Icom IC-756PROIII Service Manual page 30

RECEIVER ADJUSTMENTS—continued
ADJUSTMENT ADJUSTMENT CONDITION
RECEIVER
1 • Display freq.
TOTAL GAIN
• [DUALWATCH]
• Mode
• Filter
• [AGC]
• [P.AMP]
• Connect an SSG to [ANT1] con-
nector and set as:
Frequency : 14.101500 MHz
Level
Modulation : OFF
• Receiving
NOISE
1 • Display freq.
BLANKER
• [DUALWATCH]
• Mode
• [AGC]
• [P.AMP]
• [NB]
• [NB LEVEL]
• 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-A unit to
the center position.
• Receiving
2 • [NB]
• Receiving
SPECTRUM
1 • Display freq.
SCOPE
• Mode
• [DUALWATCH]
• [P.AMP]
• [SCOPE]
• [SCOPE ATT]
• Verify the connection of J2001 on
the RF-B 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
: 14.100000 MHz MAIN-A
: OFF
: USB
: 2.4 kHz
: OFF
: OFF
: 160 mV* (–3 dBm)
: 14.100000 MHz MAIN-A
: OFF
: USB
: MID
: P.AMP1
: OFF
: 50%
: 5.6 µV* (–92 dBm)
1 msec.
: ON
: 14.100000 MHz RF-B
: USB
: OFF
: OFF
: ON
: OFF
: 1 µV* (–107 dBm)
: 50 mV* (–13 dBm)
MEASUREMENT
LOCATION
Connect an oscil-
loscope to the check
point CP213.
Connect an oscil- Maximum noise level
loscope to the check
point CP271.
At the point where the
voltage just reduces.
Connect a digital
multimeter or oscil-
loscope to the check
point CP2002.
4 - 10
ADJUSTMENT
POINT
VALUE
UNIT
3.7 Vp-p MAIN-A
MAIN-A
Maximum voltage RF-B
0.1 V
4.4 V
ADJUST
R210
L271,
L272,
L273
R271
L2102,
L2201,
L2202
R2012
R2016