Daewoo DR-C912B, Руководство по обслуживанию

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41
ELECTRICAL ADJUSTMENT
PG (Pulse Generator) Shifter Adjustment (Fig. 3)
Test Points: PT01 PIN
#
Main
Video Out Jack Rear Panel
Adjust: REC SWITCH Main
The Pulse Generator (PG) Shifter determines the video head switching
point during playback. Misadjustment of the PG Shifter may cause head
switching noise in the picture and/or vertical jitter.
1. Load the instrument with an alignment tape and play back the color
bar signal or monoscope signal.
2. Connect Path Fixture to PT01.
3. Connect channel-1 scope probe (1V/div.: 50
µ
sec/div.) to PT01 PIN
#
. Trigger the scope on channel-1.
4. Connect channel-2 scope probe (1V/div.) to the Video Out Jack.
5. Set the scope to (-) slope and press the REC SW, the alignment is
performed automatically. Confirm that the trailing edge of the SW
30Hz pulse is placed 6.5H–0.5H (horizontal) lines before the start of
vertical sync pulse.
SWITCHING
SW30Hz
PULSE
VIDEO
OUTPUT
V. SYNC
6.5H±0.5
Fig. 3 - Automatic PG Shifter Adjustment