Basic Measurements
1760 SeriesComponent Waveform/Vector Monitor User Manu al
4-10
Making SC/H Phase Measurements(Option SC Only)
The SC/Hdi splay provides a vector display of the subcarrier-
to-horizontal-sync phase relationship. The burst vector and
the phase of the 50% point of the leading edge of sync are
displayed.
NTSC
Dual-Dot Display
When REF is set to internal, the 1760 has a dual-dot SC/H
display (Figure 4-6). The dots represent the 50% points of
horizontal sync.
To make a measurement, align the burst vector as shown in
Figure 4-6. The location of the horizontal sync dot is the
SC/H phase of the signal. With the dual dots, SC/H phase
range is limited to 180°, because the SC/H phase of a single
signal referencedto itself can only vary ±90°. At 180°,the
video signal again has a + field subcarrier phase seque nce,
making it “SC/H phased.”
Single-Dot Display
When REF is set to EXT, the 1760 has a single-dot display
(Figure4-7). This relative modeallows the comparison of
two signals,the selected INPUT and EXT REF. The ph ase shift
between the twosubcarriers can extend from 0°to 360°
A dot near 0°(relative to burst) indi cates the input is perfect-
ly SC/H-phasedwith the EXT REF input, a nd that the color
frames are properly matched. A phase reading of 180°indi-
cates that the INPUT and EXT REF color frames are not prope r-
ly matched.