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3.Free running frequency adjustment
•
Conditions
(1) Signal
No signal (PAL standard signal should be applied only at synchronous check)
(2) Signal level
Input electric field only at synchronous check: 70 dB
µ
(terminated with 75-ohm resistance),
P/S = 7 dB
(3) Other conditions
UK IF input only at synchronous check (input electric field with 75-ohm termination).
Connect SYF terminal (CP729) and VCC2-7.
Power supply: Vcc1-1 = 5.0
±
0.05 [V]
Room temperature: 20
±
10 [
°
C]
•
Adjustment
Monitoring HDB (CP305) with a frequency counter, adjust VR700 so that the frequency is 15.625
±
0.1 [kHz].
•
Caution
(1) Disconnect the wire between SYF terminal and VCC2-7.
Applying IF signal make sure that synchronization is normal on the display.
(2) Use input signal pattern conforming UK standard.
•
Block diagram
4.Contrast adjustment
•
Conditions
(1) Signal
Broadcasting system: I
Color system: PAL color bar
(2) Signal level
Input electric field: 70 dB
µ
(terminated with 75-ohm resistance), P/S = 7 dB
(3) Other conditions
UK IF input (input electric field should be terminated with 75-ohm resistance).
Apply voltage of Vcc1-1 = 5.0
±
0.05 [V]
•
Adjustment
Connect color terminal (CP320) to GND (CP300) so that screen becomes black and white. Adjust
contrast pot VR300 so that the voltage between pedestal level and white level of B signal (CP740) is
0.80
±
0.05 [Vp-p].
L-PCB
VCC1-1
VCC2-7
SYF
HD
Stabilizer
Signal
generator
Frequency
Counter
