Receiver Adjustments - Icom IC-910H Service Manual

5-4 RECEIVER ADJUSTMENTS

Receiver adjustments must be performed after software adjustment (0) and (1). SUB band must be OFF when adjusting MAIN band,
or main AF volume (max.counter clockwise) and SQL volume (max. clockwise) must be set when adjusting SUB band.
ADJUSTMENT ADJUSTMENT CONDITION
144 M 1 • Display frequency: Any
RECEIVER • Disconnect P501 (PA unit) from J51
PEAK/GAIN on the MAIN unit.
• Connect a standard signal generator
to [VHF ANT] connector and set as:
Frequency : 146.0000 MHz
Level
Modulation : OFF
• Receiving
2 • Receiving
After adjustment, connect P501 (PA unit) to J51 on the MAIN unit.
144 M PEAK 1 • Display frequency: 145.9800 MHz
(MAIN BAND) • Mode
• Connect an SSG to [VHF ANT] con-
nector and set as:
Frequency : 145.9800 MHz
Level
Modulation : 1 kHz/±5.0 kHz Dev.
• Receiving
2 • Mode
• Set an SSG as
Frequency : 145.9815 MHz
Level
Modulation : OFF
• Receiving
1 • Display frequency: 145.9800 MHz
144 M
• Mode
TOTAL GAIN
• Set an SSG as
(MAIN BAND)
Frequency : 145.9815 MHz
Level
Modulation : OFF
• Receiving
2 • Set an SSG as
Level
• Receiving
144 M PEAK 1 • Sub display freq. : 145.9800 MHz
(SUB BAND) • Mode
• Connect an SSG to [VHF ANT] con-
nector and set as:
Frequency : 145.9800 MHz
Level
Modulation : 1 kHz/±5.0 kHz Dev.
• Receiving
2 • Mode
• Set an SSG as
Frequency : 145.9815 MHz
Level
Modulation : OFF
• Receiving
144 M 1 • Display frequency: 145.9800 MHz
TOTAL GAIN • Mode
(SUB BAND) • Set an SSG as
Frequency : 145.9815 MHz
Level
Modulation : OFF
• Receiving
2 • Set an SSG as
Level
• Receiving
*This output level of a standard signal generator (SSG) is indicated as SSG's open circuit.
UNIT
: 7.1 mV* (–30 dBm)
Rear
: FM panel
: 3.2 µV* (–97 dBm)
: USB
:
: 0.1 µV* (–127 dBm)
Rear
: USB panel
:
: 1 mV* (–47 dBm)
:
: OFF
Rear
: FM panel
: 3.2 µV* (–97 dBm)
: USB
:
: 0.1 µV* (–127 dBm)
Rear
: USB panel
:
: 1 mV* (–47 dBm)
:
: OFF
From The N3UJJ.COM Document Library From The N3UJJ.COM Document Library
MEASUREMENT
LOCATION
PA Connect an RF volt-
meter to check point
P501 via the JIG
cable (A).
Connect an distortion
meter to [EXT SP]
connector with an
8 Ω load.
Connect an AC milli-
volt meter to [EXT
SP] connector with
an 8 Ω load.
Connect an AC milli-
volt meter to [EXT
SP] connector with
an 8 Ω load.
Connect an distortion
meter to [EXT SP]
connector with an
8 Ω load.
Connect an AC milli-
volt meter to [EXT
SP] connector with
an 8 Ω load.
Connect an AC milli-
volt meter to [EXT
SP] connector with
an 8 Ω load.
5 - 4
ADJUSTMENT
VALUE
UNIT
Maximum level PA
–14 dBm
Minimum audio distor- MAIN
tion level
Maximum noise output
level
1.0 V (0 dB) Front
panel
100 mV (20 dB of AF MAIN
level difference as step
1.)
Minimum audio distor- MAIN
tion level
Maximum noise output
level
1.0 V (0 dB) Front
panel
100 mV (20 dB of AF MAIN
level difference as step
1.)
POINT
ADJUST
L521
R547
Adjust in
sequence
L51, L52
s e v e r a l
times.
L53, L352,
L353, L354
main [AF]
volume
R360
Adjust in
sequence
L651, L652
s e v e r a l
times.
L653, L851,
L852, L853
sub [AF]
volume
R857