Sharp VT-3418X - Page 44

WTest points layout of Y/C Unit.
---___- _
.- _-_--- ---- __.-
r
0
05512
02223
0
R2201
A2203
PB-Y LEVEL
GJ yyPT
TP2205 CLIP
R2204
lP2206 C&D
DEVIATION
IC220 I,^\
FL5501
cl
El
TP2201 PB CHROMA
lP2202 HEAD SWITCHING PULSE
lP2203 GND
TP2204 REC SIGNAL
Figure 2-4.
Adjustment of white clip
-
Measuring
instrument
Mode
Input signal
Test point
Control
Specification
Osci I loscope
E-E or Record
PAL colour bar (1 .OVp-p)
TP2205(Signal), TP2206(G N D)
R2203 white clip control
190 + 5% (See note below)
1. Connect the oscilloscope to test points
TP2205(Sig.) and TP2206(GND).
2. Feed the colour bar signal to the VIDEO IN jack
and put the unit in AV input mode.
3. Adjust R2203 so that the overshoot of the video
signal is clipped at 190% as shown in Figure 2-5.
Note:
From sync tip to white peak, the level is 100%.
The white clip level is 90% above the white level.
(There is no dark clip adjustment.)
. . . .
.:.:
$2
l-
I
I SYNCTIP
I
100% WHITE
-.................................w
WHITE CLIP LEVEL
Figure 2-5.
44