Icom IC-A24 Service Manual page 15

5-2 ADJUSTMENT
ADJUSTMENT
IDLING 1 • Operating frequency: 127.500 MHz
CURRENT
(for fi nal amp.)
[ ]
2 • Operating frequency: 118.025 MHz
3 • Operating frequency: 136.975 MHz
4 • Operating frequency: 127.500 MHz
5 • Operating frequency: 118.025 MHz
6 • Operating frequency: 136.975 MHz
move to
"TX OUTPUT POWER"
TX OUTPUT POWER 1 • Operating frequency: 127.500 MHz
[ ]
2 • Operating frequency: 118.025 MHz
3 • Operating frequency: 136.975 MHz
move to
"IDLING CURRENT"
(for driver amp.)
IDLING 1 • Operating frequency: 127.500 MHz
CURRENT
(for driver amp.)
(PRESET)
2 • Operating frequency: 118.025 MHz
[ ]
3 • Operating frequency: 136.975 MHz
4 • Operating frequency: 127.500 MHz
5 • Operating frequency: 118.025 MHz
6 • Operating frequency: 136.975 MHz
move to
"MODULATION"
MODULATION 1 • Operating frequency: 118.000 MHz
(PRESET)
[ ]
2 • Connect an 11 V power supply to the [DC 11V] jack.
MAX. 1 • Operating frequency: 127.500 MHz
MODULATION
(PRESET)
[ ]
2 • Operating frequency: 118.025 MHz
3 • Operating frequency: 136.975 MHz
ADJUSTMENT CONDITION
• Connect a DC ammeter between the battery terminal and
DC power supply (7.2 V).
• Connect DC ammeter between the [DC 11V] jack and DC
power supply (11 V).
Push [121.5] key 6 times. (Until you can fi nd [rF])
• Connect a 7.2 V DC power supply to the battery terminal.
• No audio signal apply to the microphone connector.
• Transmitting
• Transmitting
• Transmitting
Push [MR] key 9 times. (Until you can fi nd [db])
• Connect a DC ammeter between the battery terminal and
DC power supply (7.2 V).
• Connect a DC ammeter between the [DC 11V] jack and
DC power supply (11 V).
Push [121.5] key 3 times. (Until you can fi nd [d3])
• Connect a 7.2 V DC power supply to the battery terminal.
• Connect an audio generator to the [MIC] connector and set as:
1 kHz/20 mVrms
• Set a modulation analyzer as:
HPF : OFF
LPF : 20 kHz
Detector : OFF
• Transmitting
• Transmitting
• Connect a 7.2 V power supply to the battery terminal.
• Connect an audio generator to the [MIC] connector and set as:
1 kHz/20 mVrms
• Set a modulation analyzer as:
HPF : OFF
LPF : 20 kHz
Detector : (P–P)/2
• Transmitting
• Transmitting
• Transmitting
• Measure the current at "00" point ( A ).
• Rotate [DIAL] to adjust the current
A +500 mA.
• Push [ENT].
• Preset IDLING CURRENT (for driver
amp.) [
• Rotate [DIAL] to set output power to
1.5 W [USA], [GEN], [CHN]/1.0 W [EUR],
[UK], [AUS]
• Push [ENT] key.
• Measure the current at "00" point ( B ).
• Rotate [DIAL] to adjust the current
B +150 mA.
• Push [ENT] key.
• Rotate [DIAL] to set to "80".
• Push [ENT] key.
• Rotate [DIAL] to set to 30% modulation.
5 - 3
OPERATION
] to 67.
Preset to 67 before
adjusting TX output
power.