Icom IC-775

TRANSMITTER
ADJUSTMENT
(CONTINUED)
ADJUSTMENT
ADJUSTMENT CONDITIONS
MEASUREMENT
VALUE
ADJUSTMENT
POINT
UNIT LOCATION
UNIT ADJUST
FM
CARRIER
LEVEL
1
•
Mode
:
FM
•
Transmitting
IF Connect an
oscilloscope
to CP4.
tOOmVp-pofthe
carrier viraveform
R297
FM
DEVIATION
1
•
Mode
FM
•
[MIC] control
: Center
.[MIC
TONE] : Center
.
[ANT]
:
1
•
Connect an
audio
generator to [MIC]
connector
and
set as:
Frequency :
1 kHz
Level : 30
mV
•
Transmitting
Rear
panel
Connect
an
FM
deviation
meter
to [ANT
1
]
via an
attenuator.
± 4.8
kHz
IF
R292
2 •
Set the
audio generator as:
Level : 3
mV
±
3.5 kHz
IF R281
3 Repeat
steps 1 and 2
several times.
|
RESIDUAL
AM
1
•
Mode
FM
•
[MIC]
control :
Maximum
•
[PWR]
control : Maximum
•
[ANT]
: 1
.
Connect an
audio
generator
to
[MIC]
connector and set as:
Frequency : 1
kHz
Level : 30
mV
•
Transmitting
Rear
panel
Connect an RF
pow/er
meter
to [ANTI].
Maximum
level IF
L7, L39
NOTE: After this
adjustment, adjust again R23
(see TRANSMIT TOTAL
GAIN adjustment).
AM
MODULATION
1 •
Mode
: AM
•
[ANT]
: 1
•
Connect an audio
generator to [MiC]
connector and set as:
Frequency
: 1 kHz
Level
:
30
mV
•
Transmitting
Rear
panel
Connect
a
modulation
analyzer to
[ANTI] via an
attenuator.
Maximum
modulation
Frecjjency
2
_J
95%
modulation IF R294
5-12