Icom IC-725 - Specific Adjustment Procedures

6-2
PLL
ADJUSTMENT
ADJUSTMENT
ADJUSTMENT
CONDITIONS
MEASUREMENT
VALUE
ADJUSTMENT
POINT
UNIT
LOCATION
UNIT
ADJUST
REFERENCE
FREQUENCY
1
•
Displayed
frequency: 14.10000 MHz
•
Mode
: USB
•
Receiving
PLL
0
Terminate P4 to
ground with a 50 Q
resistor.
Connect the RF
voltmeter
to P4.
Pre-set to
center.
PLL
Cl 34
2
Maximum level
(More
than
-F3 dBm)
L38,
L39
3
Connect the
frequency counter
to P4.
61.4400 MHz
L35
H
After
adjustment, remove
the resistor from P4 and re-plug P4.
DOS
CLOCK 1
•
Displayed frequency:
14.10000 MHz
•
Mode :
USB
•
Receiving
DDS Connect the
frequency counter
to
IC4 pin 1
1
or IC5
pin 11.
5.24288 MHz
DDS
Cl
DOS LOOP 1
•
Displayed frequency:
14.12650 MHz
•
Mode
: AM
•
Receiving
PLL Connect the
oscilloscope to R133
(rear panel side).
1.0 V DC
PLL
L30
2
•
Displayed
frequency: 14.12649 MHz
Approx. 2.0 V DC
Verify
1ST LO
LOCK
VOLTAGE
1
•
Displayed frequency: 7.99999 MHz
•
Mode
‘
: USB
•
Receiving
PLL
Connect the
oscilloscope to R77.
(shielding
case
side)
6.5 V DC
PLL C35
2
•
Displayed frequency:
14.99999 MHz
6.5 V DC
C46
3
•
Displayed
frequency:
21
.99999
MHz
6.5 V DC
C59
H
•
Displayed
frequency: 33.00000
MHz
7.5 V DC
C70
5
•
Displayed
frequencies
:
0.50000
MHz, 8.00000 MHz,
15.00000
MHz and 22.00000 MHz
More than
2.0 V DC
Verify
1STLO
OUTPUT
LEVEL
1
•
Displayed frequency:
14.10000 MHz
•
Mode : USB
•
Receiving
PLL Terminate P5 to
ground with a 50 O
resistor.
Connect the RF
voltmeter to P5.
More than
0
dBm
Verify
2 After
adjustment, remove the
resistor from
P5
and re-plug
P5.
RIT
1
•
Displayed frequency:
14.10000 MHz
•
Mode : USB
•
Set the
signal generator;
Level :
50
pV
(-73 dBm)
Modulation
:
OFF
• [RIT] switch : ON and
OFF
•
Receiving
Top
cover
Speaker
Pre-set to center.
Front
panel
[RIT]
control
2
Same
tone pitch
on
both conditions.
PLL R70