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Receiver adjustments, 4 receiver adjustments – Icom IC-910H User Manual

Page 22

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*This output level of a standard signal generator (SSG) is indicated as SSG’s open circuit.

5 - 4

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.

144 M
RECEIVER
PEAK/GAIN

144 M PEAK
(MAIN BAND)

144 M
TOTAL GAIN
(MAIN BAND)

144 M PEAK
(SUB BAND)

144 M
TOTAL GAIN
(SUB BAND)

ADJUSTMENT

ADJUSTMENT

ADJUSTMENT CONDITION

MEASUREMENT

VALUE

POINT

UNIT

LOCATION

UNIT

ADJUST

1

2

1

2

1

2

1

2

1

2

• Display frequency: Any
• Disconnect P501 (PA unit) from J51

on the MAIN unit.

• Connect a standard signal generator

to [VHF ANT] connector and set as:

Frequency : 146.0000 MHz
Level

: 7.1 mV* (–30 dBm)

Modulation : OFF

• Receiving

• Receiving

• Display frequency: 145.9800 MHz
• Mode

: FM

• Connect an SSG to [VHF ANT] con-

nector and set as:

Frequency : 145.9800 MHz
Level

: 3.2 µV* (–97 dBm)

Modulation : 1 kHz/±5.0 kHz Dev.

• Receiving

• Mode

: USB

• Set an SSG as

:

Frequency : 145.9815 MHz
Level

: 0.1 µV* (–127 dBm)

Modulation : OFF

• Receiving

• Display frequency: 145.9800 MHz
• Mode

: USB

• Set an SSG as

:

Frequency : 145.9815 MHz
Level

: 1 mV* (–47 dBm)

Modulation : OFF

• Receiving

• Set an SSG as

:

Level

: OFF

• Receiving

• Sub display freq. : 145.9800 MHz
• Mode

: FM

• Connect an SSG to [VHF ANT] con-

nector and set as:

Frequency : 145.9800 MHz
Level

: 3.2 µV* (–97 dBm)

Modulation : 1 kHz/±5.0 kHz Dev.

• Receiving

• Mode

: USB

• Set an SSG as

:

Frequency : 145.9815 MHz
Level

: 0.1 µV* (–127 dBm)

Modulation : OFF

• Receiving

• Display frequency: 145.9800 MHz
• Mode

: USB

• Set an SSG as

:

Frequency : 145.9815 MHz
Level

: 1 mV* (–47 dBm)

Modulation : OFF

• Receiving

• Set an SSG as

:

Level

: OFF

• Receiving

PA

Rear

panel

Rear

panel

Rear

panel

Rear

panel

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.

Maximum level

–14 dBm

Minimum audio distor-
tion level

Maximum noise output
level

1.0 V (0 dB)

100 mV (20 dB of AF
level difference as step
1.)

Minimum audio distor-
tion level

Maximum noise output
level

1.0 V (0 dB)

100 mV (20 dB of AF
level difference as step
1.)

PA

MAIN

Front

panel

MAIN

MAIN

Front

panel

MAIN

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

After adjustment, connect P501 (PA unit) to J51 on the MAIN unit.