Harmonics in output waveform of oscillator?

how to measure the harmonics in output voltage waveform of a voltage contolled oscillator using pspice simulator?

It′s relatively simple:

1.) Perform a TRAN-Analysis and measure exactly the period resp. frequnecy.
(Hint: Don′t use the PSPICE macro for this - it is not exact enough)
2.) Perform another TRAN-Analysis with FOURIER enabled (specify the fundamental carrier)
3.) Check the output file *.out. At the end of the file you will find the level of all harmonics and the calculated THD.

HINT: Don′t use the FOURIER option in PROBE (it is a FFT and very roughly)