Icom IC-04A Service Manual page 21

6-3
PLL
ADJUSTMENT
TEST INSTRUMENTS REQUIRED
(1)
VOLTAGE REGULATED
POWER
SUPPLY
!2)
RF
POWER
METER (TERMINATED
TYPE)
(5)
VOLTMETER
(12)
FREOUENCY COUNTER
ADJUSTMENT
ADJUSTMENT
CONDITIONS
MEASUREMENT
VALUE
ADJUSTMENT
POINT
UNIT LOCATION UNIT
ADJUST
LOCK
VOLTAGE
iC)
1
• Operating frequency:
430.
OOOMHz
440.
OOOMHz
(#05)
•
Transm
it
mode
PLL Connect
the voltmeter to
R250.
Loss than
1 .
5V
VCO
C702
2
• Transmit
mode
•
Simplex
mode
Less than
1
.
5V
C705
3 •
Operating frequency:
439.
990MHz
449.990MHz
(#05)
• Receive
mode
Less than
3.
5V
Verify
REFERENCE
FREQUENCY
(D)
1
•
Operating frequency:
430.
OOOMHz
440.000MHz (#05)
•
Simplex
mode
•
Receive
mode
PLL Connect
the frequency
counter to
cathode
of
D208.
408.2MHz
PLL C298
2
•
RF
OUTPUT POWER
SELECTOR
SWITCH:
LOW
•
Transmit
mode
408.2MHz
Verify
6-4
RECEIVER
ADJUSTMENT
TEST INSTRUMENTS REQUIRED
(1
)
VOLTAGE REGULATED
POWER
SUPPLY
(3)
RF
VOLTMETER
(4)
AC
MILLI-VOLTMETER
(7)
DISTORTION METER
(8)
SINAD
METER
(11)
SIGNAL
GENERATOR
(12)
FREOUENCY COUNTER
ADJUSTMENT
......
ADJUSTMENT CONDITIONS
MEASUREMENT
VALUE
ADJUSTMENT
POINT
UNIT
LOCATION
UNIT
1
•
Operating frequency:
435.000MHz
445.000MHz
(#05)
•
Receive
mode
PLL Connect
the
RF voltmeter
to
cathode of D208.
More
than
450mV
Bj
1
•
Operating frequency:
435.
OOOMHz
445.000MHz
(#05)
•
Receive
mode
PLL Loosely couple the frequency
counter
to
X201
.
21.345MHz
±750Hz
22.695MHz (#
05)
Verify
SENSITIVITY
(G)
• Operating frequency:
435.
OOOMHz
445.000MHz (#05)
•
Receive
mode
•
SOUELCH CONTROL:
Max. counterclockwise
•
Apply
an
RF
signal to
ANTENNA
CON-
NECTOR.
Level:
OApV
Dev.
:
±3.
5kHz Mod.: IkHz
TOP
PANEL
Connect
the
SINAD
meter
to
the
EXTERNAL
SPEKER
JACK
with an 8Q
speaker.
i
Maximum
level
PLL
L206-
L208
2
•
Operating frequency:
435.
OOOMHz
445.000MHz (#05)
Maximum
level L206.L207
Note:
Repeat
steps
1
and
2
several times
until
the
measured
value
is
at
maximum.
AF
OUTPUT
(Hj
•
Operating frequency:
435.000MHz
445.000MHz
(#05)
•
Receive
mode
• Apply an
RF
signal to
the
ANTENNA
CONNECTOR.
Level: I0/<V
Dev.
:
±3.
5kHz Mod.
:1kHz
TOP
PANEL
Connect the
AC
milli-volt-
meter and
distortion
meter
to the
EXTERNAL SPEAKER
JACK
with
an 8S
speaker.
More than
2.0V rms
at
10%
distortion.
Verify
S/RF
INDICATOR
(1)
•
Operating frequency: 435.000MHz
445.000MHz (#05)
• Receive
mode
•
Apply an
RF
signal
to the
ANTENNACON-
NECTOR
Level: 2.5jtrV
FRONT
PANEL
S/RF INDICATOR.
8
dots PLL R221
TIGHT
SOUELCH
SENSITIVITY
(
J
)
• Operating frequency:
435.000MHz
445.
OOOMHz
(#05)
• Receive
mode
•
Apply an
RF
signal to
the
ANTENNA
CON-
NECTOR.
Level:
0.
4/iV Dev.
:
±3.
5kHz Mod.
: 1
kHz
TOP
PANEL
Connect
the
8Q
speaker
to
the
EXTERNAL SPEAKER
JACK.
Squelch opens.
Verify
6-3