Sharp SX68JS10, Service Manual

Page: 10 / 62

SX68JS10
10
SOUND LEVEL ADJUSTMENT
NO. Adjustment part Adjusting procedure and conditions Waveform and others
1 SUB VOL (Bus
adjustment)
1
Receive E-12ch (PAL colour bar). Signal con-
tent: 400Hz 100% Mod.
2
Connect the probe of the meter (*) to (SI) con-
nector.
3
Select SUB-VOL in the service mode.
4
Adjust the SUB-VOL data (At L-ch).
Adjustment value : 11.2
±
0.3Vrms
Adjustment value : 11.2 – 0.05Vrms
1
Receive E-12CH (PAL colour bar).
2
Maximize the sound volume to verify that the
sound is output from the speaker. Then, set
the non-signal state.
3
At this time, verify that the audio mute oper-
ates.
4
After checking the operation, set the sound
volume to be the smallest.
Note:
* SPATIALIZER OFF
* S-Normal state
* S-VOL Max
* S-BOOSTER OFF
* : Use the multimeter or similar
which sufficiently attenuates the
high-band frequency (bigger than
100kHz).
SIF (IGR) ADJUSTMENT
NO. Adjustment part Adjusting procedure and conditions Waveform and others
1
VCO COIL
T2300
1
Receive E-69CH (PAL colour bar).
(Set the receiving frequency at AFT OFF 855.25
MHz.)
2
Connect the digital voltmeter to TP202 (in the
main unit).
3
Verify that it is turned counterclockwise to 0V
and clockwise to 5V, and adjust T2300 to make
the DC voltage of TP202 become 2.5
±
0.1V in
the range.
* Single-unit adjustment
Vcc
5V
±
0.1V
IF input frequency 38.9MHz
±
10kHz
Control it under these conditions.
Adjust T2300 to make the DC voltage of TP2300(in
the NICAM unit) become 2.5
±
0.1V.
After single-unit adjustment, check the practical
setup.
Align the receiving frequency to the select chan-
nel frequency. (AFT OFF)
The checked voltage must be 2.5 V
±
1.0V.
(Take care that
±
1.0 is considered for the Vcc dif-
ference between the single unit and unit, Fo differ-
ence and so on, but is not the adjustment preci-
sion.)
2 Noise mute
check