Hi dgebert,
I think that determination of the distance between the anennae is done using either the volume of the signal. or by comparison of the nodes in the field.
Hello, all
The availability of second hand microwave ovens has led to a large group of experimenters with this equipment. (http://amasci.com/weird/microexp.html)
The strange thing is that I was unable to find anything similar for induction plates.
Induction plates may be suited for similar...