![background image](http://html.mh-extra.com/html/icom/ic-91a/ic-91a_service-manual_612375041.webp)
H5
H10
H15
H20
H25
H30
H35
H40
H45
H50
H0
V5
V10
V15
V0
V25
V30
V35
V20
V45
V50
V40
39
40
1
2
to LOGIC unit J401
J702
EXTMIC
INTSP
CLONE
DIUD
DICK
VOL
S-LV
INTPTT
DAFOUT
CHG
TTEMP
UNLK
DASTB1
IOSTB1
TXC
HV
SQL
GND
DATA
CK
GND
AFO
AAF
ANOIS
BNOIS
BRSSI
BAF
+3V
ATONE
BTONE
IOSTB3
IOSTB2
BPS
BPLSTB
REFMOD
APLLSTB
PLLDATA
+5.5V
MOD
VCC
EXT MIC
PTT
SQL
EXT SP
SECTION 10
BOARD LAYOUTS
10 - 1
10-1 LOGIC UNIT
• TOP VIEW
H5
H10
H15
H20
H25
H30
H35
H40
H45
H50
H0
V5
V10
V15
V0
V25
V30
V35
V20
V45
V50
V55
V40
V65
V70
V75
V60
V80
V90
V85
H5
H10
H15
H20
H25
H30
H35
H0
V5
V10
V15
V0
V20
H5
H10
H15
H20
H0
V5
V10
V15
V0
V20
H5
H10
H15
H20
H25
H30
H35
H40
H45
H50
H0
V5
V10
V15
V0
V25
V30
V35
V20
V45
V50
V40
30
to MAIN unit J703
1
16
15
J1001
IFA
GND
BAGC
VBUAC
AR3C
300M800MC
APLLSTB
PLLDATA
DATA
CK
RFR3
+3V
AAGC
GND
RFB
LV
DASTB1
IOSTB1
UNLK
TTEMP
REFC
CHG
T6
MOD
HV
VCC
+5.5V
VCO3V
GND
REF
1
to VCO unit J1
2
15
16
J800
GND
VVCO3
VL
V
GND
MOD
GND
UVCO3
UL
V
BCL
V
GND
VSHIFT
BCVCO3
GND
PLLOUT
GND
LOOUT
BATT-
BATT+
from battery
CHASSIS
J1
CHASSIS
MP28
CHASSIS
W1
DC IN
10-2 MAIN UNIT
• TOP VIEW
10-3 RF UNIT
• TOP VIEW
10-4 UT-121 ( Optional Product ;
CODEC UNIT for IC-91AD)
• TOP VIEW
10-5 VCO UNIT
• TOP VIEW