Transmitter Adjustment - Icom IC-91A Service Manual

6-2 TRANSMITTER ADJUSTMENT

• Set the specified value using [DIAL], and push [BAND] to store the set value. Then push [2] to move to the next adjustment item.
NOTE: "REFERENCE FREQUENCY" should be adjusted before "FM DEVIATION" and "RXBPF." Otherwise, these adjustments
will not be adjusted properly.
ADJUSTMENT ITEM
REFERENCE
FREQUENCY
(4
[Fr]
TX POWER
IDLING 5.0 V
(VHF)
KF
[id]
(UHF)
FINAL 5.0V
(VHF)
2Q
[Po]
(UHF)
TX POWER
IDLING 7.4V
+F
[Id]
(VHF)
(UHF)
NOTE: Take notes of this adjustment value.
FINAL 7.4V
2Q
[Po]
(VHF)
(UHF)
TX POWER
IDLING 13.5V
+F
[Id]
(VHF)
(UHF)
FINAL 13.5V
2Q
[Po]
(VHF)
(UHF)
(1); Adjustment value for the case If the output power exceeds 4.0 W.
(2); Set to the value in which 3 is subtracted from the [Id] value set by "TX POWER IDLING 7.4 V (UHF)/[LOW]."
ADJUSTMENT CONDITION
1 • Connect an RF power meter to the antenna connector.
• Loosely couple a frequency counter to the antenna connector.
• Transmitting
1 • Power supply voltage : 5.0 V
• Adjustment value of 2Q : 00
• Connect an RF power meter to the antenna connector.
• Transmitting
2 • Transmitting
1 • Transmitting
2 • Transmitting
1 • Power supply voltage : 7.4 V
• Adjustment value of 2Q : 00
• Transmitting
2 • Transmitting
(This value is used as reference for "TX POWER IDLING 13.5V" adjustment)
1 • Transmitting
2 • Transmitting
1 • Power supply voltage : 13.5 V
• Adjustment value of 2Q : 00
• Transmitting
2 • Transmitting
1 • Transmitting
2 • Transmitting
6 - 3
VALUE
440.000 MHz
10 mW
0.1 W
[HIGH]: 5.0 W
[LOW]: 40–100 mW
[HIGH]: 5 W
[LOW]: 0.5 W
[HIGH]:
• Adjustment value: 58
or
(1)
• TX pwr.: 3.0–4.0 W
[LOW]: 40–100 mW
[HIGH]
• Adjustment value: 58
or
• TX power: 3.0–4.0 W
[LOW]:
Adjustment value: (2)
[HIGH]: 4.6–5.2 W
[LOW]: 0.4–0.6 W