304MHz
ICF3 CI-V
I/F IC4:
S-80942CNMC
IC1:UPD78F1153GK
RESET
Q1:KTA1664 CPU
Q2,Q3:KTC4075x2
VCC
DIM
CTRL
EEPROM
DS2-DS7: IC3:
L-C191KYCT HN58X2464TI
DS8-DS13:
RY-SP110UHY24
External GPS I C5:PC357N6J
D2:KDS4148U
NMEAI+
PHOTO
NMEAI- COUPLER
5V
PTT
KEYM
ICF3
MAIN-A UNIT
BPFV
EXT SP
IC4Z:CD4053B I C11:NJM2125F
BEEP SQ L SQL
AMP
RMUT E
IC4Y Q31,32:
BPCON CD4053B KTC4075x2
AF
BPF
MUT E
H/L
IC15:NJM2211M Q65:KTC4075
DSCDEC DSC
LPF
DECODER
RX VCO
VCC
MAIN-RX:134.300–141.725 MHz
IC5: IC8B:
TC7S66FU NJM4558M
MIC AF MICAMP
MUTE +IDC
R309
MICM
HV
REVERSE
CONNECT
PROTECT
D42:DSA3A1
5V
VCC
9 - 1
FI3:LTM450EW
X2:JTB450C24
CERAMIC
BPF
FM 2ND IF 2ND
DET AM P MIX
NOISE
2ND LO
NOISE
AM P DET BUFF
R214
IC2:TA31136FN
IC4X
CD4053B
FI6:LTM450EW
X4:JTB450C24
CERAMIC
R5
BPF
FM 2ND IF 2ND
DET AM P MIX
Q63:KTC3880S
NOISE 2ND LO
NOISE
AM P DET BUFF
I C14:TA31136FN
Q70:KTC404
Q71:KTC4075 D 53:MA2S077
R8 RVCO8 RVCOV SHIFT
CTRL
5V
LOOP VCO
FIL
X1:CR-804
21.25MHz Q85 Q 72:PMBFJ310
KTC4080 D51,D52:HVC358Cx2
Q 75:2SC4215
LPF
3.6V
I C1:MB15F72ULPFT
PLL
LPF
Q4,Q5:2SC4226x2
D3:HVC350B
LOOP
VCO
FIL
IC8A:
NJM4558M
R5
LPF
MOD SHIFT VCO5
R327
Q 2:KTC404
D 1,D2:MA2S077x2
TXCH70 VCO
TX:156.000−161.450 MHz
CH70-RX:125.650 MHz
MAIN-RX
FI1:FL-368
FI2:FL-412 Q21:3SK131
Q22:3SK293
IF XTAL RF
BPF
AM P BPF AMP
Q23:KTC3880S 21.7MHz D26,D27,D28:
1SV214x3
R5
CH70-RX
FI4,5:FL-413x2 Q61:3SK131
Q62:3SK293
IF XTAL RF
BPF
AMP BPF AMP
30.875M
X5:CR-845
30.425MHz
RVSIF
Q76:SC4215
BUFF BUFF
Q74:2SC4215
BUFF
D7,D8: Q10:
Q3:2SC4215 Q7:2SC4215 M A2S077x2 2SC4226
TX/RX YG R
BUFF BUFF
SW AM P
Q6:2SC4215
BUFF
Q1:KTC4075
VCO5 5V
CTRL
SEND
Q57:KTA2015
Q58:KRC404
VCC +5 5V T5
REG CTRL
IC10:KIA7805API
IC16: Q53:KTA2015
S-812C36 Q54,Q59:KRC404x2
3.6V 3.6V 5V R5 R5
REG CTRL
RCV
R8
REG
Q55:KTA1664
Q56:KTC4075
Frequency range
TX :156.000-161.450MHz
MAIN-RX:156.000-163.425MHz
CH70-RX:156.525MHz
L35:C2520C
TRAP
LPF
ANT
D 14,D21:
XB15A308x2
ANT
LPF
SW
IC3:
S-AV35A
PWR
LPF
AMP
HV D 12,D13:
HSM88ASRx2
RF OUT TXDE T
DET
R112
Q14:KTA2015
Q15:XP1501 Q16:KRC402
APC PWR H/L
T5 CTRL CTRL
R106
TX MUT E TMUTE
CTRL
Q17,18 :
KRC404x2
R8