In this lab, we will finish the RLC band-pass filter on page 2 of Lab 6 and plot results with the Matlab script lab7.m. Additional instructions will be given in the lab session, but the main objective is to plot the gain versus frequency (analytical and measured) for several inductor values. We will study the "frequency response" more carefully in ELEC 226.

Please go through the following steps during lab.

1. Measure the DC resistance, r, of each inductor and record the values.
2. Begin with the 10 mH inductor. Use the Matlab script to plot the analytical frequency response (amplitude gain versus frequency). Plot the frequency response with r=0 and with your measured value.
3. Simulate the circuit in PSpice and plot the output voltage versus frequency, with r=0 and with your measured value. Do the PSpice results agree with the Matlab plots?
4. Build the circuit with 10 mH inductor and measure the input and output voltage amplitudes at about 10 different frequencies.
   • Explain the variation in input voltage amplitude in terms of the Thevenin equivalent circuit of the source.
   • Enter your measured frequencies and amplitudes into the Matlab script and compare the measured gain with the analytical gain. Do they match? Is it necessary to include the inductor resistance (r) to get a good match?
   • Measure the resonant frequency of your circuit and compare with the analytical value and the PSpice result.
5. Repeat with the other inductor values. That is, measure the frequency response and make plots in Matlab. You can skip the PSpice for this part. Are the measured and analytical results consistent?
6. Add op amp buffer circuits to the input and output (why is this necessary?) and listen to music with different inductor values. How does it sound?

No lab report is required, but please discuss your results with the lab instructors. You do not have to print the plots, but show them on the monitor as you discuss the results. Thank you.