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4-4 OTHER CIRCUITS
4-4-1 SUB-CPU RESET CIRCUIT (CONTROL UNIT)
IC2 is the reset voltage detecting circuit. The output voltage
from the +5 regulator circuit (IC5) is applied to the VDD ter-
minal (IC2, pin 2). IC2 outputs "H" (high) signal to the sub-
CPU (IC6, pin 15) when the VDD terminal's voltage is high-
er than detecting voltage.
IC6 employs the 8-bit CPU.
4-4-2 LCD DISPLAY CIRCUIT (CONTROL UNIT)
The transceiver's LCD display employs 1/4 duty custom
LCD which displays frequency, S-meter, TX power level, etc.
The LCD display is controlled by the sub-CPU (IC6, pins
41–78) directly.
4-4-3 LCD AND KEY BACK LIGHT CIRCUITS
(CONTROL UNIT)
The sub-CPU (IC6) outputs +8 regulator circuit (Q1, Q3, D5)
control signal from pin 2. The voltage from +8 regulator cir-
cuit is applied to the key back light circuit (DS13–DS18,
DS20, DS23) and LCD back light circuit (DS22).
The back light color is also controlled by the sub-CPU via
the color control circuit (Q6, Q7). The back light has 3 colors
(Umber, Green and Yellow).
4-5 POWER SUPPLY CIRCUITS
4-5-1 CONTROL UNIT VOLTAGE LINES
Line
Common 8 V converted from the HV line by the
+8 regulator circuit (Q1, Q3, D5). The output volt-
8V
age is applied to the LCD back light (DS22) and
key back light (DS13–DS18, DS20, DS21, DS23)
circuits.
Common 5 V converted from the HV line by the
+5 regulator circuit (IC5, D4). The output voltage
CPU5V
is applied to the reset circuit (IC2) and buffer
amplifier (Q2).
Description
4-5-2 MAIN UNIT VOLTAGE LINES
Line
The voltage from the external power supply via
HV
the W501 (OPC-465).
The same voltage as the HV line which is con-
trolled by the VCC regulator circuit (Q501). The
VCC
circuit is controlled by the power switch controller
(Q502).
Common 8 V converted from the VCC line by the
8V
+8 regulator circuit (IC504).
Transmit 8 V for VHF band which is the same
voltage as the 8V line controlled by the VT8 reg-
VT8
ulator circuit (Q19, Q22) using the "VTXC" line.
Transmit 8 V for UHF band which is the same
UT8
voltage as the 8V line controlled by the UT8 reg-
ulator circuit (Q20, Q23) using the "UTXC" line.
Common 5 V converted from the HV line by the
5V
+5 regulator circuit (IC503).
Common 5 V converted from the 5V line by the
+5 regulator circuit(Q503, D504). The circuit is
5VS
controlled by the power switch controller (Q502).
Common 8 V converted from the 8 V line by the
VCO8
+8 regulator circuit (Q4).
Common 8 V line which is selected by the
SEL_SW circuit (Q6, Q8). The voltage is applied
V_VCO8
to the VHF VCO (VCO board; Q3, D1, D2) and
buffer amplifiers (VCO board; Q4, Q5).
Common 8 V line which is selected by the
SEL_SW circuit (Q6, Q8). The voltage is applied
to the UHF VCO (VCO board; Q101, D100,
U_VCO8
D101) and buffer amplifiers (VCO board; Q102,
Q103).
Receive 5 V line converted from the 5VS line by
the R5 regulator circuit (Q24). The circuit is con-
R5
trolled by the "R5CTRL" signal from the CPU
(IC505, pin 78).
Receive 5 V line for AM circuit converted from the
5VS line by the AM5 regulator circuit (Q25). The
AM5
circuit is controlled by the "AM" signal from the
CPU (IC505, pin 69).
Receive 5 V line for VHF circuit converted from
the 5VS line by the VHF_R5 regulator circuit
VHF_R5
(Q26). The circuit is controlled by the "RXVHF"
signal from the CPU (IC505, pin 73).
Receive 5 V line for UHF circuit converted from
the 5VS line by the UHF_R5 regulator circuit
UHF_R5
(Q27). The circuit is controlled by the "RXUHF"
signal from the CPU (IC505, pin 74).
Receive 5 V line for 400 MHz circuit converted
from the 5VS line by the 400_R5 regulator circuit
400_R5
(Q28). The circuit is controlled by the "RX400"
signal from the CPU (IC505, pin 67).
Receive 5 V line for 800 MHz circuit converted
from the 5VS line by the 800_R5 regulator circuit
800_R5
(Q29). The circuit is controlled by the "RX800"
signal from the CPU (IC505, pin 66).
4 - 8
Description
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