Icom IC-910H Service Manual page 28

TRANSMITTER ADJUSTMENTS (continued)
ADJUSTMENT ADJUSTMENT CONDITION
IF TOTAL 1 • Display frequency: Any
GAIN • Mode
• MIC gain
• Disconnect P501 (PA unit) from J51
on the MAIN unit.
• Connect an audio generator to
[MIC] connector and set as:
Frequency
Level
• Transmitting
After adjustment, connect P501 (PA unit) to J51 on the MAIN.
TOTAL GAIN 1 • Display frequency:
(for 144 M) [EUR], [KOR]
[USA-1], [AUS] 146.0000 MHz
• Mode
• RF power
• MIC gain
• Connect an audio generator to
[MIC] connector and set as:
Frequency
Level
• Transmitting
(for 430 M) 2 • Display frequency:
[EUR], [KOR]
[USA-1], [AUS] 450.0000 MHz
• Transmitting
Ic APC 3 • Display frequency: 146.0000 MHz
• Mode
• Connect CP1631 (MAIN unit) to
GND.
• RF power
• Mic gain
• Connect an audio generator to
[MIC] connector and set as:
Frequency
Level
• Transmitting
After adjustment, disconnect CP1631 (PA unit) from GND on the MAIN.
DRIVE LEVEL 1 • Display frequency: 146.0000 MHz
• Mode
• RF power
• Mic gain
• Disconnect P501 (PA unit) from J51
on the MAIN unit.
• Connect an audio generator to
[MIC] connector and set as:
Frequency
Level
• Transmitting
2 • Mode
• CW paddle
• Connect a keyer to the [KEY] jack.
• Key down (transmitting)
After adjustment, connect P501 (PA unit) to J51 on the MAIN.
LO leak must be performed after software adjustment (7) "TX POWER/METER".
LO LEAK 1
(for 144 M)
• Display frequency:
[EUR], [KOR]
[USA-1], [AUS] 148.0000 MHz
• Mode
• RF power
• MIC gain
• Transmitting
MEASUREMENT
UNIT
MAIN
: USB
: Center
: 1.5 kHz
: 2 mVrms
Rear
145.0000 MHz panel
: USB
: Maximum
: Center
: 1.5 kHz
: 2 mVrms
435.0000 MHz
Rear
: USB panel
: Maximum
: Center
: 1.5 kHz
: 20 mVrms
MAIN
: USB
: Maximum
: Center
: 1.5 kHz
: 20 mVrms
: CW
: OFF
Rear
146.0000 MHz panel
: USB
: Minimum
: Center
5 - 10
LOCATION
Connect an RF volt-
meter to check point
J51 via the JIG cable
(B).
Connect an RF
power meter to [VHF
ANT] connector.
Connect an RF
power meter to [UHF
ANT] connector.
Connect an ammeter
(30A) between power
supply and the IC-
910H.
Connect an RF volt- Read the RF voltmeter
meter to check point indication.
J51 via the JIG cable
(B).
Same level as step 1
Connect an RF Minimum output power
power meter to [VHF
ANT] connector.
ADJUSTMENT
POINT
VALUE
UNIT ADJUST
–22 dBm MAIN
50 W PA
37.5 W
23 A MAIN
MAIN
PA
R3
R503
R3
R1613
Verify
R202
R504