Need to adjust the speed every time I turn on turntable

AC synchronous motors rely on stability of AC frequency, which before accounting for noise from other sources can vary by up to +/-2Hz, which is an error range of 6.7%. Noise that breaks the synchronization can increase this to 10% depending on the power factor of the source. Bottom line is to use a line frequency conditioning device for equipment that has AC synchronous motors. This is why quartz oscillator disciplined phase locked loop controlled DC motors maintain speed with much greater precision and reliability. 

sleepwalker65

AC frequency, which before accounting for noise from other sources can vary by up to +/-2Hz ...

Please explain how noise affects AC frequency and how you arrived at this spec.

Noise that breaks the synchronization can increase this to 10% depending on the power factor of the source.

If that were true, the entire connected electric grid would collapse. The function of the AC frequency is to allow multiple electric sources to be connected and work simultaneously on the same grid.

The grid is constantly adjusted to within 0.5 Hz of 60 Hz. It tries to vary with load. Higher loads tend to slow it down. The number of cycles per day is held to a constant (so clocks will stay on time). Any spurious signals contained on the line would not effect this frequency or the operation of any AC motor. AC is the preferred way of transmitting  electricity to customers because it is way safer, more efficient and lower maintenance than DC. Westinghouse 1, Edison 0.  The grid is protected from local occurrences by transformers, those cans hung up on the poles that reduce the voltage from kilo volts down to 120 per leg. Transmitted power has three legs at 120 degrees. Industrial zones get all three legs and have "three phase power." Residential areas get only two legs which sucks if you like big woodworking machines. You have to get a phase converter and manufacture the third leg. I digress. One fart from cleeds and the whole electrical grid will collapse.  

mijostyn

AC is the preferred way of transmitting electricity to customers because it is way safer, more efficient and lower maintenance than DC.

Oh no, AC is not safer than DC - that was Edison’s argument when he was battling it out over power distribution. That’s why Edison promoted the electric chair. It’s all in the history books.

mijostyn "One fart from cleeds and the whole electrical grid will collapse."

Mijostyn I have mostly thought of cleeds as an oozing infected boil but you're observations about his incessant masturbation and farting raise the question of which is worse hear is it the foul result, consequence, and effect of his farting or is it cleeds spewing of jizz after massaging his little flesh stick that is worse?