Lab 4: AM Detector

https://youtu.be/4lDX425nlX8

Purpose

Lab 4’s objectives are as follows:

• Breadboard and test simple diode detector, biased diode detector, and CFP detector circuits

• Add your chosen detector circuit to your radio’s audio amplifier and test

Each objective has its on part in lab to accomplish its goal. The first objective requires that three different circuits be built and the output analyzed on the o-scope. The second objective requires choosing the audio amplifier and detector then analyzing the output with the speaker and the o-scope.

Summary

The first part shows which of the detector is going to be best for the radio design. The output of the first detector, the simple diode detector, did not have an output showing that the input was detected well. The two to follow however detected the output well. I took a picture of my in lab results on the o-scope for these two detectors. As seen by the two pictures (Figure 4 and 5), the CFP detector follows the input much better and is therefore the detector I will use for the radio.

Given the previous lab data, the LM386 is the audio amplifier I chose. Given the data from this lab, I chose the CFP detector. Below is a video of the result. The detector was able to eliminate noise and pick up the AM signal. The audio amplifier made it where people can hear the detected signal.

Suggestion

I really enjoyed this lab. I felt like I saw for the first time how the parts were going to interact in order make a working radio. There are no suggestions.

Figure 1: Simple detector circuit

Figure 2: Biased Diode detector

Figure 3: CFP detector

Figure 4: output response of biased diode detector

Figure 5: Output response of CFP detector

Video 1: Video of the circuit/results of the combination of the LM386 and CFP detector