Measuring Turntable Platter Speed

I know exactly how the RR works, Mijo. If the phenomenon that the OP is sensing lasts for less than one full rotation of the platter, I doubt he’d hear it, and the other devices mentioned would be even less likely to detect it.

Anyway, the RR is too expensive for this investigation.  No harm in trying the cheaper alternatives, but the ears tell the story here.

I had a long-delayed second thought. The best course of action, IMO, would be to follow the procedures suggested by MC and oldhvy, and determine whether there is a change in the condition. There are also obvious things, like observing the platter in operation to determine whether it is rotating eccentrically or off axis, either of which would suggest a major problem with the bearing and/or spindle shaft.  I wouldn't be so obsessed with measuring what one can already hear to be a problem.

IF you don't have the feel you can use a stethoscope and listen for the noise on the spindle pocket. You'll hear if something is wrong.. If you know what your feeling for you can just use your hands. Just have to pay attention..

Regards

The short answer is . . no!

But that doesn’t mean you’re at the end of the road. While you can’t measure the fluctuation, you can probably fix it. New bearing, new bearing lubrication, repair of worn bearing, new belt, new motor. Somewhere in there is your answer. A belt driven TT is really a very simple thing. Is there support for this sort of thing at Rega? Is there a forum of Rega users where you might find good advice?

Sorry, but how will measuring help? Won't. All it will do is quantify and confirm what you already know. If the wow seems related to platter rotation that points towards the bearing. Which you would want to clean and lube anyway as that is the next logical thing after the belt, which you already did.

If when changing the belt you also cleaned it and everything it touches with alcohol, that eliminates the belt.

We are now down to the motor. Look closely, is it perfectly straight or bent at all? Listen close, is there any sound with the same pattern as the wow? Can you lube the motor at all? Use only the tiniest amount of oil if you can.

My guess is "slight, quick, pitch changes" could be the bearing. It is an older table and could be going dry. Inspect, clean, and lube. I like Liquid Moly 90wt gear oil but you could use anything and Origin Live is the creme de la creme. In any case do all the steps above. Really just smart ongoing tune-up/maintenance. Can't hurt.