Helpful. Another thing to notice: You don't necessarily need a pcb. For small demo purposes you could close-pack one layer of serpentine insulated wire, then a

Helpful. Another thing to notice: You don't necessarily need a pcb. For small demo purposes you could close-pack one layer of serpentine insulated wire, then a second layer of a second serpetine wire. There would be a height difference, but perhaps not more than with a two-layer pcb.