Quote:

The needle is moved through its range by a permanent magnet pushing it up the scale and a fixed/regulated amount of resistance to hold it steady, the faster the internals are spun, the more the magnet over comes the resistance. Must be hard to calibrate them consistently on a mass production scale? I guess if you need/want an exact speed reading, get an Acewell.

Thanks for the technical info. I had no idea.

Fidelis et Fortis