Extra Information

Chapter 12: Tuning Utilities
94 ViewCast
The processing within a vectorscope and the display of the processed signals readily detects and
evaluates both phase and gain distortions of the chrominance.
Understand the Display
There are two parts to a vectorscope display: the graticule and the trace.
Table 25. Vectorscope Display Parts
Part Description
Graticule
• A scale you use to quantify the parameters of the signal under
examination.
• Work with a color bar signal.
• Remember, the color bar’s signal consists of brightness
information (luminance) and high frequency color information
(chrominance or chroma).
Trace The video signal itself. The demodulated chrominance signals
electronically generate it.
Each bar of the color bar’s signal creates a dot on the vectorscope's display. The position of these
dots remains relative to the boxes, or targets, on the graticule. The phase of the burst vector
represents the major indicators of the chrominance (color) signal's health.
Within the circle, you see six target shapes each containing smaller, sectioned shapes (Figure 151).
The smalle
r shapes designate where each dot of the color bar’s signal should fall if the chroma gain
and phase relationships are correct.
Figure 151. Vectorscope with Color Outside the Targets
To adjust the source, adjust the saturation on the capture card until you have it positioned inside the
targets. Refer to Figure 152 to see an example.