32
3. •
The following check with this pattern requires the aid of the oscillo-
scope.
Check the non-linearity of the video amplifier of the receiver with
the contrast control at maximum. Check that each step of this grey-
scale signal at the output of the video amplifier is equal. This can
easily be measured by comparing it on the dual beam oscilloscope
PHILIPS PM 3230 with the signal on socket "VIDEO".
Y
Y