RX-V990
FM
Adjustment
•
Before Adjustment
1) For dB, 1µV=OdBµ applies.
Example:
60dBµ=1mV
2) 100% modulation means that the frequency deviation is
75kHz.
3) Install the Matching Transformer and connect FM SG.
•
Connection diagram (Measuring instruments)
1) Discriminator
balance adjustment
FM
ANT
I
TUNER
GND
P.
C. B.
DCVM
FM
dummy
antenna
FM
SG
TP2
2) Monaural distortion adjustment
FM
ANT
L
TUNER
P. C. B.
FM
dummy
antenna
R
:
...0.-
REC
I
lOUT
FM
SG
GND
See page 10 for TP locations
&
adjustment
points.
4) Set each switch to the following position unless other-
wise specified.
INPUT SELECTOR
TUNER
TUNING MODE
AUTO
3) Stereo distortion adjustment/separation adjustment
,
,
FM
FM
H
dummy
SG
antenna
4) Sensitivity Verification
FM
ANT
GND
L
TUNER
P. C. B.
R
:
FM
dummy
antenna
FM
SG
REC
I
lOUT
Step
Adjustment
item
Reception
Adjustment
Test point
Rating
Signal (ANT IN)
frequency
point
1
Rough adjustment
of
FM ANT (750)
98.1MHz
T1
Both ends of R25
DC OV±100mV
discriminator
balance
98.1MHz
• (A-4)
(Front side core)
(Between TP1 and TP2)
70dBµ
MONO 1kHz
100% modulation
2
Rough adjustment
of
Same as Step 1.
98.1MHz
T1
REC OUT L, R
Minimize the dis-
monaural distortion
• (A-4)
(Antenna side core)
tortion.
3
Fine
adjustment
of
Same as Step 1.
98.1MHz
T1
Both ends of R25
DC OV±50mV
discriminator
balance
• (A-4)
(Front side core)
(Between TP1 and TP2)
4
Fine
adjustment
of
Same as Step 1.
98.1MHz
T1
REC OUT L, R
Minimize the dis-
monaural distortion
• (A-4)
(Antenna side core)
tortion (to 0.25%
or less).
5
Verification
of dis-
Same as Step 1.
98.1MHz
T1
Both ends of R25
DC OV±50mV
criminator balance
• (A-4)
(Front side core)
(Between TP1 and TP2)
• : Execution of FACTORY
PRESET (Refer to page 7.) will facilitate setting reception frequency for adjustment.
11
Summary of Contents for RX-V990
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