Tektronix 684A, 744A, 784A Check Accuracy, Trigger-Level or Threshold, DC Coupled

Performance Tests
4–48 TDS 684A, TDS 744A, & TDS 784A Service Manual
HCHECK that the Lower Limit readout, after the oscilloscope stops
triggering, is within 1 ms to 3 ms, inclusive, for the TDS 684A or is
within 1.9 ms to 2.1 ms, inclusive, for the TDS 7XXA.
HEnter time on test record.
HUse the keypad to return the Lower Limit to 500 ns and reestablish
triggering.
HPress the side-menu button Upper Limit; then use the general
purpose knob to slowly decrease the Upper Limit readout until
triggering stops.
HCHECK that the Upper Limit readout, after the oscilloscope loses
triggering, is within 1 ms to 3 ms, inclusive, for the TDS 684A or is
within 1.9 ms to 2.1 ms, inclusive, for the TDS 7XXA.
HEnter time on test record.
4. Disconnect the hookup: Disconnect the cable from the generator output at
the input connector of CH 1.
Equipment
Required One DC calibration generator (Item 9)
One BNC T connector (Item 7)
Two 50 W, precision coaxial cables (Item 5)
Prerequisites See page 4–15.
DC Calibrator
50 W Coaxial Cables
Dual Banana to
BNC Adapters
BNC T
Connector
Digitizing Oscilloscope
Figure 4–15: Initial Test Hookup
1. Install the test hookup and preset the instrument controls:
a. Hook up the test-signal source:
HSet the output of the DC calibration generator to 0 volts.
Check Accuracy,
Trigger-Level or
Threshold, DC Coupled