Charlie Bohart
Web
project for
Physics 212 Spring 2007
As
a kid I had a Radio shack kit with plans for an "invisible powered
radio," and I built one that worked. I have designed this page
to
answer some of the questions, which I could not answer in
elementary school, questions such as, how do radio waves become
sound? 
Web project for Physics 212 Spring 2007
As
a kid I had a Radio shack kit with plans for an "invisible powered
radio," and I built one that worked. I have designed this page
to
answer some of the questions, which I could not answer in
elementary school, questions such as, how do radio waves become
sound?
I found more information than I could cover in the parameters of this project. Radio waves propagate on to an antenna inducing an alternating current. This current resonates if the antenna is a harmonic (1/n) fraction of the wave length (i.e. 1/2, 1/4, ...1/8, ...1/100). The antenna is tuned with length and/or capacitance. More capacitance, the larger the electric field, the longer the wave length to resonate. The resonate AC current is detected with a diode, cut in half and broadcast as sound though an piezoelectric earphone. The electrical energy from the radio waves rests at ground state. Please follow the links if you need more in depth answers.
