Receiver Adjustment - Icom ic-775 Service Manual

5-3
RECEIVER
ADJUSTMENT
ADJUSTMENT
ADJUSTMENT
CONDITIONS
MEASUREMENT
VALUE
ADJUSTMENT
POINT
UNIT
LOCATION
UNIT
ADJUST
AGC
VOLTAGE
1
• Displayed freque
•
Mode
.
[PREAMP/ATT]
.
[METER]
.
[ANT]
.
[TUNER]
•
[AGC]
.
[DRIVE]
•
[NB]
.
[COMP]
•
[RF]
.
[TONE]
•
[SQL]
.
[MIC]
.
[PWR]
.
[MONI GAIN]
•
[MIC
TONE]
•
[ANTI-VOX]
•
[VOX-GAIN]
•
[VOX]
•
[MONITOR]
.
[DUALWATCH]
•
[SPLIT]
•
[TWIN PBT]
•
[APF]
•
[NOTCH]
•
[RIT]
•
[ATX]
.
S2
(IF unit)
• Receiving
ncy:
14.100000
MHz
USB
PRE
1
Po
1
OFF
Max. counterclockwise
Max.
clockwise
OFF
OFF
Max. clockwise
Center
Max.
counterclockwise
Center
Max.
clockwise
Center
Center
Center
Center
OFF
OFF
OFF
OFF
Center
OFF
OFF
OFF
OFF
ON
IF
Connect a
digital
multi-
meter
or oscilloscope
to
CPI.
2.40
V
IF
R439
RX PEAK
1
•
Displayed freque
•
Mode
•
[PREAMP/ATT]
.
[AGC
OFF]
.
[ANT]
•
R24
(RF
unit)
•
R50 (RF
unit)
•
Connect a
standt
[ANTI]
and
set
a
Frequency
:
Level
Modulation:
Deviation
:
ncy: 14.100000
MHz
FM
OFF
OFF
(AGC
activates)
1
Center
Center
ird signal
generator
to
s:
4.100000
MHz
0
pV
*
(-87
dBm)
-M
1
kHz
b7.5
kHz
Front
panel
S/RF
meter
Maximum
level
RF
Adjust
repeatedly
L41,L51,
L56, L55,
L54
2
•
[AGC
OFF]
ON
(AGC
deactivates)
•
Set
the standard signal generator
as:
Level
:
3.2
pV
*
(-97
dBm)
Rear
panel
Connect a
distortion
meter
to
[EXT SP]
jack.
Minimum
distortion level
L51, L56,
L55,
L54
3
• Displayed frequency
:
1
00 kHz
.
[AGC OFF]
:
OFF
(AGC
activates)
•
Mode
:
USB
•
Apply no
signal to
the
antenna
connector.
Connect an
AC
millivolt-
meter
to
[EXT SP]
jack
with
an 8
Q dummy
load.
Minimum
noise
level
R50
RECEIVER
TOTAL GAIN
1
•
Same
settings
as
"AGC VOLTAGE"
•
Connect a standard
signal
generator
to
[ANT1] and
set as:
Frequency: 14.101500
MHz
Level
:
0.5
pV
*
(-11 3
dBm)
Modulation:
OFF
Rear
panel
Connect an
AC
millivolt-
meter
to
[EXT
SP]
jack
with
an 8
O
dummy
load.
Maximum
audio
output level
IF
Adjust
in
sequence
L3, L4,
L5, L6,
L12, L14,
LI
5,
LI
9,
L36, L20,
L21
2
.
[PREAMP/ATT]
:
OFF
•
Set the standard
signal generator
as:
Level
:
0.5
mV
*
(-53
dBm)
and
OFF
30
dB
(32
mV)
of
AF
level
difference
IF
R198
*
This output
level of
the standard
signal
generator
(SSG)
is
indicated
as SSG's open
circuit.
5-4