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4-3
• FILTER, TX AMPLIFIER AND LPF CIRCUITS
LPF
BPF
BPF
BPF
BPF
BPF
BPF
LPF
LPF
LPF
LPF
LPF
LPF
PWR
AMP
DRIVE
AMP
DRIVE
PRE
HPF
SWR
DET
LPF
LPF
LPF
RF
AMP
BPF
MAIN-A UNIT
0.03-1.59 MHz
1.60-2.49 MHz
2.50-3.99 MHz
4.00-5.99 MHz
6.00-8.99 MHz
9.00-12.99 MHz
13.00-19.99 MHz
20.00-29.99 MHz
1.6-2.3 MHz
2.3-3.3 MHz
3.3-4.9 MHz
7.0-10.0 MHz
10.0-14.5 MHz
14.5-21.0 MHz
RX
TX
3
0
0
4
Q
Q4002
YGR
AMP
IC1101
21.0-30.0 MHz
4.9-7.0 MHz
Q6851
Q4006,
Q4007
From the 2nd
TX IF circuits
D1131
2
1
1
1
D
0
2
1
1
D
D1121
D1122
D1123
D1124
D1125
D1126
D1127
D1111
RL5011
RL5021
RL5031
RL5041
RL5051
RL5061
RL5071
RL5081
RL5022
RL5032
RL5042
RL5052
RL5062
RL5072
RL5082
RL5001
D5001
D5002
PA-A UNIT
RL5012
D1113
D1106
D1114
D1115
D1116
D1118
D1119
D1117
D1133
• 2ND AND 1ST TX IF CIRCYUIT
IF
AMP
BPF
XTAL
BUFF
15 kHz
FI1401
D1813
Q1409
IC1401
Q1401
2nd TX LO signal
1st TX LO signal
From the 3rd
TX IF circuits
To the filter
circuits
D1401
D1402
D1404
D1407
D1410
64.455MHz 1st TX IF
TX frequency
D1812
2ND TX IF CIRCUIT (MAIN-A UNIT)
The 2nd TX IF signal from the 3rd TX IF circuits is applied
to the 2nd TX IF mixer (D1812, D1813), to be mixed with
the 2nd TX LO signal, resulting in the 64.455 MHz 1st TX IF
signal.
The 1st TX IF signal is passed through the 1st TX IF filter
(FI1401), amplified by the 1st TX IF AMP (Q1409), and then
applied to the 1st TX IF circuits.
1ST TX IF CIRCUIT (MAIN-A UNIT)
The 1st TX IF signal from the 2nd TX IF circuits is applied
to the 1st TX IF mixer (IC1401), to be mixed with the 1st TX
LO signal, resulting in the TX signal (TX frequency itself).
The converted TX signal is applied to the filter circuits,
through the buffer (Q1401).
FILTER CIRCUIT (MAIN-A UNIT)
The TX signal from the 1st TX IF circuits is passed through
the one of BPFs, depending on the operating frequency, to
remove unwanted signals contained in the TX signal.
The filtered TX signal is amplified by the YGR AMP
(IC1101), and then applied to the PA-A UNIT.
TX AMPLIFIER CIRCUIT (PA-A UNIT)
The TX signal from the MAIN-A UNIT is applied to the RF
AMP (Q4002), through the LPF (L4002, C4008, C4014).
The amplified TX signal is sequentially amplified by the pre-
drive AMP (Q4003), drive AMP (Q6851), and power AMP
(Q4006, Q4007).
The amplified TX signal is applied to the PA-A UNIT.
LPF CIRCUIT (PA-A UNIT)
The amplified TX signal from the power AMP (Q4006,
Q4007) is passed through one of LPFs, depending on the
transmitting frequency, to remove harmonic components
contained in the TX signal.
The filtered TX signal is applied to the antenna, through the
TX/RX line SW (RL5001) and SWR detect circuit (D5001,
D5002).