Receiver Adjustment - Icom IC-756PROII Service Manual

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