Icom IC-910H Service Manual page 36

5-7 UX-910 ADJUSTMENTS
ADJUSTMENT ADJUSTMENT CONDITION
2ND LO LOCK 1 • Connect an optional UX-910 (1200
MHz band unit).
VOLTAGE
• Display frequency: 1270.5000 MHz
• Receiving
1 • Display frequency: 1240.0000 MHz
1ST LO LOCK
• Receiving
VOLTAGE
2 • Display frequency: 1300.0000 MHz
• Receiving
1 • Display frequency: 1280.0000 MHz
RECEIVER
GAIN • Connect a standard signal generator
to [12 ANT] connector and set as:
Frequency : 1280.0000 MHz
Level
Modulation : OFF
• Receiving
ATT GAIN 1 • Display frequency: 1280.0000 MHz
• [ATT]
• Set an SSG as
Frequency : 1280.0000 MHz
Level
Modulation : OFF
• Receiving
IDLING 1 • Display frequency: Any
• Mode
• Preset R61, R67, R83 to max.
clockwise, R13 to max. counter
clockwise, and C332 to center.
• Connect an RF power meter to [12
ANT].
• Connect an SSG to the check point
CP311 and set as :
Frequency : 10.8500 MHz
Level
• Transmitting
POWER 1 • Display frequency: Any
BALLANCE • Mode
• Connect an SSG to the check point
CP311 and set as :
Frequency : 10.8500 MHz
• Transmitting
2 • Display frequency: 1240.0000 MHz
• Transmitting
3 • Display frequency: 1300.0000 MHz
• Transmitting
4 Repeat step 2 and step 3 several times until power difference is minimum.
TRANSMITTER 1 • Display frequency: 1270.0000 MHz
GAIN • Set an SSG as
Frequency : 10.8500 MHz
Level
• Transmitting
*This output level of a standard signal generator (SSG) is indicated as SSG's open circuit.
UNIT
MAIN
(UX-910)
MAIN
(UX-910)
MAIN
(UX-910)
: 710 µV* (–50 dBm)
MAIN
: ON (UX-910)
:
: 710 µV* (–50 dBm)
MAIN
: CW (UX-910)
: OFF
Rear
: CW panel
Rear
: panel
: 18 mV* (–22 dBm)
From The N3UJJ.COM Document Library From The N3UJJ.COM Document Library
MEASUREMENT
LOCATION
Connect a digital
multimeter or oscillo-
scope to check point
CP701.
Connect a digital
multimeter or oscillo-
scope to check point
CP501.
Connect a spectram –34 dBm (16 dB gain)
analyzer to check
point CP311.
Connect a spectram –14 dBm (20 dB of gain
analyzer to check difference between the
point CP311. attenuator
OFF.)
Connect a digital
multimeter between
check points CP321
and CP322.
Connect an RF
power meter to [12
ANT].
Read the RF power
meter indication.
Same power as step 2
Connect an RF
power meter to [12
ANT].
5 - 18
ADJUSTMENT
POINT
VALUE
UNIT
2.6–3.8 V
6.0–7.0 V
3.4–4.4 V
MAIN
(UX-910)
MAIN
(UX-910)
ON and
0.5 V MAIN
voltage difference (UX-910)
5 W
MAIN
(UX-910)
5 W MAIN
(UX-910)
ADJUST
Verify
Verify
R224
R288
R13
Adjust
SSG's
level
Verify
C332
R83