For the technolab project, we chose to construct an FM radio. These were invented by Edwin Armstrong in the 1930s in the United States. Many people at the time were trying to broadcast high fidelity audio using wide bandwidth AM on VHF frequencies, and Armstrong was the first to commercially succeed. FM radios rely on electronic circuits and radio waves in order to function, but the majority of our work will rely on the circuitry. For this reason Chapter 27 which deals with Direct-Current (DC) circuits will be extremely important. We will be using YouTube as a major resource in ideas to design the radio and produce a working model, as well as other websites detailing how FM radio works in general. The toughest challenges will be acquiring all the necessary materials, mastering the practical skill of wiring circuits, and getting the radio to actually work correctly.
1x LM386: http://amzn.to/1Oo2iUa
1x 10kΩ, 1x 4.7kΩ Resistor: http://amzn.to/1Oo2mmI
1x Variable Capacitor (1-30pF): http://amzn.to/1Tlg49S
2x BF199 Transistor: http://amzn.to/1Oo2t1M
1x 25kΩ Potentiometer: http://amzn.to/1Oo2y5p
2x 100nF Capacitor: http://amzn.to/1TlgaOO
1x 10μF, 1x 470μF Capacitor: http://amzn.to/1Oo2GlB
0.65mm Copper Wiring: hopefully somewhere in the department
Antenna: also hopefully somewhere in the department
If not in department, will be ordered.
To build, we will first need to order the parts off of Amazon. To create the coil L1, we will need to use a short length of 0.65mm copper wiring and coil it four times around a 4mm item, probably a drill bit. We then will strip the ends of the insulation in order to utilize it on a breadboard. Once the other parts have been acquired, it is simply a process of piecing everything together on breadboards in the circuitry lab, and then clip the wires and solder them. Following the schematic will result in a correctly assembled circuit.
GreatScottLab. (2017, October 3). Build Your Own Crude FM Radio. Retrieved from https://www.instructables.com/id/Build-your-own-Crude-FM-Radio/