One of the most basic tools for tinkering with electronics is a multimeter. Today, even a cheap meter has capabilities that would have been either very expensive or unobtainable back in the 1970s.

You might think the probes in the picture are just funny looking alligator clips. But if you watch [tomtektest’s] recent video, you’ll learn they are really Kelvin probes. Kelvin probes are a special ...