Sharp VC-780E - Page 33

Adjustment of APC
Measuring
instrument
Adjusting point R506 (APC control)
4.433619MHz + 20Hz.
1. Insert the alignment tape (VROCPSV) and place
the unit to the playback mode.
2. Connect the frequency counter to TP501.
Adjust R506 (APC control) so that the counter
' reading be 4.433619MHz + 20Hz.
@ ADJUSTMENT OF SECAM SUB CHROMA CIRCUIT
Adjustment of record mode
Record mode
Sescea vive |
1
Set the unit in the record mode.
2. Apply a SECAM colour bar signal to the unit and
record it.
3. Observe the output of TP5706 with an
osilloscope, and adjust T5703 so that the
chroma signal becomes flat as shown in Fig. 2-
17.
Frequency counter
Playback
Alignment tape (VROCPSV)
Oscilloscope
TP5706
a
=
bP
GY
Mm
z
=
>
l iiinieel
Figure 2-17.
A Ore £510) =
VC-7S0ET
Adjusting of sync gate in the record mode
Measuring instrument
Mode selection
Oscilloscope
Record mode
Input signal Colour bar signal
TP5707
Video output terminal
| R5814 (Sync gate adj.)
R5815 (Sync gate adj.)
Measuring point
Adjusting control
Specified
value
Ty:
1.5psec
Nn a a
T2:5.6psec
1.
Apply
a
SECAM
colour
bar
signal
to
the.
unit
and
record
it.
;
2. Connect an oscilloscope to TP5702 and video
output terminal and make sure that the chroma
signal output is just as shown in Fig. 2-18.
3. Adjust R5814 and R5815 so that the intervals T1
and T2 in the waveform of the output at
TP5705 and those in the video output
waveform should be corresponding to each
other.
TPS707
Video Oulpul
Figure 2-18.
Adjustment of recording equalizer (15702)
1 Adjust T5702 so that the output at point @
should be as shown in Fig. 2-19.
TP5707
MOTISA
@
Figure 2-19.