Sencore VP300 - Manual (Page 16)

Page 15
Regulate
Pattern Description: A single pixel white border surrounds an interior picture area which
alternates between full white and full black.
Pattern Usage: Checks the regulation of CRT high-voltage and deflection power supply circuits.
The pattern alternately produces maximum and minimum CRT beam current. Ideally, these
current extremes should not cause the picture size to change. This can be judged by placing a
thumbnail next to one of the border lines to see the amount of displacement (avoids optical
effects from the alternating pattern). A one to two pixel shift is not noticeable in most picture
material to a typical viewer.
Checker
Pattern Description: Alternating picture areas of black and white in a checkerboard pattern.
Pattern Usage: Checks the regulation of CRT video drive power supply circuits. The pattern
produces abrupt, maximum changes in CRT video drive current. Ideally, this should not cause
the voltage supplied to the video drive circuits to change (good voltage regulation). If the power
supply does not have good regulation, it will cause softening or ringing of the vertical line
pattern transitions.
ANSI Gray