Eric R Snow wrote:

Why might I be eletrocuted by plugging in the scope to the mains and
then touching the probe to the hot lead from the AC generator?

First:
Because probes normaly only have an isolation voltage of 400V. I already
hear your answer. But it is wrong.

Second:
You have to connect the probes GND somewhere. And this is where your
problems start.

Your question is OT here. It doesn't matter that much, because there is
more OT than OT (on-topic) here. But in your case, it matters. You might
get stupid answers. So please ask in an electronics group. They will
tell you solutions that are quite save.

BTW:
Don Foreman gave you a save answer.


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige