When is the speed of light not the speed of light? Of course, that’s a trick question. The speed of light may be constant, but just as sound travels at different speeds in different media, electronic signals move through transmission lines at a reduced speed. When you have a known cable, you can look up the velocity factor and use it to approximate the length of cable to have a given effective length. But what if you don’t know what kind of cable you have? [More Than Electronics] used a scope to measure it. You can see what he did in the video below.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/04/19/measuring-an-unknown-velocity-factor/