HP 54645A User's And Service Manual page 188

5 Set the time base to 200 s/div, then center the signal on the display
with the delay knob (delay about 800 s).
Press
6
7
Set the delayed sweep to 20 s/div, then set the expanded portion
over the VITS (delay about 988.8 s).
Figure 6-7
Second VITS Displayed
This figure shows the second vertical interval test signals displayed with
delayed sweep.
Using Option 005 Enhanced TV/Video Trigger (HP 54645A)
, then press the
Main/Delayed
To analyze video waveforms with Option 005
softkey.
Delayed
6-13