Tuner Section - Sony XR-4750RDS Service Manual
Fm/mw/lw cassette car stereo
Hide thumbs
Also See for XR-4750RDS:
- Operating instructions manual (76 pages) ,
- Service manual (48 pages) ,
- Installation/connections (4 pages)
Table of Contents
Advertisement
QQ
3 7 63 1515 0
TUNER SECTION
0dB=1µV
Cautions during repair
When the tuner unit is defective, replace it by a new one because
its internal block is difficult to repair.
[Note]
Adjust the tuner section in the sequence shown below.
1. FM Auto Scan/Stop Level Adjustment
2. FM Stereo Separation Adjustment
3. FM Noise Focus Adjustment
4. FM Signal Meter Adjustment
5. AM (MW) Auto Scan/Stop Level Adjustment
FM Auto Scan/Stop Level Adjustment
Setting:
SOURCE button: FM
FM RF signal
generator
0.01 µ F
Carrier frequency
: 98.0 MHz
: 22 dB (12.6 µ V)
Output level
Mode
: mono
Modulation
: 1 kHz, 22.5 kHz deviation (30%)
Procedure:
TE
1. Set to the test mode. (See page 15).
L 13942296513
2. Push the SOURCE button and set to FM.
Display
REG
FM
3. Push the preset 3 button.
Display
REG
FM
4. Adjust with the volume RV2 on TU1 so that the "FM" indica-
tion turns to "FM0" indication on the display window.
But, in case of already indicated "FM0", turn the RV2 so that
put out light "0" indication and adjustment.
Display
REG
www
Adjustment Location: See page 18.
.
http://www.xiaoyu163.com
antenna jack (J1)
set
INTRO
INTRO
INTRO
x
ao
y
i
http://www.xiaoyu163.com
8
FM Stereo Separation Adjustment
Setting:
SOURCE button: FM
FM RF signal
antenna jack (J1)
generator
0.01 µ F
Carrier frequency : 98.0 MHz
Output level
: 70 dB (3.2 mV)
Mode
: stereo
Modulation
: main: 1 kHz, 20 kHz deviation (26.7%)
sub: 1 kHz, 20 kHz deviation (26.7%)
:
19 kHz pilot: 7.5 kHz deviation (10%)
Procedure:
FM Stereo
signal generator
output channel
L-CH
R-CH
R-CH
L-CH
Q Q
3
6 7
1 3
L-CH Stereo separation: A-B
R-CH Stereo separation: C-D
The separations of both channels should be equal.
Specification: Separation more than 30 dB
Adjustment Location: See page 18.
FM Noise Focus Adjustment
Setting:
SOURCE button: FM
FM RF signal
antenna jack (J1)
generator
0.01 µ F
Carrier frequency : 98.00 MHz
Output level
: 60 dB (1 mV)
Mode
: stereo
Modulation
: 1 kHz, 75 kHz deviation (100%)
Procedure:
1. Tuner the 98.00 MHz.
2. The then output level is supposing that (A) dB.
u163
3. Adjust with the volume RV3 on TU1 so that the output level is
(A) –32 ± 2 dB then signal generator input set to –20 dB.
.
Adjustment Location: See page 18.
– 16 –
2 9
9 4
2 8
level meter
4 Ω
set
speaker out terminal
Level meter
Level meter
connection
reading (dB)
A
L-CH
B
L-CH
Adjust RV4 on TU1
for minimum reading.
C
R-CH
D
R-CH
Adjust RV4 on TU1
for minimum reading.
1 5
0 5
8
2 9
9 4
level meter
4 Ω
set
speaker out terminal
m
co
9 9
+
–
2 8
9 9
+
–
Hide quick links:
Advertisement
Table of Contents
