BTW I used a oscilloscope in the USAF eons ago then later when taking a electronics class. Surprised at the size and price drop of the new ones, I purchased a DSO Note II LED DS202 scope and with an additional 1x - 10X probe. All for less than $115. Surprised at the quality, I have yet to use it on a real machine, but it can capture and hold signals. Lot of fun re-learning something I last used in the 1970's.
Thought it would be handy to have when checking out the waveform from the VFD and noise on the input signal lines.
So far I have figured out how to display a waveform but not how to Calibrate the grid or the trace?