Sony XR-2750 Service Manual page 19

FM Stereo Separation Adjustment
Setting:
SOURCE button: FM
FM RF signal
generator
antenna jack (J1)
Carrier frequency : 98.0 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%)
Procedure:
FM Stereo
Level meter
signal generator
connection
output channel
L-CH L-CH
R-CH L-CH
R-CH R-CH
L-CH R-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 20.
level meter
4 Ω
+
set
–
SPEAKER OUT
Level meter
reading (dB)
A
B
Adjust RV4 on TU1
for minimum reading.
C
D
Adjust RV4 on TU1
for minimum reading.
– 19 –
MW Auto Scan/Stop Level Adjustment
Setting:
SOURCE and MODE button: MW
AM RF signal
generator
AM dummy antenna
(50 Ω )
Carrier frequency : 999 kHz
30% amplitude
modukation by
1 kHz signal
Output level : 33 dB (44.7 µV)
Procedure:
1. Set to the test mode. (See page 17.)
2. Push the SOURCE button and set to FM.
3. Push the MODE button and set to MW.
Display
MW
INTRO
SHUF1
4. Push the preset 3 button.
Display
MW
INTRO
SHUF1
5. Adjust with the volume RV1 on TU1 so that the "MW" indi-
cation turns to "MWI" indication on the display window.
But, in case of already indicated "MWI", turn the RV1 so that
put out light "I" indication and adjustment.
Display
INTRO
SHUF1
Adjustment Location: See page 20.
30 Ω 15 pF
65 pF
set
antenna jack
999
999
3
999
3