I’ve built one years ago, it is called a crystal radio.
Me too!.......
Researching this is a great way to harvest grant money from electrically illiterate politicians.
You can experiment and study forever and always be ALMOST at the point of the big breakthrough.
You can harvest more electricity from the voltage difference from ground level and any amount higher above the ground though.
I think this is what Tesla may have been working on.
Also a friend of mine has been producing usable electricity from ground up quartz crystals packed into copper pipe with a plastic insulator.
The crystal radio you built is a version of this.