Tektronix 1760 series, User Manual

Page: 106 / 180

Basic Measurements
1760 Series Component Waveform/Vector Monitor User Manual
4-6
To measure the K
--
Factor line-time distortion, measure the
largest deviation of the bar top (tilt or rounding) within the
structure. The solid outer box equals a 4% K--Factor, while
the dashed line inner box equals a 2% K--Factor. For signals
with a bar half-amplitude duration that exceeds 18
s (8 s
PAL), measure the bar top in increments by positioning the
bar to the left or right of the leading or trailing edge. The
first and last 1
s of the bar should be disregarded.
Pulse-to-bar K--Factor measurements are made by normaliz-
ing bar amplitude (100 IRE or 1V) and adjusting the
HORIZ
POS
control to position the pulse on the line-time distortion
structure. Use the
VAR GAIN
(see
CONFIG—GAIN
menu, page
3-26) to adjust signal amplitude.
Make sure that the center of the bar is at 100 IRE (1 Volt
PAL) when blanking level is at 0 IRE (use
VARIABLE GAIN
to
adjust gain, if necessary). Use the
HORIZ POS
control to
place the 2T pulse over the center of the boxed measurement
area and measure its amplitude. When the top of the pulse
falls within the dashed lines, the K--Factor equals 2% or less.
Vector Graticule
The
VECTOR
display permits measurements of hue in terms
of the relative phase of the chrominance signal with respect
to the color burst. Relative amplitude of chrominance to
burst is expressed in terms of the displacement from center
(radial dimension of amplitude).
The vector graticule is combined with the waveform grati-
cule.
The NTSC and PAL vector graticules contain burst and vec-
tor targets; the dual-standard graticules contain burst and
vector targets for both NTSC and PAL standards. The vector
targets can be used with either 75% or 100% amplitude color
bar signals. The selection is made through the
CONFIG—VEC-
TOR
menu, described on page 3-21.