Receiver Adjustment - Icom IC-726 Service Manual

6-3
RECEIVER
ADJUSTMENT
ADJUSTMENT
ADJUSTMENT CONDITIONS
BFO
FREQUENCY
1
• Displayed frequency: 14.10000
MHz
•
Mode
:
USB
• Receiving
2 •
Mode
:
CW
• Transmitting
•
Connect
a
key
to
the
[KEY] jack and
key down.
3 •
Mode
:
LSB
• Receiving
4 •
Mode
:
CW
•
Receiving
5 •
Mode
:
AM
• Receiving
SENSITIVITY
1
• Displayed frequency:
14.10000
MHz
•
Mode
:
USB
• [RIT]
switch
:
OFF
•[AGC]
switch
:FAST
• [ATT] switch
:
OFF
•
[NB] switch
:
OFF
•
[PRE] switch
:
ON
•
[SQL]
control
:
Max.
CCW
• Attach the
SSG
to the
[HF ANT]
connector and
set as:
Level
:
0.16
pV*(-
123
dBm)
Modulation:
OFF
• Receiving
TOTAL GAIN
1
•
Displayed frequency:
14.10000
MHz
•
Mode
:
USB
•
[RIT] switch
:
OFF
•[AGC] switch
:FAST
• [ATT] switch
:
OFF
•
[NB] switch
:
OFF
•
[PRE] switch
:
OFF
• Attach the
SSG
to the
[HF ANTj
connector
and
set as:
Level
:
1.0
mV* (-47 dBm)
Modulation:
OFF
•
Receiving
2 • Attach the
SSG
to
the
[HF ANTj
connector and
set as:
Level
:
OFF
S-METER
1
• Displayed frequency: 14.10000
MHz
•
Mode
:
USB
•
[PRE] switch
:
OFF
• Attach the
SSG
to the
[HF ANT]
connector
and
set as:
Level
:
50
nV*(-73dBm)
Modulation:
OFF
• Receiving
2 •
Attact the
SSG
to
the
[HF ANT]
connector
and
set
as
:
Level
:
50
mV* (-13 dBm)
3 Repeat
step
1
and
2 several times.
UNIT
MAIN
Rear
panel
Rear
panel
Front
panel
MEASUREMENT
LOCATION
Connect
the
frequency counter
to
R266.
Connect
the
AC
milli-
voltmeter
to
the
[EXT
SP] jack
with
an
8
O
load.
Connect
the
AC
milli-
voltmeter
to
the
[EXT
SP] jack with an 8
D
load.
S-METER
VALUE
ADJUSTMENT
POINT
UNIT
ADJUST
9.01300
MHz MAIN C294
9.01060
MHz
L83
9.01000
MHz
L82
9.00980
MHz
<±150
Hz)
Verify
No
output
Preset
to
max.
CW.
MAIN R138
Maximum
audio output
level
Adjust
in
sequence
]
L33, L34,
L35, L36,
L21, L22,
L23, L79,
L78,
L77
1.0
V
(0
dB)
Front
panel
[AF]
control
30
mV
(-30
dB)
MAIN R138
S9
MAIN R116
S9+60 dB
R110
*This
output
level
of the
standard
signal
generator (SSG)
is
indicated as
SSG's open
circuit.
6
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4