Try the Absolute Beginner’s Guide to DSOs by [Arthur Pini] [Pini’s] Cliff’s Notes version of your scope’s manual isn’t half bad. It covers the basic user interface and usage of a ...

This isn’t easy to catch with a level trigger. After all, if you set the trigger level to 3 V, the normal pulses will trigger the scope, too. That’s where the runt pulse trigger comes in handy.