Osc Unit Adjustments - Icom IC-7800 Service Manual

4-2 OSC UNIT ADJUSTMENTS

ADJUSTMENT ADJUSTMENT CONDITION
REFERENCE
1 • Set the OSC unit to the external
OUTPUT
reference mode on the set mode.
• MAIN display frequency
• Connect an SSG to J71 on the
OSC unit and set as;
Frequency
Level
Modulation
• Terminates J73 with 50
• Receiving
REF IN
2 • Receiving
OUTPUT
• Terminates J72 with 50
• Receiving
REF OUT
3 • Set the OSC unit to the internal
OUTPUT
reference mode on the set mode.
• Receiving
• Terminates J73 with 50
• Receiving
• Terminates J72 with 50
• Receiving
*This output level of a standard signal generator (SSG) is indicated as SSG's open circuit.
MEASUREMENT
UNIT
OSC
: 10.000 MHz
: 10.000 MHz
: 71 mV* (–10 dBm)
: OFF
Ω
.
OSC
Ω
.
OSC
Ω
.
Ω
.
4 - 2
LOCATION
C o n n e c t a n R F Maximum voltage
voltmeter to J72.
C o n n e c t a n R F 0 dBm ±3.0 dB
voltmeter to J72.
C o n n e c t a n R F 0 dBm ±3.0 dB
voltmeter to J73.
C o n n e c t a n R F –10.0 dBm ±3.0 dB
voltmeter to J71.
C o n n e c t a n R F 0 dBm ±3.0 dB
voltmeter to J72.
C o n n e c t a n R F 0 dBm ±3.0 dB
voltmeter to J73.
ADJUSTMENT
POINT
VALUE
UNIT ADJUST
OSC
repeatedly
Adjust
L61,
L62
Verify
Verify
Verify
Verify
Verify