![background image](http://html.mh-extra.com/html/icom/ic-m220/ic-m220_service-manual_612744011.webp)
4-3
ADJUSTMENT
TRANSCEIVER’S
CONDITION
OPERATION
ADJUSTMENT
ITEM
VALUE
REFERENCE
FREQUENCY
-Verification-
1 • Operating channel: 16
• Transmitting
• Connect the RF power meter
(or dummy load) to the antenna
connector.
• Loosely coupled the frequency
counter to the antenna connector.
• No audio signal is applied to the
FRONT MIC JACK.
–
156.800 MHz
(±500 Hz)
4-3 RECEIVE ADJUSTMENTS
1)
Select an adjustment item by pushing [↑]/[↓] on the PC keyboard.
2)
Set or modify the adjustment value as specified by pushing [←]/[→], and then push [Enter] to store the value.
ADJUSTMENT
TRANSCEIVER’S
CONDITION
OPERATION
ADJUSTMENT
ITEM
VALUE
RECEIVE
SENSITIVITY
-Verification-
1 • Operating channel: 16
• Receiving
•
Connect an standard signal generator
(SSG) to the antenna connector and
set it to:
Frequency: 156.800 MHz
Modulation: 1 kHz
Deviation: ±3.0 kHz
Level:
–10 dBμ (–117 dBm)
• Connect the distortion meter to SP+
(blue) and SP− (black) lines of the AF
out leads.
–
12 dB SINAD
or better
(Band low)
2 • Operating channel: 01
• Receiving
• Set
the SSG to:
Frequency: 156.050 MHz
(Band high)
3 • Operating channel: 88
• Receiving
• Set
the SSG to:
Frequency: 157.425 MHz
SQUELCH
-Adjustment-
(Threshold)
1 • Operating channel: 16
• Receiving
• Set
the SSG to:
Level:
–13.5 dBµ (–120.5 dBm)
[RSSI
(Threshold)]
Push [Enter]
(Automatic
adjustment)
(Tight)
2
•
Set the SSG to:
Level:
–3.5 dBµ (–110.5 dBm)
[RSSI (Tight)]
-Verification-
3 • Operating channel: 16
• SQL:
10
• Receiving
•
Set the SSG to:
Level: 0
dBµ (–107 dBm)
–
Squelch
open
AUDIO OUTPUT
-Verification-
(Distortion)
1 • Operating channel: 16
• Audio output level: 19
• Receiving
•
Set the SSG to:
Level: 60
dBµ (–47 dBm)
–
7 ~ 13%
distortion
(Output level)
2
More than
3.5 W (3.74 V)
RX SIGNAL-TO-
NOISE RATIO
-Verification-
1 • Operating channel: 16
• Receiving
•
Set the SSG to:
Level: 40
dBµ (–67 dBm)
•
Adjust the AF output to 50% of rated.
•
Verify the AF output level difference
when a modulated and an
unmodulated signal is received.
–
More than
40 dB
RX POWER
CONSUMPTION
-Verification-
1 • Operating channel: 16
• Maximum AF volume
• Maximum LCD brightness
• Receiving
•
Set the SSG to:
Level: 60
dBµ (–47 dBm)
•
Connect the ammeter between the
DC power connector and the DC
power supply.
–
Less than
1.2 A
WX Alert
-Verification-
1 • Operating
channel: WX10
• Receiving
•
Set the SSG to:
Frequency: 163.275 MHz
Modulation: 1.05 kHz
Deviation: ±3.0 kHz
Level: 0
dBµ (–107 dBm)
–
WX Alert
sounds
4-2 FREQUENCY ADJUSTMENTS
1) Select an adjustment item using [↑]/[↓]/[←]/[→] on the PC’s keyboard.
2) Set or modify the adjustment value as specified using [Space]/[Back Space] on the PC’s keyboard.