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3-7
TX AMPLIFIER CIRCUIT (MAIN AND PA UNITS)
The TX signal from the band fi lter circuit is applied to the
YGR AMP (IC3021), through the 3 dB attenuator (R3022 to
R3024).
The amplifi ed signal is passed through the 72 MHz LPF
(L3014, C3015 to C3017), or the 124 MHz HPF (L3012,
L3013, C3012 to C3014). The fi ltered signal is passed
through two attenuators (3 dB: R3011 to R3013 and 6 dB:
R101 to R103), and then sequentially amplifi ed by the RF
AMP (Q101), pre-drive AMP (Q102) and drive AMP (Q251).
• While operating on the HF, 50 MHz and 70 MHz bands
The amplifi ed signal is applied to the power AMP (Q301
and Q302), through the diplexer (L411, C413, C513, C514,
C515). The amplifi ed signal is passed through the TX/RX SW
(RL801) and one of the LPFs, depending on the operating
band, to remove harmonic components.
The fi ltered signal is applied to the antenna connector
([ANT1]: J1) through the power and SWR detect circuit (D961
and D962).
• While operating on the 144 MHz and 430 MHz bands
The amplifi ed signal is applied to the power AMP (Q501),
through the diplexer (L203, L204, C214, C216, C262, C266).
The amplifi ed signal is passed through another diplexer
(L411, C413, C513, C514, C515), which separates the band
signal.
- 144 MHz band signal
The TX signal is passed through the TX/RX SW (RL531) and
LPF (L541 to L543, C542 to C547).
- 430 MHz band signal
The TX signal is sequentially passed through the TX mute
SW (D431 and D432), TX/RX SW (D422 to D424), another
mute SW (D433 and D434) and HPF (L441, L442, C441 to
C444).
The fi ltered 144 MHz/430 MHz band signal is applied to the
antenna connector ([ANT2]: J2), through the LPF (L591 to
L593, C591 and C592), which removes harmonic compo-
nents, and the SWR detect circuit (D651 and D661).
LPF
LPF
DIPLEXER
DRIVE
AM P
D961,D962
PWR/SWR
DET
TX/RX
SW
TX/RX
SW
LPF
HPF
DRIVE
PRE
TX/RX
SW
PWR
AMP
ANTENNA
ATT
LPF
ANTENNA
PWR
AMP
Q301,Q302
LPF
PWR/SWR
DET
LPF
LPF
LPF
LPF
DIPLEXER
RF
AMP
MUTE
MUTE
144 MHz BAND ->
7.3-14.35MHz
144/430 MHz BAND ->
fc=270M
PA UNIT
fc=200M
21.45-33.0MHz
14.35-21.45MHz
fc=700M
6dB
144/430MHz
HF/50MHz/70MHz
HF/50MHz/70MHz BAND ->
From the 1st TX IF circuit
To the RX circuit
To the
RX circuit
To the
RX circuit
0.03-2.0MHz
2.0-4.0MHz
4.0-7.3MHz
33.0-74.8MHz
Q251
Q102
Q101
D422 to D424
Q501
D433,D434
D431,D432
D651,D661
430 MHz BAND ->
HPF
LP F
YGR
AMP
IC3021
AT T
ATT
3dB
fc=72MHz
fc=124MHz
3dB
• TX AMPLIFIER CIRCUIT