I want to make a simple wireless device (radio?) that consists of only two copper coils where changing magnetic flux in primary coil causes a current flow in the secondary. I tried, once, with LEDs and 3-Volt DC batteries, but failed. So any insights or plans are appreciated. I would also like to give it some range (like, 2 meters).
Moreover, how would this device of mine will be different than a radio? Because, to my understanding, the changing flux here also causes electromagnetic waves to travel away from the coil. So does this mean that the basic principle behind the both is same?
My own knowledge about all this, as this writing would suggest, is very limited. I could not find any designs or schematics on the internet simple enough to follow and understand. Any help therefore is appreciated.