The Bode Plotter would not accept the oscillator’s own oscillation as the circuit excitation. I had to do something more (Figure 2). Figure 2 A successful analysis attempt. I had to add V2 and R4 as ...

Figure 1. Example of a circuit for a second-order low-pass filter. The circuit will be stimulated with a sine wave. This requires an AC sweep, which can be found under the AC Analysis tab in the menu ...

This is great, but there is a SPICE booby trap waiting for the unwary user of the Bode plotter. Please consider this zero-frequency IF circuit from my Living Analog blog entitled, Zero frequency IF.