Icom IC-703 - PA Unit Adjustments

4 - 12
4-6 PA UNIT ADJUSTMENTS
IDLING
CURRENT
SWR
DETECTION
ADJUSTMENT
ADJUSTMENT ADJUSTMENT CONDITION
MEASUREMENT
VALUE
POINT
UNIT LOCATION UNIT ADJUST
1
2
3
1
2
3
• Turn R159, R164 (on the PA unit) to
maximum counterclockwise posi-
tion.
• Display frequency: 14.10000 MHz
• Mode : USB
• [MIC GAIN] : 1 (minimum)
• Transmitting
• Transmitting
• Display frequency: 14.10000 MHz
• Mode : USB
• [MIC GAIN] : 5
• Connect CP2711 on the MAIN unit
to ground.
• Connect an audio generator to
[MIC] connector and set as:
1.5 kHz/30 mV
• Transmitting
• Transmitting
PA
Rear
Panel
PA
Connect a digital
multimeter to check
point CP151.
Connect a DC
ammeter between
the DC power supply
and transceiver’s DC
power socket (W80
on the PA unit).
Connect an RF
power meter to
[ANT1] connector.
Connect a digital
multimeter to check
point CP41.
0.5 V
0.2 A increase from that
R159 is in maximum
counterclockwise posi-
tion.
0.2 A increase from
step 1.
10 W
Minimum voltage
PA
Quick
set
mode
PA
R150
R159
R164
MIC
GAIN
C561
After remove the jumper wire from CP2711 on the MAIN board.