Icom IC-7400, Service Manual, Page: 18 / 92

5 - 2
5-2 PLL ADJUSTMENTS
REFERENCE
FREQUENCY
LPL LOCK
VOLTAGE
VCO LOCK
VOLTAGE
1LO
OUTPUT
LEVEL
3LO
OUTPUT
LEVEL
MARKER
OUTPUT
LEVEL
ADJUSTMENT
ADJUSTMENT ADJUSTMENT CONDITION
MEASUREMENT
VALUE
POINT
UNIT LOCATION UNIT ADJUST
1
2
1
1
2
3
4
1
1
1
• Displayed freq. : Any
• Preset R1032 (RF unit) to the cen-
ter position.
• Preset L1902 (RF unit) approxi-
mate 1.5 mm downside from top of
the coil’s case.
• Receiving
• Receiving
• Displayed freq. : 0.030000 MHz
• Mode
: USB
• Receiving
• Displayed freq. : 7.999999 MHz
• Mode
: USB
• Receiving
• Displayed freq. : 21.999999 MHz
• Mode
: USB
• Receiving
• Displayed freq. : 39.999999 MHz
• Mode
: USB
• Receiving
• Displayed freq. : 60.000000 MHz
• Mode
: USB
• Receiving
• Displayed freq. :
0.500000 MHz, 7.999999 MHz
8.000000 MHz, 21.999999 MHz
22.000000 MHz, 39.999999 MHz
40.000000 MHz, 50.000000 MHz
54.000000 MHz, 144.000000 MHz,
148.000000 MHz
• Receiving
• Displayed freq. : Any
• Mode
: USB
• Receiving
• Displayed freq. : 14.100000 MHz
• Mode
: CW
• Marker : ON
• Receiving
RF
RF
RF
RF
RF
FRONT
Connect an RF volt-
meter to the check
point P1901.
Connect a frequency
counter to the check
point P1901.
Connect a digital
multimeter or oscillo-
scope to the check
point CP1101 (LV1).
Connect a digital
multimeter or oscillo-
scope to the check
point CP1801 (LV2).
Connect an RF volt-
meter to the check
point CP1500.
Connect an RF volt-
meter to the check
point CP1601.
Display
Maximum level
(0 dB or more)
64.000000 MHz
1.0 V
4.0 V
–7 dBm or more
–25 dBm or more
S3 or more
(S-meter level)
RF
RF
RF
L1903,
L1904
,
L1901
(L1902, R1032
for critical
adjustment)
C1303
C1208
C1228
C1248
C1268
Verify
Verify
Verify