Performance Tests
4–42 TDS 684A, TDS 744A, & TDS 784A Service Manual
Time Base System Checks
These procedures check those characteristics that relate to the Main and Delayed
time base system and are listed as checked under Warranted Characteristics in
Specifications.
Equipment
Required One time-mark generator (Item 13)
One 50 , precision coaxial cable (Item 5)
Prerequisites See page 4–15
50 Coaxial Cable
Time Mark
Generator Digitizing Oscilloscope
Output
Figure 4–11: Initial Test Hookup
1. Install the test hookup and preset the instrument controls:
a. Hook up the test-signal source: Connect, through a 50 W precision
coaxial cable, the time-mark output of a time-mark generator to CH 1.
Set the output of the generator for 10 ms markers.
b. Initialize the oscilloscope:
HPress save/recall SETUP. Press the main-menu button Recall
Factory Setup. Press the side-menu button OK Confirm Factory
Init.
c. Modify the initialized front-panel control settings:
HSet the vertical SCALE to 500 mV.
HPress VERTICAL MENU; then press the main-menu button
Coupling. Press the side-menu button to toggle it to the 50
setting.
HPress SET LEVEL TO 50%.
HUse the vertical POSITION knob to center the test signal on screen.

Check Accuracy for

Long-Term Sample Rate,

Delay Time, and Delta

Time Measurements