Icom IC-R10 Service Manual

.
1st
VCO
Receive
frequency
[MHz]
VCO
select
signal
VCO
components
VCO
frequency
[MHz]
0.5-
199.9999
VII
Q621,
Q622,
D621
429.6
-
629.0999
200.0-
533.2999
V12
Q641,
D641
629.1
-
799.9999
533.3
-
609.9999
V13
Q661,
D661,
D662
800.0
-
876.6999
610.0- 895.7999
VII
Q621.Q622,
D621
343.3
-
629.0999
895.8-
999.9999
V12
Q641,
D641
629.1
-733.2999
1000.0-1058.1999
VII
0621,0622,
D621
570.9
-
629.0999
1058.2-1229.0999
V12
0641,
D641
629.1
-799.9999
1229.1
-
1300.0000
V13
0661,
D661,
D662
800.0-
870.9000
4-2-5
2ND LO
PLL
CIRCUIT
(MAIN
UNIT)
The
2ND LO PLL
circuit
generates
the 2nd
LO frequency
for
the
main band
(receive signal) and
sub-band
(band
scope
and
SIGNAVI
functions).
Signals
from the
2ND
VCO
unit pass
through
the
buffer
amplifier (0531
for main
band, 0551
for the
sub-band)
and
are
applied
to
the
PLL
1C
(IC501;
pin 2
and pin 19
respectively)
and
prescaled
in the
PLL
1C
based
on the
divided
ratio (N-data).
The PLL 1C
detects
the out-of-step
phase
using
the
reference
frequency
and outputs
it from
pins 8
and
13. The
output
signal from
pin 8 is
passed
through
the
loop
filter (R51
1 ,
R51
2,
R51
4,
C51
1 ,
C51
2),
and
is
then
applied
to
the
2ND VCO
circuit for
the main band
(2ND
VCO unit)
via the
21 LV
terminal (2ND
VCO unit; J601)
as
the
lock voltage.
The output
signal from
pin
13
is passed
through
the loop
filter
(R521-R523, C521,
C522),
and is
then
applied
to
the
2ND VCO
circuit
for the sub-band
(2ND
VCO
unit) via the
22LV
terminal (2ND
VCO
unit;
J601
)
as
the
lock voltage.
band
(0411)
after
being
amplified
at
the
buffer
amplifier
(0552).
The
switching
transistors
(0601
and
0701)
shift the
oscillating
frequencies
via the
“IFH"
signal from
the RF unit.
4-3
POWER
SUPPLY
CIRCUITS
VOLTAGE
LINE
(LOGIC
UNIT)
Line
Description
HV
The voltage
coming
from the
external DC
jack.
VCC
The same
voltage as
the installed
battery cells
or
HV line
passed through
the
charge control
circuit
(Q101.D104).
+3CPU
Common 3
V for the
CPU (ICl)
produced at
the
+3CPU
regulator 1C
(IC81). The
circuit
outputs
the voltage
regardless
of the
power
ON/OFF
condition.
+3S
Common
3
V
converted from
the VCC
line
by
the
+3S
regulator
circuit
(Q121,
Q122)
using a
control
signal (+3SC)
from the
CPU.
+3C
Common 3
V converted
from the
VCC line by
the
+3C
regulator
circuit
(Q111, Q112)
using a
control
signal
(3LCON)
from the CPU.
+3L
Common 3
V
converted from
the VCC line by
the
+3L regulator circuit
(Q91
,
Q92)
using
a
control
signal
(3LCON)
from the CPU.
+15
Common
15 V
converted
from the +3L
line by
the DC-DC
convertor iC
(ICl
51).
4-2-6
VXO
CIRCUIT
(MAIN
UNIT)
The VXO
(Variable
Crystal
Oscillator)
circuit
(IC501, X501
and
D501)
generates a 12.8
MHz
2nd
reference frequency.
The 2nd
reference
frequency
is
stabilized
within
the
temperature range
-10°C
(+14°F) to
+50°C
(+122°F).
For
tuning
the 100
Hz
frequency step,
the VXO
circuit
changes
the
capacitance
of a
varactor
diode (D501
)
via
the
voltage
of the
“VXO”
line
from the
CPU (LOGIC
unit; IC1),
and
controls
the 2nd
reference frequency.
4-2-7
2ND
VCO
CIRCUIT
(2ND VCO
UNIT)
The
2ND
VCO unit
contains two
VCO
circuits for the
main
band
and
sub-band.
The VCO
circuit
for the main
band
consists
of
0602,
0604 and
D601
,
and
the VCO
circuit
for
the sub-band
consists of
Q702,
0704
and
D701.
The
oscillated
signal
is
amplified at
the buffer
amplifiers
(0603
for the
main
band, 0703
for the
sub-band). Then
the
2nd
LO
signal
for the
main band
is applied to the
2nd
mixer
(ICl
1
,
pin
3)
via the
buffer amplifier
(0532),
and the
2nd LO
signal
for the sub-band is
input to
the 2nd
mixer for the
sub-
4-5

Icom IC-R10 Specifications

General

Brand	Icom
Model	IC-R10
Category	Receiver
Language	English