This is the timing track waveform from the oscilloscope. A couple dropouts are noticeable. The two near zero spots aren't dropouts. They are the gap at the start of the track. The capture is more than a single rotation of the platter so the same gap is seen twice.
Feel free to contact me, David Gesswein firstname.lastname@example.org with any questions, comments on the web site, or if you have related equipment, documentation, software etc. you are willing to part with. I am interested in anything PDP-8 related, computers, peripherals used with them, DEC or third party, or documentation.
PDP-8 Home Page  PDP-8 Site Map  PDP-8 Site Search