Sony Tektronix WFM 1125, Руководство пользователя

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Reference
3-26
WFM 1125 Option 0A/0B/0C/0D User Manual
The Vector graticule, shown in Figure 3–18, operates as a component vector-
scope. Each chrominance vector terminates as a bright dot in a target. The dot
brightness corresponds to the duration of the color bar. The distance from the
center box to the target box corresponds to the magnitude of the color being
measured. The dimension of each target box represents 2% (
±
14 mV) of a
700 mV P
b
and P
r
amplitude.
R
MG
B
CY
G
YL
Figure 3-18: Vector displaygraticule
With the Vector display, you can check the encoder accuracy for both phase and
amplitude errors proportional to those after composite encoding. When taking
measurements, make certain your source signal amplitude matches the Vector
graticule. For example, if the source is a 75% Color Bar signal, then choose the
75% graticule in the COLOR BARS of the VECTOR menu.
The displayed error is measured in terms of percent P
b
or P
r
since the signal may
never be encoded into composite PAL/NTSC where the errors are traditionally
expressed in terms of subcarrier magnitude and angle.
In the component domain there is no decoding required and therefore the color
bar transitions contain useful timing information. These timing differences
appear as looping or bowing of the transitions. It is possible to measure the
amount of bowing and to convert the results to a coarse delay value.
Vector Graticule
Phase and Amplitude
Measurements
Vector Timing
Measurements