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ST-D50L
SECTION
2
ELECTRICAL
ADJUSTMENTS
@
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:
Vik
FM
RF SSG
STEREO MOD
[ as
|
(STEREO ADJ ONLY)
/
}
FM ANTENNA
terminal
CNP101
Ipin (R-CH)
3pin (L-CH)
Carrier frequency
: 98MHz
Modulation
i 1kHz
Deviation
: 40kHz (MONO only)
Output level
: 66dBu (at NULL/STEREO
Adjustment)
: 25dBu (at TUNED Adjustment)
Stereo MOD setting
Sub channel
1 38kHz
Deviation
: 16.25kHz
Pilot signal
2 19kHz
Deviation
1 7.5kHz
Modulation
¢ 1kHz—16.25kHz
deviation
1.
Discriminator Alignment (NULL check)
1.
Push the TUNING (+, —) button for 98MHz.
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
turns as shown below.
center of lighting-up ranges
lighting-up range
} OUTPUT
3.
Stereo Separation Adjustment
FM stereo
signal generator
output channel
VTVM connection
VTVM reading (dB)
®
® Adjust RV101
for minimum reading.
©
® Adjust RV101
for minimum reading.
L-CH Stereo separation : @—®
R-CH Stereo separation : ©—®
The separation of both channels should be equal.
Specification : 35dB
2-2.
AM SECTION ADJUSTMENTS
Setting:
VTVM
AM
;
j
30%. amplitude
wy ANTENNA terminal
CNP101
1.
LW Frequency Coverage Adjustment
Frequency display
153kHz
[Raisinenriae [iSO
2.
MW Frequency Coverage Adjustment
AEP, UK, WG model
531kHz
Adjustment part
IT model
522kHz
FE181(OSC)
Adjustment Location:
Frequency display
1602kHz
1611kHz
s60ak Hs
etait
L—)
a
in set
VT ® @V+02V
TUNER BOARD
® LW Voltage at test point
® MW
Voltage at test point
ST-D50L
3.
LW Tracking Adjustment
Frequency display
AEP, UK, WG model
153kHz
in set
IT model
144kHz
FEse2 (ANT)
Adjustment for a maximum reading on
VT VM.
4.
MW Tracking Adjustment
AEP, UK, WG model
—
53lkHz
522kHz
FE181 (ANT)
Frequency display
in set
IT model
Adjustment part
Adjust for a maximum reading on VTVM.
5.
Tuned Lighting-on Adjustment
1.
Push the TUNING
(+, —) button for LW: 281kHz (AEP/UK,
WG model) or 288kHz (IT model).
2.
Turn RV102 clockwise or counter clockwise and memorize the
lighting-up range of tuned indicator.
3.
Adjust RV102 at the center of the lighting-up range of both
turns as shown below.
center of lighting-up ranges
lighing-up range
At SSG OUTPUT 68dBuz
> -
Adjustment Location:
TUNER BOARD
CNP101
3
1
(L-CH)
(R-CH)
LW FREQUENCY COVERAGE
NULL
Adjustment
FM TUNED
Adjustment
TP101
test point
LW TRACKING
Adjustment
MW TRACKING Adjustment
NULL Adjustment
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