You have a very simple "crystal radio" with the diode as the crystal. Look it up on Google for capacitor and inductor values.
The antenna must be very long, the ground must connect to a cold water pipe earth, the stations must be strong and local and the earphones must be high impedance. It doesn't have a power amplifier so it can't drive a speaker.
It is much too simple to have an oscillator. It is just a single tuned circuit (real radios have many) and an AM detector diode.
Oh yeah, use a fast diode, not a 1N400x rectifier that is too slow.