TKR-D710
15
2-10. Other circuit
■
EEPROM
The EEPROM (IC802) has a data capacity of 2Kbit. It
stores the tuning data in frequency adjustment.
■
Temperature sensor
The temperature sensor (IC800) monitors temperature
around the VCTCXO (X500).
■
I/O expander
The I/O expander IC (IC805) controls power sources, fan,
analogue switches, and the transmit power control circuit.
IC805 is controlled by the MCU which is in the Control unit
(X53-458).
■
Electronic volume control IC
The Electronic volume control IC (IC804) adjusts the
modulating signal, center frequency of the front-end BPF,
and the power of the RF fi nal amplifi er. IC804 is controlled
by the MCU which is in the Control unit.
3. Final unit
The RF fi nal amplifi er unit (X45-401) amplifi es the trans-
mitter power to a specifi ed level.
This unit consists of the following circuits:
(1) Driver and Final power amplifi er circuit
(2) CM coupler circuit
(3) Filter circuit
(4) APC circuit
(5) High temperature detector circuit
(6) FAN action control circuit
(7) AVR circuit
3-1. Driver and Final power amplifi er circuit
The transmit signal from the TX IN terminal CN1 of the
Final unit (X45-401) is amplifi ed by Q1, Q2 and Q3, and is
passed to the final stage Q4. The signal amplified by the
fi nal stage Q4 passes through the CM coupler circuit and
fi lter circuit, and is then fed to the antenna.
80C_1
Ripple Filter
Ripple Filter
Ripple Filter
15V DC/DC
IC701
SW
RXC
Q700,Q701
SW
RXC
Q705,Q706
SW
SBC
SB
Q702,Q703
CN701
+B
from Final unit
(X45-401 A/3)
+B,SB
to Control unit
(X53-458)
3V AVR
IC704
3.3V AVR
IC703
Ripple Filter
80C
80C_2
150C_1
150C_2
80R
5V AVR
IC700
8V AVR
IC702
50C
50R
30R
33C
CN700
Fig. 11 AVR circuit
Fig. 12 Driver and Final power amplifi er circuit
CN801
CN1
PLIM
FDT
8TC
FAN
ASWC
RAMP
DC AMP
IC202(A/2)
TX ANT
LPF
CM coupler
Vcont
REV DET
FW DET
Auto power control
+B
80T
80T
FW DET
D3
PRE AMP
IC201(A/2)
Limiter AMP
IC201(B/2)
Drive AMP
Q1
Drive AMP
Q2
Final AMP
Q4
Drive AMP
Q3
Temp1
TH201
Buffer AMP
IC202(B/2)
REV DET
D4
CIRCUIT DESCRIPTION
Summary of Contents for TKR-D710
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