Hand Crank Radio into Perpetual Motion Machine?

I was just day dreaming about these devices earlier today. And I was wondering if it were possible to have the power source that powers the radio power the crank instead. So you would just have to crank it a little while and it would power itself. I guess something gets lost in the action of cranking the radio or maybe the power generating part so it won't actually be perpetual. It sure would be cool though to crank a radio for a while then the radios crank slowly turns on its own powering the radio after that. I need to e-mail a physicist to see if this is actually possible.