04-10-2019, 11:40 AM
(This post was last modified: 04-10-2019, 11:40 AM by peter scott.)
Don's analysis of the phonovision apparatus is interesting. It appears to show only one universal joint in the connection between the turntable and the scanning disc and Don suggests that the distortion seen on a horizontal line on the recording might be due to a slightly bent shaft but that this was later corrected.
I wonder if there might be another possible explanation. If a universal joint is used with any angle between the input and output then a constant speed input will translate into a non-constant speed output.
The shaft slowing at one sector of its rotation and speeding up at the other sector.
If two shafts are to operate displaced sideways from each other then two universal joints are required and the overall input and output shafts must be on parallel axes. The shaft connecting the two joints will still not run at constant speed but with identical angles for the two joints the input and output will run with identical speeds.
See: http://www.nostalgiatech.co.uk/New%20page%2019.htm
Peter
I wonder if there might be another possible explanation. If a universal joint is used with any angle between the input and output then a constant speed input will translate into a non-constant speed output.
The shaft slowing at one sector of its rotation and speeding up at the other sector.
If two shafts are to operate displaced sideways from each other then two universal joints are required and the overall input and output shafts must be on parallel axes. The shaft connecting the two joints will still not run at constant speed but with identical angles for the two joints the input and output will run with identical speeds.
See: http://www.nostalgiatech.co.uk/New%20page%2019.htm
Peter
