Filter
Top Products
Performance Verification
1780R-Series Service Manual
4–45
c. Rotate the Precision Measurement control to select Line 263 for the
1780R NTSC instrument. For PAL, go to parts e. and f.
d. Check that there is a one-half color display line located on the left side
of the Waveform CRT screen. Check that there is no Color Bar signal
displayed on the right side of the screen.
e. For the 1781R PAL instrument, select LINE SEL MENU–ON, FIELD 4
OF 8, and FIELD 1, 5, 3, 7 on the Waveform CRT. Turn the Precision
Measurement control to select Line 310.
f. Check that one color display line is located on the left side of the
Waveform CRT screen.
g. Press the LINE SELECT button to the Off position.
h. Leave the Color Bar and Black Burst signals connected to the instru-
ment.
37. Check RGB/YRGB Operation
Requirement: Square Wave or Staircase Input Amplitude: +10 V input will
result in a horizontal display of 6.7 divisions ±0.7 major division. Sweep
Repetition Rate: Field or line rate of displayed video as selected by the
WFM HORIZONTAL buttons.
a. Check that a Color Bar signal from the television test signal generator is
connected through a 75 W feed-through terminator to the 1780R-Series
CH A INPUT.
b. Check that a Black Burst signal is applied to the 1780R-Series EXT REF
connector and this connector is terminated into 75 W.
c. Select 1780R-Series WFM HORIZONTAL–ONE–LINE mode. Check
that RIGHT DISPLAY–WFM, INPUT–CH A, and REF EXT are
selected.
d. Use the 1780R-Series HORIZ POS and VERT POS controls to center
the display on the Waveform CRT.
e. Connect the RGB Parade Display Test Connector fixture (see Figure
4–4) to the 1780R-Series rear-panel REMOTE connector.
f. Check that the color bar display (or sweep) has shortened to 3.2 to 3.7
divisions when jumper A2J585 is set to its factory-set 4-step YRGB
Parade position (pins 2 & 3 are jumpered).
g. Use the 1780R-Series HORIZ POS control so that the color bar display
ends at the last major division mark on the right side of the Waveform
CRT graticule baseline. Note the waveform end location.