Casio SY-20B, Руководство по обслуживанию, Страница: 7 / 19

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3. Free running frequency adjustment
•
Conditions
(1) Signal
No signal (NTSC standard signal should be applied only at synchronous check)
(2) Signal level
Input electric field only at synchronous check: 70
±
3 dB
µ
(terminated with 75
Ω
resistance),
P/S = 10 dB
(3) Other conditions
US IF input only at synchronous check (input electric field with 75
Ω
termination).
Connect SYF terminal (CP729) and Vcc2-7 (CP701).
Power supply: Vcc1-1 (CP101) = 5.00
±
0.05 [V]
Room temperature: 20
±
10 [
°
C]
•
Adjustment
Monitoring HDB (CP305) with a frequency counter, adjust VR700 so that the frequency is 15.734
±
0.1 [kHz].
•
Caution
(1) Disconnect the wire between SYF terminal. Applying IF signal make sure that synchronization is normal
on the display.
(2) Use input signal pattern conforming CCIR standard.
•
Block diagram
L-PCB
SYF
Vcc2-7
HD
Frequency
Counter
Vcc1-1
IF signal
Signal
generator
Stabilizer