Strobescope Here is a strobescope that can be used to check that your turntable is running at 45 rpm on a 50hz (i.e. UK) power supply. It is particularly useful if you have converted an American machine to work on British Mains. Instructions for use: Follow the link below to download a zipped up version of the full size windows .bmp strobescope image (saved to print at 300dpi). Print it out onto thick paper or card and then cut out one of the two centre holes. Place it on your turntable and start the motor running. When viewed under an artificial light it will appear to stand still if the motor is running at the correct speed. If the lines appear to move clockwise then the turntable is rotating too fast; If they appear to move anti-clockwise then it is rotating too slowly.