Sony ST-D50L - SECTION 2 ELECTRICAL ADJUSTMENTS; 2-1. FM Section Adjustment; 2-2. AM Section Adjustment

a.
e@
Repeat
the
procedures
in
each
adjustment
several
times,
and
the
frequency
coverage
and
tracking
adjustments
should
be
finally
done
by
the
trimmer
capacitors.
2-1. FM SECTION ADJUSTMENT
Setting:
FM RF SSG
STEREO MOD
SECTION 2
ELECTRICAL
ADJUSTMENTS
VTVM
VTVM connection
ST-D50L
3. Stereo Separation Adjustment
FM stereo
signal generator
output channel
VTVM reading (dB)
®
B® Adjust RV101
for minimum reading.
©
! L-CH Stereo separation : @—®
R-CH Stereo separation : O-—D
: 66dBu (at NULL/STEREO Adjustment)
1 25dBy (at TUNED Adjustment)
Output level
Stereo MOD setting
Sub channel 1 38kHz
Deviation : 16.25kHz
Pilot signal 2 19kHz
Deviation 1 7.5kHz
Modulation 1 1kHz—16.25kHz deviation
1. Discriminator Alignment (NULL check)
1. Push the TUNING (+, —) button for 98MHz.
2. Adjust T251 for 0V reading on the VTVM.
test point = TP101
2. Tuned Lighting-on Adjustment
1. Puch the TUNING (+, —) button for 98MHz.
2. Tune RV103 clockwise or counterclockwise and memorize the
lighting-up range of tuned indicator.
3. Adjust RV103 at the center of the lighting-up range of both
turms as shown below.
center of lighting-up ranges:
lighting-up range
SET Pas oes
l. | Specification : 35dB
(STEREO
ADJ
ONLY)
fo
}
:
FM ANTENNA terminal CNP1O1”
ome } OUTPUT
Spin (L-CH) Setting:
Carrier frequency : 98MHz
Modulation 2 LkHz
Deviation : 40kHz (MONO only) AM
RF SSG
30% amplitude
Modulation by
400Hz signal
/
AM ANTENNA terminal
® Adjust RV10]
for minimum reading.
The separation of both channels should be equal.
2-2. AM SECTION ADJUSTMENTS
CNPIO1
Ipin (R-CH)
3pin (L-CH) } Oat
1. LW Frequency Coverage Adjustment
Frequency display
in set
Adjustment part
Voltage at test point
AEP, UK, WG model
IT model
[Feiieos
[wre went [7]
153kHz 281kHz
2. MW Frequency Coverage Adjustment
Frequency display
in set
Adjustment part
Voltage test point
AEP, UK, WG mode!
IT model
Adjustment Location:
TUNER BOARD
TTintes!
as
at 7
522kHz 16l1kHz
FE181(OSC)
531kHz
VT ® OV+0.2V
© MW Voltage at test point
is ek sacs ie it casei asad: