Icom IC-756PRO Service Manual

4 - 8
4-4 TRANSMITTER ADJUSTMENTS
IDLING
CURRENT
(for driver)
(for final
amplifier)
TX PEAK
TRANSMITTER
TOTAL GAIN
Ic APC
HF BANDS
OUTPUT
POWER
50 MHz BAND
OUTPUT
POWER
AM
CARRIER
ADJUSTMENT
ADJUSTMENT ADJUSTMENT CONDITION
MEASUREMENT
VALUE
POINT
UNIT LOCATION UNIT ADJUST
1
2
1
2
3
4
1
1
1
1
1
• Display frequency: 14.100000 MHz
• Mode : CW (key up)
• Preset R11, R18 on the PA unit to
max. CCW.
• [RF POWER] : Max. CW
• [TUNER] : OFF
• Transmitting (without key)
• Transmitting (without key)
• Display frequency: 14.100000 MHz
• Mode : USB
• [RF POWER] : Max. CW
• Apply no audio signals to [MIC]
connector.
• Transmitting
• Connect an audio generator to
[MIC] connector and set as:
Frequency : 1.5 kHz
Level : 1 mVrms
• Transmitting
• Transmitting
• Transmitting
• Display frequency: 14.100000 MHz
• Mode : USB
• [MIC GAIN] : Center
• Connect an audio generator to
[MIC] connector and set as:
Frequency : 1.5 kHz
Level : 1 mVrms
• Transmitting
• Display frequency: 3.550000 MHz
• Mode : RTTY
• Connect CP501 to GND.
• Transmitting
• Display frequency: 14.100000 MHz
• Mode : RTTY
• [RF POWER] : Max. CW
• [TUNER] : OFF
• Transmitting
• Display frequency: 51.000000 MHz
• Mode : RTTY
• [RF POWER] : Max. CW
• [TUNER] : OFF
• Transmitting
• Display frequency: 29.60000 MHz
• Mode : AM
• [RF POWER] : Max. CW
• [MIC GAIN] : Center
• Apply no audio signals to [MIC]
connector.
• Transmitting
PA
PA
MAIN
Rear
panel
RF
Rear
panel
Rear
panel
Rear
panel
Rear
panel
MAIN
Unsolder W29.
Connect an ammeter
to the unsoldering
points of W29.
Unsolder R28 (L8
side). Connect an
ammeter to the
unsoldering points of
R28.
Connect a digital
multimeter or oscillo-
scope to check point
CP243.
Connect an RF
power meter to
[ANT1] connector.
Connect an RF volt-
meter to check point
J151.
Connect an RF
power meter to
[ANT1] connector.
Connect an ammeter
between power sup-
ply and the IC-
756PRO.
Connect an RF
power meter to
[ANT1] connector.
Connect an RF
power meter to
[ANT1] connector.
Connect an RF
power meter to
[ANT1] connector.
100 mA
500 mA
0.13 V
50 W
Maximum output
power
Maximum leve
50 W
23 A
100 W
100 W
40 W
PA
PA
MAIN
Front
panel
MAIN
RF
MAIN
MAIN
MAIN
MAIN
MAIN
R11
R18
R247
[MIC GAIN]
control
L261
L752
R263
R545
R507
R509
R510
After adjustment, re-solder the lead wire (W29) on the PA board.
After adjustment, re-solder the resistor (R28) on the PA board.

Icom IC-756PRO Specifications

General

Brand	Icom
Model	IC-756PRO
Category	Transceiver
Language	English