Purpose:
Determine the Video Head Switching Point during Playback.
Symptom of Misadjustment:
May cause Head Switching Noise and/or Vertical Jitter.
Test Point:
TP3001 (TV/VCR Main C.B.A.),
TP6205 (TV/VCR Main C.B.A.)
Adjustment:
PG SHIFTER (EVR)
Specification:
T = 6 H±1 H (0.38 ms±0.06 ms)
Input:
----------
Mode:
SP Playback
Equipment:
Oscilloscope, VHS Alignment Tape (VFMS0003H6)
1. Enter EVR PG Shifter Adjustment mode, refer to "HOW TO ENTER
EVR PG SHIFTER ADJUSTMENT MODE."
2. Connect the channel-1 scope probe to TP3001 and the channel-2
scope probe to TP6205. Use TP6205 as a trigger.
3. Adjust value so that the trailing edge of the head switching pulse
is placed 6 H±1 H (0.38 ms±0.06 ms) before the start of the vertical
sync pulse.
4. Release EVR PG Shifter Adjustment Mode.
The adjusted value will be written to Memory IC (IC6004).
Fig. E6
65