![background image](http://html.mh-extra.com/html/icom/id-800h/id-800h_service-manual_611672024.webp)
ADJUSTMENT
ITEM
ADJUSTMENT CONDITION
OPERATION
POWER SUPPLY
CONNECTIONS
• Connect 5.0 V DC power supply to pin 29 ( ) and pin 30 ( ) of J301.
• Connect 8.0 V DC power supply to pin 28 ( ) and pin 30 ( ) of J301.
ENTERING
ADJUSTMENT MODE
• Connect the pin 14 of J301 to GND to enter the adjustment mode.
CODEC
FREQUENCY
1
• Connect the frequency counter to CP101 through a
capacitor (1000 pF).
• Adjust C102 to set to 16.38400 MHz ±10 Hz.
MODEM
FREQUENCY
1
• Connect the frequency counter to CP216 through a
capacitor (1000 pF).
• Adjust C207 to set to 2.457600 MHz ±3 Hz.
MODURATION
OUTPUT LEVEL
1
• Connect the pin 1 of J301 to GND to enter the
transmit mode.
• Connect the oscilloscope to pin 21 of J301.
• Adjust R264 to set to 350 mVp-p ±10 mV.
2
• Disconnect the pin 1 of J301 from GND after the adjustment to exit the transmit mode.
EXITING
ADJUSTMENT MODE
• Disconnect the pin 14 of J301 from GND to exit the adjustment mode.
5-2 CODEC BOARD ADJUSTMENT
Power supply
8.0 V DC / 1 A
Power supply
5.0 V DC / 1 A
J301, pin 21
pin 29
pin 30
pin 28
Modulation output level
check point
CODEC frequency
check point
Modem frequency
check point
CP101
CP216
J301, Pin 14
Entering adjustment mode
J301, pin 1
Entering transmit mode
J301
C207
C102
Modem frequency
adjustment point
CODEC frequency
adjustment point
R264
Modulation output level
adjustment point
• CODEC BOARD (TOP VIEW)
• CODEC BOARD (BOTTOM VIEW)
5 - 3