Sharp VC-780E - Page 27

if
Adjustment
of
NTSC
System
LP
Delay
Oscilloscope
NTSC LP Recording
Blank tape
CH1:TP701 H.SW.PULSE
CH2:TP702 CTL PULSE
R755 NTSCLP Delay
JT=11.2+ 1 msec.
1.
Insert
the
blank
tape
and
put
the
unit
in
the
NTSC
LP
Recording
mode.
2.
Make
sure
that
the
time
"T"
from
the
leading
edge
of
head
switching
pulse
to
the
leading
edge
of
control
pulse
at
TP702
(CTL
PULSE)
is
11.2
+
1
msec.
adi ee TP701 H.SW.PULSE
oc a TP702 CTL PULSE
|
|
bo —— 7 ——=4
T=14.2+ 1 msec.
Measuring
instrument
Tape used
Test point
Adjusting point
Specification
el Pere
Figure 2-5.
Adjustment of NTSC System EP Delay
Oscilloscope
NTSC EP Recording
Blank tape
CH1:TP701 H.SW.PULSE
CH2:TP702 CTL PULSE
R763 NTSC EP Delay
T= 16.7+ 1 msec.
1. Insert the blank tape and put the unit in the
NTSC EP Recording mode.
2. Make sure that the time "T" from the leading
edge of head switching pulse to the leading
edge of control pulse at TP702 (CTL PULSE) is
16.7 + Imsec. |
Now go to the X position adjustment.
oe in Se TP701 H.SW-.PULSE
Measuring
instrument
Tape used
Test point
Adjusting point
Specification
i era ia TP702 CTL PULSE
|
| 5 ; !
T=16.7+ 1 msec.
Figure 2-6.
A errs=10] 3
VC-790ET
Adjustment of PAL System playback switching point
Oscilloscope
Playback
Tracking button at center
Measuring
instrument
Tape used Alignment tape
(VROCPSV}
Test point CH-1; TP701
CH-2; Video output termina!
(CH-1 trigger slope switch at (+),
Internal trigger at CH-1 side)
R751 (PAL switching point
contro})
6.5 + 0.5H
Adjusting point
Specification
1. Insert the PAL System alignment tape (VROCPSV) and
put the unit in the playback mode.
2. Set the tracking button to the center position.
3.
Adjust
R751
(PAL
switching
point
contro!)
so
that
the
waveform
on
the
oscilloscope
screen
be as shown in Fig. 2-7.
CH-2
(Video output)
—
CH-1
CH-1; 2Vidiv 50usec/div
CH-2;:1Vidiv 50yusec/div
Figure 2-7.
Adjustment of NTSC System playback switching point
Oscilloscope
Playback
Tracking button at center
Tape used Alignment tape
(VROATSV)
Test point CH-1; TP701
CH-2; Video output terminal
{CH-1 trigger slope switch at (+),
Internal trigger at CH-1 side)
R753 (NTSC switching point
control)
6.5 = 0.5H
Measuring
instrument
Adjusting point
Specification
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