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Adjustment Procedures
1780R-Series Service Manual
5–55
h. Connect the output of the function generator to the test oscilloscope
vertical amplifier input. Set the generator controls for 1 kHz, 0 V to
+10 V, square waves as displayed on the test oscilloscope CRT.
i. Disconnect the function generator output signal from the test oscillo-
scope. Connect the generator output square wave signal to the RGB
Parade Display Test Connector input BNC connector.
j. Adjust RGB/YRGB Staircase Comp (A5C195) for no smearing.
k. Disconnect the generator square wave signal and RGB Parade Display
Test Connector from the instrument. Leave the Color Bar and Black
Burst signals connected to the instrument.
43. Adjust Dynamic Focus
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.
c. Select LEFT DISPLAY-VECT and REF-EXT. Press the LINE SELECT
button to turn on this function. Touch the LINE SEL MENU-ON pad to
display the menu on the Vectorscope CRT. Select VERT-1H,
WFM=VECT-YES, FIELD 2 OF 4 for NTSC (4 OF 8 for PAL),
WFM-1H, VECT LSEL-ON, and WFM LSEL-ON.
d. Select WFM HORIZONTAL-TWO-LINE. Check that RIGHT DIS-
PLAY-WFM is selected.
e. Use the Precision Measurement control to select an active video line that
displays the Color Bar signal.
f. Select LINE SEL MENU-OFF. Adjust FOCUS control for best trace
definition.
g. Adjust the INTENSITY control along with the WFM Line Select Focus
(A16R350) for best trace definition on the Waveform CRT display.
h. Press the button below the Vectorscope CRT.
i. Adjust the INTENSITY control along with the Vector Line Select Focus
(A3R384) for best trace definition on the Vectorscope CRT.
NOTE. A3R384 adjustment range is limited. Adjust for roundest dots on the
Vectorscope CRT display.