Icom IC-756PRO Service Manual page 22

RECEIVER ADJUSTMENTS—continued
ADJUSTMENT ADJUSTMENT CONDITION
RECEIVER 1 • Display frequency: 14.100000 MHz
TOTAL GAIN • Mode
• Filter
• [P.AMP]
• Connect an SSG to [ANT1] connec-
tor and set as
Frequency : 14.101500 MHz
Level
Modulation : OFF
• Receiving
2 • Set an SSG output level to OFF.
• Receiving
NOISE 1 • Display frequency: 14.100000 MHz
• Mode
BLANKER
• [P.AMP]
• [NB]
• Connect an SSG to [ANT1] con-
nector and set as :
Frequency : 14.101500 MHz
Level
Modulation : OFF
and apply following signal to [ANT1]
connector.
100 msec.
• Preset R271 on the MAIN unit to
the 12 o'clock position.
• Receiving
2 • [NB]
• Receiving
SPECTRUM 1 • Display frequency: 14.100000 MHz
SCOPE • Mode
• [DUAL WATCH] : OFF
• [P.AMP]
• [SCOPE]
• [SCOPE ATT]
• Verify the connection of J841 on the
RF unit and P801 (S3LO: 12.89000
MHz/–7 dBm) from the PLL unit.
• Connect an SSG to [ANT1] con-
nector and set as :
Frequency : 14.101500 MHz
Level
Modulation : OFF
• Receiving
2 • Set an SSG output level to OFF.
• Receiving
3 • Set an SSG output level as:
Level
• Receiving
*This output level of a standard signal generator (SSG) is indicated as SSG's open circuit.
UNIT
Rear
: USB panel
: 2.4 kHz
: OFF
:
: 500 µV* (–53 dBm)
MAIN
: USB
: P.AMP1
: OFF
: 10 µV* (–87 dBm)
1 msec.
: ON
RF
: USB
: OFF
: ON
: OFF
: 1 µV* (–107 dBm)
: 50 mV* (–13 dBm)
MEASUREMENT
LOCATION
Connect an AC milli-
volt meter to [EXT
SP] connector with
an 8 Ω load.
Connect an oscillo- Maximum noise level
scope to check point
CP271.
At the point where the
voltage just reduces.
Connect a digital
multimeter oroscillo-
scope to check point
CP871.
4 - 6
ADJUSTMENT
POINT
VALUE
UNIT
1.0 V (0 dB) Front
unit
32 mV (–30 dB) MAIN
MAIN
Muximum voltage RF
0.05 V–0.15 V
4.35 V– 4.45 V
ADJUST
[AF]
control
R210
L271,
L272
R271
L812,
L813,
L833
R872
R863