Oh, yes indeed! A potato can and has functioned as an antenna. In high school in the early 1970s I drove a 1963 Pontiac Grand Prix (white, with red interior). Someone broke off the antenna, leaving only a four or five inch stub. (Remember: I’m in high school, and this 1963 car has no tape player. Disaster!) A fellow student–I no longer recall who–insisted a potato stuck on the stub would pick up radio signal. It worked very, very well. Decorative, too. And as the potato got older it loosened on the stub and would twirl drunkenly around when the car cornered.