User's Manual

Performance Tests
TDS 684A, TDS 744A, & TDS 784A Service Manual
4–43
H Set the horizontal SCALE of the Main time base to 1 ms.
H Press TRIGGER MENU; then press the main-menu button Mode
& Holdoff. Press the side-menu button Normal.
2. Confirm Main and Delayed time bases are within limits for accuracies:
a. Display the test signal:
H Align the trigger T to the center vertical graticule line by adjusting
the horizontal POSITION. See Figure 4–12 on page 4–44.
H Press HORIZONTAL MENU.
H Set horizontal modes. To do this, press the main-menu button Time
Base. Press the side-menu buttons Delayed Only and Delayed Runs
After Main. See Figure 4–12.
b. Measure the test signal:
H Set the horizontal SCALE of the D (delayed) time base to 500 ns for
the TDS 684A or to 100 ns for the TDS 7XXA.
H Set delayed time to 10 ms. Do this on the keypad by pressing 10,
then SHIFT, then m followed by ENTER.)
c. Check long-term sample rate and delay time accuracies against limits:
H CHECK that the rising edge of the marker crosses the center
horizontal graticule line at a point within either ±2.0, for the TDS
684A, or ±2.5, for the TDS 7XXA, divisions of center graticule. See
Figure 4–12.
H Enter number of divisions on test record.