Jackson Labs PHASE STATION 53100A, User Manual, Page: 205 / 225

PhaseStation 53100A User’s Manual V1.04 25-Apr-2022 205
The phase difference chart’s overall slope is a representation of the fractional difference
between the nominal and actual frequencies. In the example above, as in the earlier
show freqdiff example, the reported DUT input frequency is 10.1 MHz while the actual
frequency from the test source is just under 10.123456 MHz. The readings above
advance by about 2.322 milliseconds per second, corresponding to the fractional
frequency differences returned by the
show freqdiff command. Continuing the
example, if the nominal input frequency had been specified with set inputfreq
10.123456 ,
/inputfreq:10.123456
, or
/roundfreq:0.000001
, the slope of the phase
differences would be almost zero.
See the measurelinear and removelinear commands for information on calculating and
removing the linear trend from the phase-difference chart.
- show phaserate
Returns the phase data rate set by the
/phaserate
command-line parameter or the most
recent set phaserate command. See the description of the
/phaserate
command-line
parameter for more information.
- show referencefreq
Returns the reference frequency used for frequency counter and phase/frequency
difference calculations. See the description of the
/referencefreq
command-line
parameter for more information.
- show spectrum
Returns a list of offset frequencies and dBc/Hz values corresponding to the phase noise
spectrum in the measurement in progress (Figure 87):
Following the PSD data, the current instrument noise floor estimate will be returned
(Figure 88):
Figure 87