Tektronix 684A, 744A, 784A Verify the Time Base

Brief Procedures
4–10 TDS 684A, TDS 744A, & TDS 784A Service Manual
HSample mode displays an actively acquiring waveform on-screen.
(Note that there is noise present on the peaks of the square wave.)
HPeak Detect mode (TDS 7XXA only) displays an actively acquiring
waveform on-screen with the noise present in Sample mode “peak
detected.”
HHi Res mode (TDS 7XXA only) displays an actively acquiring
waveform on-screen with the noise that was present in Sample mode
reduced.
HEnvelope mode displays an actively acquiring waveform on-screen
with the noise displayed.
HAverage mode displays an actively acquiring waveform on-screen
with the noise reduced.
f. Test all channels: Repeat substeps a through e until all four input
channels are verified.
3. Remove the test hookup: Disconnect the probe from the channel input and
the probe-compensation terminals.
Equipment
Required One probe such as the P6245 or P6139A
Prerequisites None
1. Install the test hookup and preset the oscilloscope controls:
a. Hook up the signal source: Install the probe on CH 1. Connect the probe
tip to PROBE COMPENSATION SIGNAL on the front panel;
connect the probe ground to PROBE COMPENSATION GND. See
Figure 4–3 on page 4–8.
b. Initialize the oscilloscope:
HPress save/recall SETUP.
HPress the main-menu button Recall Factory Setup; then press the
side-menu button OK Confirm Factory Init.
c. Modify default settings:
HSet the vertical SCALE to 200 mV.
HSet the horizontal SCALE to 200 ms.
HPress CLEAR MENU to remove the menus from the screen.
2. Verify that the time base operates: Confirm the following statements.
Verify the Time Base