The coil you made is completely mashed out of shape. It is not a proper FM demodulator, and it does not use a typical RF receiver or amplifier. No other way of building that circuit will work properly. That means right down to the size of the perfboard and the placement of the components. If you want to build that circuit, then you absolutely must build it as shown and described. And, that's ignoring the inductance of your long wires. It will be pretty much impossible to tune it to anywhere close to the needed frequency - if it can work at all. The capacitors and inductors used in the circuit have values close to the capacitance between rows on the breadboard and the inductance in the rows. That circuit will be twitchy (very sensitive to the presence of other objects close by) and very sensitive to stray capacitance and inductance. It also doesn't mean you can build it on a breadboard. If this is the video you followed, then it is probable that it will work if properly built and tuned. Many AM receiver circuits are simple (few components, few connections) to assemble but complicated to use (setup, tuning, antenna placement, etc.) In either case, follow the instructions exactly. Purchase exactly the parts recommended by the author. Your best bet is to buy a kit (one that has a good set of instructions and also explains the theory behind radio and the receiving circuit.)Īlternatively, find a project description that includes a good explanation and a parts list. Your circuit doesn't resemble any typical AM receiver that I've ever seen, nor does it resemble an FM receiver. (That is, pins in a row that are connected together will act like an open circuit at high frequencies, and adjacent rows will act like they are shorted together.) The individual pin rows act like inductors at those frequencies, and the rows act like there are capacitors connecting them. That is much too high to run on a breadboard. That's low enough that you could expect the circuit to work on a breadboard.Ĭommercial FM broadcast in the USA is from 88 megahertz to 108 megahertz. Commercial broadcast AM stations in the USA are on frequencies from 560 kilohertz to 1.695 megahertz. It should be possible to build an AM receiver on a breadboard. ![]() Your "FM receiver" is at best an AM receiver. ![]() After I used my screwdriver, I didn't hear anything, everything was quiet. I filtered high-frequency noise using low-pass filter and I only heard some small humming noise there. Here is the screen of my variable capacitor:Īnd the way it's all connected on breadboard could be seen here: Can anyone tell me? And is there a way I could vary my variable capacitor with a metal screwdriver? I don't have any plastic ones. I've been thinking a lot how I am supposed to connect it properly. Then I realised I also might have connected my circuit wrongly. I don't know if it is enough, but I don't think so. I wanted to ask why my radio is not picking up any signals.Īt first I thought of having a very small antenna for this purpose. I know it's not quite appropriate to make this stuff on breadboard, but if it works, I'll move in on the board and solder it.
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