Tuner Section - Sony XR-C2200 Service Manual

TUNER SECTION

Cautions during repair
When the tuner unit is defective, replace it by a new one be-
cause its internal block is difficult to repair.
Note:
Adjust the tuner section in the sequence shown below.
1. FM Auto Seek/Stop Level Adjustment
2. FM Stereo Separation Adjustment
3. AM Auto Seek/Stop Level Check
FM Auto Seek/Stop Level Adjustment
Setting:
[SOURCE] button: FM
FM RF signal
generator
0.01 µF
Carrier frequency : 97.9 MHz
: 22 dB (12.6 µV)
Output level
Mode : mono
Modulation : 1 kHz, 22.5 kHz deviation (30%)
Procedure:
1. Set to the test mode. (See page 10)
2. Push the [SOURCE] button and set to FM.
3. Adjust with the volume RV2 on TU100 so that the "FM" indi-
cation 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.
Adjustment Location: See page 13.
FM Stereo Separation Adjustment
Setting:
[SOURCE] button: FM
FM RF signal
antenna jack (CN100)
generator
0.01 µF
Carrier frequency : 98.1 MHz
Output level : 70 dB (3.2 mV)
Mode : stereo
Modulation : main: 1 kHz, 33.75 kHz deviation (45%)
sub: 1 kHz, 33.75 kHz deviation (45%)
: 19 kHz pilot: 7.5 kHz deviation (10%)
12
0 dB=1 µV
antenna jack (CN100)
set
Display
SHUF
Display
SHUF
level meter
10 k Ω
set
AUDIO OUT jack (CN400)
Procedure:
FM Stereo
signal generator
output channel
L-CH
R-CH
R-CH
L-CH
L-CH Stereo separation: A-B
R-CH Stereo separation: C-D
The separations of both channels should be equal.
Specification: Separation more than 26 dB
Adjustment Location: See page 13.
AM Auto Seek/Stop Level Check
Make this adjustment after "FM Auto Seek/Stop Level Adjust-
ment".
Setting:
[SOURCE] t [MODE] button: AM
AM RF signal
generator
Carrier frequency : 1,000 kHz
30% amplitude
modulation by
1 kHz signal
Output level
Procedure:
1. Set to the test mode. (See page 10)
2. Push the [SOURCE] button and set to FM.
3. Push the [MODE] button and set to AM.
4. Check that the "AM" indication turns to "AM0" indication on
the display window.
+
–
Adjustment Location: See page 13.
Level meter
connection
L-CH
L-CH Adjust RV1 on TU100
for minimum reading.
R-CH
R-CH Adjust RV1 on TU100
for minimum reading.
30 Ω 15 pF
AM dummy antenna
(50 Ω)
antenna jack (CN100)
: 30 dB (44.7 µV)
Display
Display
Level meter
reading (dB)
A
B
C
D
65 pF
set
SHUF
SHUF