Hi, I was just wondering how these electronic components connected together on a PCB with an antenna produce frequencies. 1. I found schematics for a circuit that transmits FM but it doesnt actually explain anything, you basically connect a microphone, a transister, a variable resistor, some fixed resistors, some capacitors which are connected to an antenna along with a coil of copper wire(whats this for ?). I just dont understand how these things produce a frequency that can transmit my voice. Also further reading shows that you can take the microphone out and emit noise which if at the right frequency would disrupt the signal of a nearby radio tuned at that frequency now I know why this would happen because those noise will cancel out the signal received by the radio something I learnt in A-Level physics. 2. Why not just connect a capacitor to a copper coil around iron to emit frequencies much like EMPs but at low energy so it does fry anything just emit certain frequencies ? Again I am also confused about EMPs, do they work because the electrons discharged from the capacitor go round in a coil and just jump out in the air ? if so why not just use a straight wire why do we have to use a coil ? I would appreciate if someone could explain to me the concept behind these devices. I am getting more and more interested in RF engineering even though I am doing mechanical. Cheers.