Icom IC-78 Service Manualvice Man page 20

TRANSMITTER ADJUSTMENTS—continued
ADJUSTMENT ADJUSTMENT CONDITION
CARRIER 1 • Display frequency: 12.23000 MHz
SUPPRESSION • Mode
• Mic gain
• Apply no audio signals to [MIC]
connector.
• Transmitting
AM 1 • Display frequency: 12.23000 MHz
• Mode
CARRIER
• RF power
• Mic gain
• R2321 (MAIN unit): Center
• R2385 (MAIN unit): Center
• Apply no audio signals to [MIC]
connector.
• Transmitting
AM 1 • Display frequency: 12.23000 MHz
• Mode
MODULATION
• RF power
• Mic gain
• R2385 (MAIN unit): 9 o'clock
• Connect an audio generator to
[MIC] connector and set as:
Frequency
Level
• Transmitting
2 • Set an AG as:
Frequency
Level
• Transmitting
CW 1 • Display frequency: 12.23000 MHz
• Mode
CARRIER
• RF power
• Connect a keyer to the [KEY] jack.
• Key down (transmitting)
MEASUREMENT
UNIT
Rear
: USB panel
: Minimum (0)
Rear
: AM panel
: Maximum (H)
: Minimum (0)
Rear
: AM panel
: Maximum (H)
: Center (50)
: 1 kHz
: 30 mVrms
: 1 kHz
: 3 mVrms
MAIN
: CW
: Maximum (H)
5 - 6
LOCATION
Connect a spectrum Minimum carrier level
analyzer to the [ANT]
connector through an
attenuator.
Connect an RF
power meter to [ANT]
connector.
Connect a modula- 70% modulation
tion analyzer to the
[ANT] connector
through an attenua-
tor.
90% modulation
Connect an oscillo- Adjust as follows:
scope to CP3701 and
[ANT] connector.
10 msec.
ADJUSTMENT
POINT
VALUE
UNIT
MAIN
40 W MAIN
MAIN
MAIN
Keying (CP3701)
ADJUST
R2303
R1730
R2321
R2385
R3703