Want to answer an easy crystal radio question?

Question

I read that if you don't connect the ground, the charge will build up. How much charge builds up, at what rate, and what affects the amount that can build up?

Answer 1

I am not sure what this has to do with crystal radios specifically but with any circuit, not grounded the potential for static charge building is great.  If you put up an antenna it's greater.  Think in terms of lightning whcih is a discharge of that static potential.  Grounding a crystal radio properly (or any radio for that matter) will permit the charge to bleed off if done properly and will provide a path to ground for the lightniing strike if it doesn't bleed of fast enough.  Properly is the key word here.  Just as an aside, a crystal radio with an antenna and ground works a lot better than one with only an antenna!