Sony VX-14MW1E, Service Manual

Page: 66 / 80

31
F. PLAYBACK PHASE ADJUSTMENT (See Fig. 5-6)
Phase generator (PG) shifter decides the VIDEO HEAD switching point when a TAPE is played back.
In case the Phase generator (PG) shifter isn't correctly tuned, HEAD switching noise or vertical jitter may
occur.
a. Connect the PATH ADJ. FIXTURE to PT01 of the MAIN CIRCUIT BOARD.
b. Play the ALIGNMENT TAPE (COLOR BAR SIGNAL OR MONOSCOPE SIGNAL)
c. Connect the channel-1 scope probe to the S/W PULSE TEST PIN of the PATH ADJ. FIXTURE.
d. Connect the channel-2 scope probe(1V/div.) to the VIDEO OUT of the MAIN CIRCUIT BOARD.
e. Play back the ALIGNMENT TAPE.
f. Adjust the PG volume for time interval of 6.5H±0.5H between switching pulse and V-sync signal.
TEST POINTS
S/W PULSE TEST PIN PATH ADJ. FIXTURE
VIDEO OUT MAIN CIRCUIT BOARD
MEASURING EQUIPMENT OSCILLOSCOPE
ADJUSTMENT VR595 (PG SHIFTER) MAIN CIRCUIT BOARD
Fig. 5-6 PLAYBACK PHASE ADJUSTMENT