Receiver Adjustments - Icom IC-703 Service Manual

4-4 RECEIVER ADJUSTMENTS

ADJUSTMENT ADJUSTMENT CONDITION
RECEIVER 1 • Display freq.
PEAK • Mode
• [RIT]
• [AGC]
• [NB]
• [P.AMP/ATT]
• Connect a standard signal genera-
tor to the [ANT] connector and set
as:
Frequency
Level
Modulation : OFF
• Receiving
1 • [P.AMP/ATT]
RECEIVER
TOTAL GAIN • Set an SSG as:
Frequency
Level
Modulation : OFF
• Receiving
NOISE 1 • Display freq.
BLANKER • Mode
• [P.AMP/ATT]
• [NB]
• Connect an SSG to the [ANT] con-
nector and set as:
Frequency
Level
Modulation : OFF
and apply the following signal to
the [ANT] connector.
1 msec.
• Receiving
2 • [NB]
• Set an SSG as:
Level
Modulation : OFF
• Receiving
*This output level of the standard signal generator (SSG) is indicated as SSG's open circuit.
: 14.15000 MHz
: USB
: OFF
: Fast (F AGC)
: OFF
: Preamp ON
: 14.15150 MHz
: 0.5 µV* (–113 dBm)
: Preamp OFF
: 14.15150 MHz
: 500 µV* (–53 dBm)
and OFF
: 14.15000 MHz
: USB
: Preamp ON
: ON
: 14.15150 MHz
: 18 µV* (–82 dBm)
100 msec.
: ON
: 10 µV* (–87 dBm)
MEASUREMENT
UNIT LOCATION
Rear Connect an AC milli-
Panel voltmeter to the [EXT
SP] jack with an 8 Ω
dummy load.
Rear Connect an AC milli-
Panel voltmeter to the [EXT
SP] jack with a 8 Ω
dummy load.
MAIN Connect an oscillo-
scope to check point
CP1001.
4 - 8
ADJUSTMENT
VALUE
UNIT
Maximum AF output MAIN
level
30 dB of AF level differ- MAIN
ence
Adjust the maximum MAIN
noise wave displayed
on the oscilloscope.
At the point where the
noise just reduces.
POINT
ADJUST
L881,
L882,
L1101,
L1102,
L1201
R1203
L1052,
L1053
Verify