Icom IC-F4021T Service Manual page 37

CONNECT UNIT
J901
L901 L902
VCC
2 BLM21P300S BLM21P300S
BATT
VCC
1
GND
L903
BLM21P300S
TX: 7.0V
TX: 7.1V
F701 RX: 7.2V RX: 7.2V
0467003.NR R729
VCC 2 1 HV 0.15
VCC R730 1k
TO CONNECT
UNIT J901
Q705
XP6401
T5V
EP701
ACZ1005Y
[L]
C762
0.5p
[L]
C761 C731
0.5p 3p
Q703
TX: 6.5V
2SC3356
RX: 6.8V
J701 C733
TX: 0.85V[H]
3p
0.68V[L]
TX
RX: 0V
4
GND
Q706
TO MAIN 3
Q704
T5V
UNIT 2SC4081
2 TX: 0.72V
VCC 2SC5006
RX: 0V
1
Q701
RD07MVS1
Q702
C720
C729 RD01MUS1 33p[H]
6p
39p[L]
MP701
PA heat sink
APC L704
0.4-0.9-2TL
C784
0.001
T5V
R745
47
TX Hi: 2.33V[H] R744
1.38V[L] 330k
5 3
TX Lo: 1.90V[H] APC
APC 4
1.07V[L]
1
RX: 0V
R746
2
1k
IC701
TA75S01F
D701
C708 L703 C701
1SV307
0.001 0.4-0.9-2TL
0.001
TX: 1.42V[H]
1.60V[L]
RX: 0V
L709
[H]
14nH
R727 C742
D703 D702 0.001
2.7k
RB706F-40 RB706F-40
C745
1.5p[H]
2.5p[L]
LPF
TX: 0.57V
RX: 0V R742
27k
P_DET
T5V
C752
L712
J702 0.001[H]
22nH
12p[L]
RX
1
GND
TO
2
TI
MAIN UNIT
3
ISENS
4
TX
GND TX: 0.71V[H]
TX: 0.86V
PA UNIT
0.65V[L] RX: 0V[H]
RX: 0V 0.2V[L]
L802 L801
21nH 15nH
TX
GND
C802
[L]
1p[H]
0.5p[L]
ANT UNIT
BATTERY
CONNECTOR
J2
MEASUREMENT CONDITIONS
DIGITAL VOLTMETER
FREQUENCY: 485.1MHz[High band]
435.15MHz[Low band]
[L] = Low band
[H] = High band
Explanatory notes
J1
(CHASSIS)
TX LINE
RX LINE
COMMON LINE
VOLTAGE LINE
12 - 2