I believe that the frequency actually is deliberately managed... to keep old clocks synced. https://www.kccscientific.com/the-dirty-little-secret-about-mains-p

I believe that the frequency actually is deliberately managed... to keep old clocks synced. https://www.kccscientific.com/the-dirty-little-secret-about-mains-power-line-frequency/ https://www.kccscientific.com/the-dirty-little-secret-about-...