What are crystals used for in radio? I think I sort of know the answer to this but I would like a more detailed explanation. To my current understanding, piezoelectric crystals are used to modulate between mechanical energy and electric energy.
I may not have stated that entirely correctly but what it essentially does is take a sound wave and convert it to an electrical signal to be broadcast. Then, on the receiving end, a crystal of similar frequency is used to reverse this process, turning electrical waves into mechanical waves that can then be made audible?
So, the crystals aren't actually used to receive any signal, correct? What I mean by that is that the signal is taken in by the antenna, not any crystal? Don't the crystals determine the carrier frequency being broadcast on though?
What got me interested in this is I read that there are piezoelectric crystals in the inner ear. Would it be possible to broadcast an RF signal to the inner ear? Trying to get the details of RF systems down.