Sony RXD-700, Руководство по обслуживанию

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TAPE
REC OUT
FM ANTENNA
75
Ω COAXIAL
TAPE
REC OUT
FM ANTENNA
75
Ω
COAXIAL
FM SECTION
Cautions during repair
When the front end is defective, replace it by a new one because
its internal block is difficult to repair.
SECTION 3
DISASSEMBLY
FM Stereo Separation Adjustment
Setting :
TUNER button : FM
set
0 dB = 1
µ
V
FM Discriminator Adjustment
(NULL and MONO Distortion Adjustment)
Setting :
TUNER button : FM
Procedure :
1. Tune the set to 98.0 MHz.
2. Adjust L702 for 0
±
25 mV reading on the digital voltmeter.
............ NULL
3. Adjust L703 for a minimum reading on the distortion meter.
............ MONO Distortion (THD)
4. Repeat the adjustments of 2 and 3 several times.
Note : When replacing the ceramic filter, perform this adjustment.
Adjustment Location : See page 14.
Procedure :
FM stereo
Level meter Level meter
signal generator
connection reading (dB)
output channel
L-CH L-CH
A
B
R-CH L-CH Adjust VR703 for minimum
reading on level meter.
R-CH R-CH
C
D
L-CH R-CH Adjust VR703 for minimum
reading on level meter.
L-CH stereo separation :
A
–
B
R-CH stereo separation :
C
–
D
The separations of both channels should be equal.
Adjustment Location : See page 14.
FM Tuning Level Adjustment
Setting :
TUNER button : FM
Procedure :
1. Tune the set to 98.0 MHz.
2. Adjust VR701 so that the TUNED indicator goes on.
3. Confirm that the TUNED indicator goes off with FM RF SSG
output level set at 22 dB.
Adjustment Location : See page 14.
Carrier frequency : 98.0 MHz
Output level
: 60 dB (1 mV)
Mode : mono
Modulation : 1 kHz, 75 kHz deviation (100%)
FM RF SSG 1 kHz
high pass
filter
set
distortion meter
TP701
NULL terminal
digital voltmeter
(DC range)
FM RF SSG level meter
FM ANTENNA
75
Ω COAXIAL
set
FM RF SSG
Carrier frequency : 98.0 MHz
Output level
: 25 dB (17.8
µ
V)
Mode : mono
Modulation : no modulation
Carrier frequency : 98.0 MHz
Output level
: 60 dB (1 mV)
Mode : stereo
Modulation : main : 1 kHz, 37.5 kHz deviation (50%)
sub : 1 kHz, 37.5 kHz deviation (50%)
19 kHz pilot : 6.75 kHz deviation (9%)