Panasonic AJSD955B - DVCPRO50 STUDIO DECK, Service Manual, Page: 186 / 562

ELE-45
5-2. PLL DC Adjustment
BOARD V IN (F2A)
TP TP450 (PLL DC)[A-2]
ADJ. VC450 (VCO DC)[B-2]
TAPE -----
INPUT Analog Component Signal
(100% Color Bar)
MODE EE
M. EQ Oscilloscope
SPEC. DC voltage : 0
±
0.1V
1.
Connect the scope to TP450. And adjust VC450
so that the DC voltage is in the specification.
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
(100% Color Bar)
MODE EE
M. EQ Oscilloscope
SPEC. A=
±
1usec
1. Set the Video Input Select Switch on the front
panel to “CMPST” (Composite).
2. Turn VR300 fully clockwise and confirm that
portion A is in the specification.
5-4. Composite SCH Detection
Adjustment
BOARD V IN (F2A)
TP TP870 (INCF)[B-4],
TP821(CF1), TP822(CF2)[A-2]
ADJ. VR301 (SCH)[B-1]
TAPE -----
INPUT CF Signal of Signal Generator
Analog Composite Signal
(100% Color Bar)
MODE EE
M. EQ Oscilloscope
SPEC. T1=T2
±
0.5msec
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 TP822 and CH2 to
TP821.
7. Adjust VR301 so that the low portion of TP822 is
positioned at the center of low portion at TP821.
(T1=T2
±
0.5msec
)
CF Pulse of
Signal Generator
TP870
INCOME CF0
(Positive)
TP870
INCOME CF0
(Negative)
Trigger
(Rising edge)
TP822
T1
Trigger (Falling edge)
T2
TP821
TP301 (5Vpp)
TP300 (500mVp-p)
A
Trigger
This portion