Performance Tests
4-50
TDS 420A, TDS 430A & TDS 460A Service Manual
2. Confirm the video trigger system is within limits:
a. Display the test signal:
H Set video generator to NTSC format.
H Set the output of the generator for a five step ramp with color burst.
H Press SET TO 50%. Use the trigger MAIN LEVEL knob to
stabilize the display as required.
H Press TRIGGER MENU.
H Press the main menu button Mode & Holdoff. Then press the side
menu button Normal.
b. Fine adjust the sync pulse amplitude: The amplitude of the TV
waveform should now be about 2 divisions pk-pk. Do the following
subparts to fine adjust the vertical gain until the sync pulses measure
exactly 0.6 divisions peak-to-peak using the graticule:
H Press VERTICAL MENU.
H Press the main menu button Fine Scale.
H Use the General P urpose knob, adjust the fine gain until the sync
pulse amplitude is 0.6 divisions measured using the graticule (see
Figure 4--19).
To Next Page
Loading...
