Turntable Speed Using Strobe 33.3

I have an Amertac Model 73068 that I got at Home Depot. It's a fluorescent nightlight that was on sale for about 4 dollars. It plugs directly into the wall. I use an extension cord so that I can get it up to the turntable. When the dots remain stationary, the turntable is exactly right.

I used to have one that looked like an AC electric power
test light. They might still sell AC power test lights
with a pair of test leads for checking if an outlet has 120
volts AC power.Test light $3-6 or so with a real dim amber colored glow.It might work(the dim "neon"testlight)shinning on your disc.I also see strobe lights with discs on the internet for sale for $25. I just searched "turntable strobe light" There might be better prices?

I use a fluorescent portable shop light which is also handy for other jobs, just a tube with a cord and hooks to hang it and off- on switch.

You don't need a special light. The secret is to use a bulb that is not coated so that the filament is exposed. Just plug it into ac and you should be good to go.

If you can't get a reading that makes any sense with a
fluorescent lamp,it may have a electronic ballast that
is way off of frequency.They are used in a lot of modern
lamps for different reasons.Sometimes to change flicker
rate to cut down fatigue,plus interference problems.The
power companies usually give a fairly steady 60 cycles,
but not voltage.

The frequency of line voltage is almost perfectly controlled: it has to be so as to keep all the generators linked up on the grid in sync. Each day, around midnight, there is a brief time when frequency is adjusted so as to get the number of complete cycles in the day correct. This is done because many timers (clocks) rely on the power frequency for accuracy.

Ordinary fluorescent lights try to minimize flicker, and won't work as well as a simple neon bulb, as in the circuit testers mentioned above.

I'd like to give a "shout out" to everyone who responded and provided vital and important information. This is part of my learning process and I do appreciate. Thanks much all.

Bob