Jackson Labs PHASE STATION 53100A, User Manual

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PhaseStation 53100A User’s Manual V1.04 25-Apr-2022 59
For these reasons, Subtract global linear phase trend (frequency offset) ( Ctrl-o ) is not a
commonly-needed command. At first glance, Subtract global linear frequency trend
(drift line) ( Ctrl-l ) seems more useful:
Essentially, Subtract global linear frequency trend (drift line) ( Ctrl-l ) removes the
quadratic trend from the phase record, which has the effect of removing the
linear
trend from the frequency-difference plot. But there’s still an arbitrary offset in the
frequency-difference view that’s forcing the Y-axis scale to +/- 1E-9, and the artifacts
we’d like to examine are much smaller than this.
Navigating zoomed graphs
One strategy is to unlock the Y-axis with Trace → Phase/frequency Y axis unlocked in
zoom mode ( y ), and then use the left mouse button to drag a box around the trace.
When the button is released in the view at left, the result is the zoomed view at right:
TimeLab is designed to take full advantage of a PC mouse with three buttons and a
scroll wheel.
All of the graph types are “zoomable,” and you can always return to the
unmagnified view by right-clicking anywhere on the plot. Unlike the xDEV and noise
measurement displays, though, the phase- and frequency-difference measurement
views support additional navigation options. You can expand and contract the zoomed
area with the mouse wheel, or surf through the data by dragging with the middle
button.
Figure 22: Removal of linear frequency drift
Figure 23: Zooming in