Pll Adjustments; Frequency Adjustment - Icom IC-910H Service Manual

5-2 PLL ADJUSTMENTS

ADJUSTMENT ADJUSTMENT CONDITION
30.2 MHz 1 • Display frequency: Any
• Receiving
LEVEL
1 • Display frequency: Any
REFERENCE
• Receiving
FREQUENCY
2 This adjustment must be performed
at 5 minutes later after power ON.
1 • Display frequency: 173.9800 MHz
144M LOCK
VOLTAGE • Mode
• Receiving
2 • Display frequency: 136.0200 MHz
• Receiving
3 • Display frequency: 155.0000 MHz
• Receiving
440M LOCK 1 • Display frequency: 479.9800 MHz
VOLTAGE • Mode
• Receiving
2 • Display frequency: 420.0200 MHz
• Receiving
3 • Display frequency: 450.0000 MHz
• Receiving
MAIN BFO 1 • Display frequency: Any
LEVEL • Mode
• Receiving
SUB BFO 2 • Sub display freq. : Any
LEVEL • Mode
• Receiving

5-3 FREQUENCY ADJUSTMENT

ADJUSTMENT ADJUSTMENT CONDITION
1 • Display frequency: Any
FM TX-LO
• Mode
FREQUENCY
• Disconnect P501, P502 (PA unit)
from J51 and J52 on the MAIN unit.
• Apply no audio signals to [MIC]
connector.
• Transmitting
After adjustment, connect P501, P502 (PA unit) to J51, J52 on the MAIN.
UNIT
: USB
: USB
:USB
:USB
UNIT
MAIN
: FM
From The N3UJJ.COM Document Library From The N3UJJ.COM Document Library
MEASUREMENT
LOCATION
PLL Connect an RF volt-
meter or spectram
analyzer to check
point J541.
PLL Connect an RF volt-
meter or spectram
analyzer to check
point P551.
Connect a frequency
counter to check
point P551.
PLL Connect a digital
multimeter or oscillo-
scope to check point
CP100.
Connect an RF volt-
meter to check point
P251.
PLL Connect a digital
multimeter or oscillo-
scope to check point
CP300.
Connect an RF volt-
meter to check point
P421.
PLL Connect an RF volt-
meter to check point
P601.
PLL Connect an RF volt-
meter to check point
P701.
MEASUREMENT
LOCATION
Connect a frequency
counter to check
point CP51.
5 - 2
ADJUSTMENT
VALUE
UNIT
–10 dBm (or more than PLL
–11.5 dBm, when R570
is in maximum posi-
tion.)
Maximum level PLL
(–13 dBm to –7dBm)
60.400000 MHz
2.7 V PLL
0.6 V to 1.6 V
–10 dBm to –4 dBm
3.4 V PLL
0.5 V to 1.5 V
–16 dBm to –10 dBm
–11 dBm to –5 dBm PLL
–11 dBm to –5 dBm PLL
ADJUSTMENT
VALUE
UNIT
10.85000 MHz MAIN
POINT
ADJUST
R570
Adjust in
sequence
L551, L552
s e v e r a l
times.
The trimmer
capacitor of
X512.
L193
Verify
Verify
C402
Verify
Verify
Verify
Verify
POINT
ADJUST
L255