Pa Unit Adjustment - Icom IC-7600 Service Manual

4-4 PA UNIT ADJUSTMENT

ADJUSTMENT ADJUSTMENT CONDITION
IDLING "IDLING" must be adjusted by cold-started.
(Preparation)
1
IDLING 2 • Frequency
(PRE- • Mode
DRIVER) • Push [TRANSMIT] to transmit.
IDLING 3 • Frequency
(DRIVER) • Mode
• Push [TRANSMIT] to transmit.
4
IDLING 5 • Frequency
(FINAL AMP) • Mode
• Push [TRANSMIT] to transmit.
6
7 Apply slight vibration to the PA UNIT, and verify that the current is stable against the vibration.
1) Set 5 variable resisters to the preset
point.
2) Disconnect the power cable from
–
the transceiver, and connect an DC
Ammeter (30 A) between the power
supply and transceiver.
: 14.100 MHz 1) Connect a Digital multimeter to CP1
: CW and adjust the voltage.
2) Measure the current, and note it as
the initial value.
: 14.100 MHz • Adjust the current.
: CW
• Adjust the current.
: 14.100 MHz • Adjust the current.
: CW
• Adjust the current.
4 - 6
OPERATION
ADJUSTMENT
VALUE
POINT
R4,
R14, Max.
R16, counter
R65, clockwise
R67
0.5 V
R4
(0.4–0.6 V)
+1.0 A
R14 more than
"Step 2"
+1.0 A
R16 more than
"Step 3"
+1.0 A
R65 more than
"Step 4"
+1.0 A
R67 more than
"Step 5"