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/* Building & Testing the Colpitts Oscillator */
Before running a Transient Test of your Colpitts oscillator, first run a DC Bias Test to find the DC operating point of the BJT. The results of the DC bias test are shown in the opposite figure. According to this table, the quiescent collector current I<sub>C</sub> is 2.985mA. The Barkhausen criterion in this case is thus satisfied:
<math>A \beta(s) = \left( \frac{1nF}{16nF} \right). \left( \frac{2.985e985\times 10^{-3}}{26\times 10^{26e-3}} \right). 2e3 2\times 10^3 = 14.351 \ge 1</math>
Now run a Transient Test of your oscillator circuit with start and stop times set at 0 and 100μs, respectively, and a Step Ceiling equal to 1ns. The output voltage graph is shown in the figure below. The output signal oscillates between 2V and 14V. A signal period of almost 1μs can be measured, which corresponds to an oscillation frequency of 1MHz.
