Icom IC-T81E - Port Allocations

4 - 6
• PLL circuit
Shift register
Prescaler
Phase
detector
Loop
filter
Programmable
counter
Programmable
divider
X1
13.8 MHz
Q311,
Q312,
D302,
D311
144 MHz VCO
50MHz RX VCO
Buff.
D802,
D803
Q807
Q313,
D312
3
4
5
PSTB
IC801 (PLL IC)
CLK
DATA
to transmitter circuit
to 1st mixer circuit
(IC601, pin 1)
16
13
19
Q301,
Q302,
D301
Q811,
Q812
VCO BOARD
8
Loop
filter
Q804,
Q805
50 MHz TX VCO
Buff.
Q342
Buff.
Q313
2
to transmitter circuit
Q321,
Q322,
D321,
D322
430 MHz VCO
Q341, D341
TX/RX
SW
Buff.
Q822
Amp.
Buff.
Q323
D804,
D805
to transmitter circuit
TX/RX
SW
Q823
Amp.
TUNE
CTRL
Q803
"LOCKV" signal
to the IC1, pin 5
IC802 (PLL IC)
3
4
5
CLK
DATA
STB
1
5
16
1200MHz VCO
Q350,
D351,
D352
Buff.
Q351,
Q354
D804,
D805
TX/RX
SW
Q823
Amp.
to transmitter circuit
Buff.
Q816
Pin Port
Description
number name
4
5
6
7
11
12
13
14
Q1
Q2
Q3
Q4
Q8
Q7
Q6
Q5
Outputs VHVCO3 regulator control
signal.
Outputs VLVCO3 regulator control
signal.
Outputs 6MVCO3 regulator control
signal.
Outputs VCO shift signal for SHF,
UHF, 144 MHz and 50 MHz.
Outputs 12VCO3 regulator control sig-
nal.
Outputs UHVCO3 regulator control
signal.
Outputs UHF TX and RX regulator
control signal.
Outputs 1200 MHz TX and RX regula-
tor control signal.
Pin Port
Description
number name
4
6
7
11
12
13
Outputs 300 MHz band RX regulator
control signal.
Outputs AM mode regulator control
signal.
Outputs WFM band RX switching con-
trol signal.
Outputs WFM band RX regulator con-
trol signal.
Outputs 50 MHz band TX and RX reg-
ulator control signal.
Outputs VHF band TX and RX regula-
tor control signal.
Q1
Q3
Q4
Q8
Q5
Q6
4-5-2 I/O EXPANDER IC (RF UNIT; IC3)
4-5 PORT ALLOCATIONS
4-5-1 I/O EXPANDER IC (RF UNIT; IC2)