Download IC-756 Pro2 Service manual

4-4 RECEIVER ADJUSTMENTS
ADJUSTMENT
MEASUREMENT
ADJUSTMENT CONDITION
UNIT
RX PEAK
1 • Display frequency: 14.100000 MHz
• [DUAL WATCH] : OFF
• Mode
: USB
• Set following selections, controls
and functions as :
[AGC] : MID
, [ATT] : OFF
[NB] : OFF , [RIT] : OFF
PBT1 : Center , PBT2 : Center
Filter
: 2.4 kHz
[P.AMP]
: P.AMP1
[RF/SQL]
: Center
[NOTCH]
: OFF
[NR] switch
: OFF
• Preset center dots to 90˚ difference
on the roter and stater of C555 and
C655.
• Connect an SSG to [ANT1] connector and set as :
Frequency : 14.101500 MHz
Level
: 10 µV* (–87 dBm)
Modulation : 1 kHz/±5.0 kHz dev.
• Receiving
Rear
panel
VALUE
LOCATION
ADJUSTMENT
POINT
UNIT
ADJUST
RF-A
L513,
C555
RF-A
L613,
C655
distortion
RF-A
L713,
L721
Connect a spectrum Minimum noise output
analyzer to the check level
point J711.
RF-A
R515,
R516
Connect an AC milli- Maximum audio output
volt meter to [EXT level
SP] connector with
an 8 Ω load.
Adjustment L513 to upper side of 2 peak points.
2 •
•
•
•
•
Sub display freq.
[DUAL WATCH]
Mode
[BAL]
Set an SSG as
Level
: 10
• Receiving
: 14.100000 MHz
: ON
: USB
: Max. CW
:
µV* (–87 dBm)
Connect an AC milli- Maximum audio output
volt meter to [EXT level
SP] connector with
an 8 Ω load.
Adjustment L613 to upper side of 2 peak points.
3 On the MAIN-A unit, set L111, L112, L113, L141’s top to same hight with coil’s case.
FM
DISTORTION
1 • Display frequency: 14.100000 MHz
• [DUAL WATCH] : OFF
• Mode
: FM
• Filter
: 15 kHz
• [P.AMP]
: P.AMP1
• Connect an SSG to [ANT1] connector and set as :
Frequency : 14.100000 MHz
Level
: 500 µV* (–53 dBm)
Modulation : 1 kHz/±5.0 kHz Dev.
• Receiving
Rear
panel
Connect an distortion Minimum
meter to [EXT SP] level
connector with an
8 Ω load.
Adjustment in sequence L721, L713, L721.
MIXER
BALANCE
1 • Display frequency: 1.900000 MHz
• Sub display freq. : 1.900000 MHz
• [DUAL WATCH] : ON
• Mode
: USB
• [BAL]
: Max. CCW
• Apply no no RF signal to [ANT1]
connector.
• Receiving
2 • [BAL]
• Receiving
Rear
panel
: Max. CW
R615,
R616
*This output level of a standard signal generator (SSG) is indicated as SSG’s open circuit.
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