Lambda SR1, Operation Manual, Page: 24 / 317

SR1 Operation Manual 24
© 2014 Stanford Research Systems
Note how more detail is resolved inside the notch. Go back to the FFT analyzer on page 1 and press the
"Baseband" button to return the analyzer to it's full measurment range. We're now ready for the last step
in the demonstration.
Setting Up a Sweep
On page 1 click on the icon to open the sweep controller panel.We're going to sweep the amplitude
of our "distortion" sine wave and record the measured THD+N from the Time Domain Detector: Click on
the Sweep Source button to bring up the sweep source selection menu:
SR1 has 3 main types of sweep sources: Time Sweeps, where the sweep occurs at fixed time intervals,
Internal Sweeps, where the sweep occurs at fixed values of some internal parameter, and External
Sweeps, where the sweep occurs at fixed values of some externally measured parameter. Since we're
going to sweeping the amplitude of the sinewave we created in the generator, this will be an "Internal"
sweep. Open the Internal node on the tree, and then open the AnlgGen (Analog Generator) node to show
the associated parameters that can be swept. Note that there are two sine amplitudes and frequencies
shown, Sine(0) and Sine(1). That's because we created two sinewaves in the generator. The first, Sine
(0), refers to the 1 kHz fundamental. The second, Sine(1) is the "distortion" sinewave whose amplitude
we're going to sweep. Double-click on ChA:Sine(1):Amp to select it and return to the sweep panel: