Icom IC-M803 Service Manual page 72

• MAIN UNIT (4/9)
J4701
C4703
[DSC ANT]
0.1
R4705
100
Q4701
LDTC143ZE
Q4702
22K
L2SC4081
R4703
C4701
10P
R4721
DSCT
560K
MAIN UNIT(3/9)
T8V
Operating band
DSX-RX 2 MHz band
DSX-RX 4 MHz band
DSX-RX 6 MHz band
DSX-RX 8 MHz band
DSX-RX 12 MHz band
DSX-RX 16 MHz band
Any band is not selected.
DB1S
DB1S
DB2S
DB2S
DB3S
DB3S
MAIN UNIT(5/9) DB4S
DB4S
DB5S
DB5S
DB6S
DB6S
14V
D4731 C4731
0.18U 0.27U
L4701 L4702
1SV308 0.1
0.47U 0.47U
0.47U
C4709 C4711 L4704 L4705 L4707 C4719
R4731
82P 18P 0.1
C4722
C4717
3.3K
56P
C4715 68P
33P
DB1S
D4751 C4751
1SV308 0.1
R4751
3.3K
DB2S
D4771 C4771
1SV308 0.1
R4771
3.3K
DB3S
D4791 C4791
1SV308 0.1
R4791
3.3K
DB4S
D4811
1SV308
R4811
3.3K
Control voltage (V)
DB1S : 4.1
DB2S : 4.1
DB3S : 4.1 DB5S
DB4S : 4.1
DB5S : 4.1
2.2U
D4841 L4842
DB6S : 4.1
0 1SV308
R4841
3.3K
0.18U
DB6S
L4733 C4734 L4735 C4736 L4739 C4738 D4732
0.22U
10U 820P 10U 820P 0.1 1SV308
C4864
22P
0.001 0.001
0.001 0.001 0.001 0.001 0.001
0.001 0.001 0.001 0.001 0.001 0.001
2 MHz band
L4753 C4754 L4755 C4756 C4758
D4752
L4758
0.22U
15U 100P 15U 100P 0.1 1SV308
C4867
22P
0.001 0.001 0.001 0.001 0.001
0.001 0.001 0.001
4 MHz band
L4773 C4774 L4775 C4776 R4774 C4778
D4772
10U 56P 10U 56P 0 0.1 1SV308
0.001
6 MHz band
L4793 C4795 L4796 C4798 L4799 R4794 C4802 D4792
1.5U
3.3U 120P 3.3U 120P 0 0.1 1SV308
L4794 C4800
L4797
2.7U 27P
3.9U
C4794
180P C4797
180P
0.22U
8 MHz band
10P 10P
C4816 C4821
0.1 5.6U
C4812 L4814 L4817 L4820 R4814 C4829 D4812
5.6U C4822 0.56U
C4817 0 270P 1SV308
18P
18P L4818
L4815 C4827
1U
0.68U
C4823
39P
C4818 150P
220P
82N 680P 680P 82N 0.001 82N 680P 680P
0.001 12 MHz band
10P
C4852
47P 2.2U 1.2U
C4842 L4844 L4847 L4850 R4844 C4860 D4842
C4847 C4853 0.47U 0 0.1 1SV308
L4845 47P 68P C4858
L4848
0.82U
18P
C4848 1.5U
150P C4854
C4863
68P
18P
0.1
560P 0.15U 680P 0.12U 680P
16 MHz band
11-6
14V
C4874
0.1
C4872
0.1
Q4871
LDTA114YE
C4871 D4871 C4873 D4872
0.1
0.1 1SV308 1SV308
R4882 R4883
L4886
2.2K 2.2K 100U
C4883
6.3
10
C4884 L4882
0.1
C4888
0.1
LR-589
D4881
C4882
2.6
Q4881
1SV308 0.1
2SC3356G
C4889 D4883
3.3 0.1
1SV308
L4885
LR-589
Explanatory notes
TX Line
RX Line
Voltage Line
14V
MAIN UNIT(2/9)
8V
DPOFS MAIN UNIT(5/9)
Q4872
LDTC143ZE
DPONS MAIN UNIT(5/9)
Q4883
LDTA114YE
Q4884
LDTC143ZE
D4882
Q4882 L1SS400
LDTA114YE
C4875
DRRF MAIN UNIT(6/9)
0.1
Measuring condition:
(unless otherwise noted)
• Frequency: 12.23 MHz
• Mode: J3E (USB)
• RX: No signal is received.
• TX: No modulation signal is applied.
• Waveforms are measured by
an oscilloscope.
Voltage notation:
TX
RX Unit: Volt
RX