Icom IC-910H Service Manual page 66

5-5 TRANSMITTER ADJUSTMENTS
ADJUSTMENT ADJUSTMENT CONDITION
• Preset R131, R135, R150, R650 (PA unit) to max. counter clockwise.
PA UNIT 1
• Preset R3, R138, R503 (PA unit) to center position.
PRESETTING
• Preset C154, C659 (PA unit) to center position as illustration at right.
IDLING 1 • Display frequency:
[EUR], [KOR]
CURRENT
[USA-1], [AUS] 146.0000 MHz
(for 144 M)
• Mode
• Transmitting
• Transmitting
2
3 • Transmitting
4 • Display frequency:
(for 430 M)
[EUR], [KOR]
[USA-1], [AUS] 450.0000 MHz
• Mode
• Transmitting
RF PEAK 1 • Display frequency: 440.0000 MHz
• Connect an SSG to P1 on the PA
(for 430 M)
unit via the JIG cable (A) and set as:
Frequency : 10.850 MHz
Level
Modulation : OFF
• Transmitting
• Set an SSG as:
2
Level
• Transmitting
• Connect an SSG to P501 on the PA
(for 144 M) 3
unit via the JIG cable (A) and set as:
Frequency : 10.850 MHz
Level
Modulation : OFF
• Display frequency: 146.0000 MHz
4
• Set an SSG as:
Level
• Transmitting
IF PEAK 1 • Display frequency: Any
• Mode
• MIC gain
• Connect an audio generator to
[MIC] connector and set as:
Frequency
Level
• Transmitting
CARRIER 1 • Display frequency: Any
• Mode
SUPPRESSION
• Mic gain
• Apply no audio signals to [MIC]
connector.
• Transmitting
2 • Mode
• Transmitting
3 • Repeat step 1, step 2 several times.
UNIT
PA
145.0000 MHz
: CW
435.0000 MHz
: CW
Rear
panel
: 18 mV* (–22 dBm)
: 0.79 µV* (–2 dBm)
: 18 mV* (–22 dBm)
: 0.79 µV* (–2 dBm)
MAIN
: USB
: Center
: 1.5 kHz
: 2 mVrms
MAIN
: USB
: Minimum
: LSB
MEASUREMENT
LOCATION
Connect an ammeter At the point where the
(3 A) between power TX current increases
supply and the IC- 0.5 A.
910H.
At the point where the
TX current increases
1.0 A as step 1.
At the point where the
TX current increases
0.5 A as step 2.
At the point where the
TX current increases
1.0 A.
Connect an RF
power meter to [UHF
ANT] connector.
Connect an RF
Refer page 5-16 software adjustment 6.
power meter to [VHF
ANT] connector.
Connect an RF volt-
meter to check point
J51 via the JIG cable
(B).
Minimum carrier level
Connect a spectrum
analyzer to check
point J51 via the JIG
cable (B).
5 - 8
ADJUSTMENT
POINT
VALUE
UNIT
PA
Maximum output PA
power
Maximum output PA
power
Maximum level MAIN
MAIN
ADJUST
R131
R135
(R138)
R650
R150
L1, L2
C154
C659
L2, L3
R206,
R215