Tektronix 1760 series, User Manual

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Basic Measurements
1760 Series Component Waveform/Vector Monitor User Manual
4-5
Making Waveform Measurements
Horizontal Sync Amplitude
The vertical scale at sync tip (40 IRE NTSC or --0.3 V PAL)
provides
±
2 and
±
4 IRE (
±
2 and
±
4 mV) for measuring sync
amplitude. Align the blanking level of a centered two
-
line
waveform display on the graticule baseline to place the sync
pulse directly over this structure. Measure sync amplitude
directly from the graticule, or use the voltage cursors.
Peak White
With the blanking signal level on the graticule baseline, the
amplitude of the 100% white reference of a color bar should
be on the 100 IRE (1 V) graticule line. With a
2 LINE
sweep
rate, use the
HORIZ POS
control to place the white reference
directly over the amplitude scale at graticule center. The
vertical markings there correspond to 2 IRE/division (10 mV/
division for PAL). Measure peak white directly from the
graticule or use the voltage cursors.
K-Factor Measurements
The boxed area in the upper left corner of the graticule is
scaled for 2% and 4% K--Factor ratings for precise tilt mea-
surements. This structure is designed to work with an 8
µ
s
half-amplitude duration (HAD) bar. The bar tilt measure-
ment structure can also be used to measure pulse-to-bar ratio.
Calibrated
X5 GAIN
can be used while making these measure-
ments; it increases resolution to 0.4% and 0.8%.
To use the NTSC vertical scale to make line-time distortion
and pulse-to-bar ratio measurements, position the signal
blanking level to the graticule baseline. Next, position the
center of the composite test signal bar to the center of the 2T
bar measurement box and check to see if insertion gain is
unity. If it is not, adjust the
VARIABLE GAIN
(enabled from the
GAIN MENU
) for exactly 100 IRE (700 mV PAL) of signal
amplitude from baseline to the middle of the white bar.