This spinner is very similar to spinners that step with the AC line frequency. The big difference is that a relaxation oscillator (using a simple NE-2 neon bulb) is used to step the dekatron. This type of oscillator's frequency is adjustable, which means this spinner's spin rate is not dependent on line frequency. I this case a simple trimpot (as part of the RC network) is used to vary the step rate.
