Tektronix 1760 - Manual (Page 112)

Basic Measurements
1760 Series Component Waveform/Vector Monitor User Manual
4-12
PAL
The 1761 uses a series of dots around the compass rose with
a single dot in a blanked area to denote sync (see Figure 4-8).
Place the burst vector at 0
°, align the burst vectors with the
graticule markings, and read the SC/H phase error as the
amount of sync dot offset from the the horizontal axis. The
input signal and the the
EXT REF signal are properly color
framed when the sync dot is within 90
° of the burst vector.
VECTOR PHASE
Figure 4-8.
PAL SC/H display.
SC/H R ---Y
SC/H phase can be viewed over a frame of video. Select
WAVEFORM display and FIELD sweep. Enter the FILTER menu
and select SC/H R---Y . For NTSC, stable SC/H is a horizontal
line as shown in Figure 4-10. (Figure 4-9 shows the same
display with a
LINE sweep selected.) A sample SC/H phase
error is shown in Figure 4-11. The flat lines indicate that
SC/H phase is stable over the entire frame. For PAL, SC/H is
a sine wave resulting from the 25 Hz offset (Figure 4-12).