Specifications

156 Chapter 15
Concepts
Trigger Concepts
Concepts
Trigger Settings and Fast Time Domain Sweeps
Trigger delay can be used to move the sweep trigger point arbitrarily
across a given TV line or lines to allow closer examination of waveform
patterns (Press
Trig , Trig Delay, and enter a delay time).
In fast sweeps (20
µs to less than 5 ms), there may be up to one trace
point of variation in the start time of the waveform digitalization
process with respect to the actual TV trigger pulse. This randomness
leads to the appearance of visual jitter on the LCD display of the
analyzer. In this situation, video averaging may be used (N = 5, for
example) to improve the “visual stability” of the displayed waveform.
This type of jitter does not occur when sweep times are set greater than
or equal to 5 ms where digitalization begins less than 100 ns after the
trigger pulse in that mode (much less than 1 trace point of jitter).