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Performance Verification
4–44
1780R-Series Service Manual
n. Set the TIME CURSORS button to Off and the MAGNIFIER to OFF.
35. Check Variable Sweep Range
Requirement: Range: >±20%.
a. Connect the television test signal generator Color Bar signal through a
75 W feed-through terminator to the 1780R-Series CH A INPUT
connector.
b. Set the Select WFM HORIZONTAL THREE–LINE mode.
c. Note the number of divisions that the three-line waveform display
occupies.
d. Set the VAR/SLOW button to VAR.
e. Rotate the variable SWEEP RATE control counterclockwise to shorten
the variable sweep length. Use the HORIZ POS control to position the
display horizontally so the graticule baseline can be used to measure the
width of the three-line waveform display.
f. Check that the three-line waveform display occupies a width that is 20%
or less than the number of divisions noted in part c. of this step.
g. Set the VAR/SLOW button to Off.
h. Note the number of divisions that a one-line waveform occupies.
i. Set the VAR/SLOW button to VAR.
j. Rotate the variable SWEEP RATE control clockwise to the longest
variable sweep length.
k. Check that one line of the three-line waveform display occupies a width
that is 20% or more greater than the number of divisions noted in part h.
of this step.
l. Select WFM HORIZONTAL TWO–LINE sweep and set the VAR/
SLOW button to Off.
m. Leave the Color Bar signal connected to CH A INPUT.
36. Check Line Selection
Requirement: Range: Full Field. Field Selection: 1 of 4 for NTSC or 1 of 8
for PAL. Even or Odd and All Fields.
a. Check that a Color Bar signal is applied to the CH A INPUT.
b. Press the LINE SELECT button and check that WFM HORIZONTAL
TWO–LINE is selected. Check that FIELD 1,3 pad (for NTSC) is
selected on the Waveform CRT menu. (For PAL, select FIELD 1,5,3,7.)