Panasonic AJSD955B - DVCPRO50 STUDIO DECK, Руководство по обслуживанию, Страница: 174 / 562

ELE-33
5-3. Composite Color
Demodulation Timing
Adjustment
BOARD V IN (F2A)
TP TP300(APC)[C-1], TP301(BGP)[C-1]
ADJ. VR300 (RSTH)[B-1]
TAPE -----
INPUT Analog Composite Signal
(75% Color Bar with 7.5% Setup)
MODE EE
M. EQ Oscilloscope
SPEC. Center
1. Set the Video Input Select Switch on the front
panel to “CMPST” (Composite).
2. Open the SERVICE MENU. (Refer to SEC1
Service Information.)
3. Select the C00: VIN ADJUST and press the
“SET” button to open the VIN ADJUST MENU.
4. Select C-2: CMPST ADJUST and press the
“SET” button to open the CMPST ADJUST menu.
5. Set the numerical value of the C09: SITE CAXIS
to 127.
6. Connect the scope CH1 to TP301 and CH2 to
TP300.
7. Adjust VR300 so that the timing of the center
portion of these pulses becomes same timing as
shown in figure.
8. Set C09: SITE CAXIS to 0(zero).
5-4. Composite SCH Detection
Adjustment
BOARD V IN (F2A)
TP TP870 (INCF)[B-4],
TP824(SCHP)[A-3]
ADJ. VR301 (SCH)[B-1]
TAPE -----
INPUT CF Signal of Signal Generator
Analog Composite Signal
(75% Color Bar with 7.5% Setup)
MODE EE
M. EQ Oscilloscope
SPEC. T=55
±
0.5nsec
1. Set the Video Input Select Switch on the front
panel to “CMPST” (Composite).
2. Connect the scope CH1 to TP870 and CH2 to CF
Pulse of the signal generator. And set the trigger
channel to CH2. (Triggered by rising edge.)
3. Set VR301 fully counterclockwise.
4. If income CF0 pulse of the TP870 is positive
pulse, turn the VR301 clockwise until changing
from positive to negative as shown bellow.
5. Turn the VR301 clockwise slowly until just
changing from negative to positive as shown
below.
6.
Connect the scope CH1 to TP824 and trigger by
falling edge.
7. Turn the VR301 clockwise slowly until the rising
edge of the TP824 moves from "A" to "B" as
shown below. The time difference "T" should be
in the specification.
CF Pulse of
Signal Generator
TP870
INCOME CF0
(Positive)
TP870
INCOME CF0
(Negative)
Trigger
(Rising edge)
TP301 (5Vpp)
TP300 (50mVp-p)
Trigger
Center
Expansion
T
Trigger (Falling edge)
A
TP824
B