Beginner in electronics and radio frequencies in particular interest me. That said I'm having trouble understanding what components are used when. When I initially searched about radio frequencies, most knowledge articles said those frequencies are produced based off of a crystal oscillator that'll oscillate at a specific frequency.
However, in some DIY FM transmitter tutorials I've looked at a lot of the circuits don't incorporate any crystal. Rather, the circuits incorporate certain capacitors, and a coil (inductor?).
In this case are they doing more or less the same thing? For example, if I had a crystal oscillator generating a frequency at 88.1 MHz.. could I create an equivalent circuit using capacitors & a coil that also produces an 88.1 MHz signal? If no, why not? If yes, is there a reason to use one over the other?
Appreciate any responses.
Best Answer
Yes, you can build a oscillator with inductors and capacitors that will have the same frequency as your crystal oscillator. Using inductors and capacitors, you can reach frequencies much higher or much lower than you can reach with crystal oscillator.
The reason why crystal oscillators are used is because they have a much better frequency stability. Frequency stability does not matter much for an experimental DIY toy FM transmitter, but it does matter for many other uses.