![](https://www.popsci.com/wp-content/uploads/2019/03/18/ENZZJIYEKS7VPYWVWSAKFVHCC4.png?quality=85&w=376)
![](https://www.popsci.com/wp-content/uploads/2019/03/18/ENZZJIYEKS7VPYWVWSAKFVHCC4.png?quality=85&w=376)
If you want wireless radio that runs on free energy and is disguised as a large pizza, John Greenlee’s “Crystal Radio To Go” build might pique your curiosity—you just need to find scarce supplies like germanium diodes, high-impedance earphones, and Fahnestock clips. You can print or construct a dummy pizza of your preference.
Why build it? Crystal radios are a time-honored beginner’s DIY project. It also has room for growth. Tapping in to free energy is pretty fascinating— you can convert your crystal radio into free energy for other projects. And it looks like a pizza.