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Old 26th Nov 2014, 2:40 pm   #9
richrussell
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Join Date: Jul 2008
Location: Selby, North Yorkshire, UK.
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Default Re: Why were the rpm speeds of records chosen

Quote:
Originally Posted by Radio Wrangler View Post
I wonder if 78rpm happens to have realisable gear ratios to both?
Yes indeed, for 60Hz a 46:1 ratio gives 78.26rpm, for 50Hz a 77:2 ratio gives 77.92rpm. That's certainly close enough.
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