Measure My Turntable Speed

Given the relatively slow speed of a turntable, it may be difficult / expensive to find a tach that measures with enough resolution to give accurate readings. An alternative approach is to either buy or build a counter and measure the number of revolutions over a fixed, measured time - there are as many ways to do this as you can think of. Perusal of catalogs from companies like allied electronics will likely lead to an optical counter. If you can let the unit run for a measured extended time you will end up with an accurate average of the speed of the turntable. While this is a different measurement than the instantaneous result from a tach reading it is not necessarily a less informative result. Multiple tach readings and average readings would tell you more about the speed and stability of the unit. My guess is a little research will yield an inexpensive counter or the components to build one.

Just use a very cheap strobe disc and a flourescent bulb light source. The bulb flickers at a rate related to the 60Hz regulated frequency of the powerline. Even an incandescent bulb does this and can be used (though the image is not as clear). The frequency is so very close, any irregularity would be inconsequential.

Personally, I don't get it. A Kab is relatively inexpensive yet most of you want to rally around a light and cardboard. Go for it .

I don't get it either. Why measure unless the needle is in the groove?

A paper disc and fluorescent light are all that's required.

You don't need the overpriced KAB toy. That's quite simple.

Get it?