 Capturing signals |  Measuring a simple sine wave |
|---|---|
 Modulated wave |  50% modulation |
 100% Modulation |  |
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The purposes of this lab (click title to see lab) are to become familiar with lab test equipment, generate and measure sine waves, become familiar with amplitude modulation, generate and measure an AM signal.
The lab equipment that I was familiarized include the Hewlett-Packard 3311A function generator, BNC-to-banana adapters, Pomona 20 dB attenuators, the BK Precision 4040 function generator, the Tektronix TDS2022 oscilloscope, the Tenma DC power supply, and the Omega HHM90 digital multimeter (DMM). This equipment is a bit different from the virtual equipment on the NI ELVIS II usually used for my earlier electrical lab courses. It feels more involved and pushes you to understand what you are actually doing on a deeper level.
Once I became familiar with some of the basic functionality of the lab equipment I will be using this semester, I learned how to measure waveforms and spectrums of AM signals. I started by using the 3311A to output a simple sine wave and measured it using the oscilloscope. After mesuring the signal with the DMM, I realized that digital multimeters measure the RMS values of AC signals. I repeated this proccess with the BK precision 4040.
Next, I created AM signals with the two funtion generators and measured them. While doing this I learned that using forced attenuation allows the measurement of signals that are too normally large to measure. I also learned why someone would measure the frequency spectrum of a signal. When AM signals are recieved, they only detect the difference between the peak and minimum amplitudes to extract the intelligence frequency rather than recieving the intelligence frequency itself. .