the 475A was basically the same as the 475, but adjusted for higher bandwidth but perhaps slightly inferior pulse response
I'm not sure I understand what you are saying here: wouldn't "inferior pulse response" mean a longer rise time? Wouldn't a longer rise time necessarily mean a lower bandwidth?
I don't really understand all the math, but my impression, from evaluating my father's 475 and probes a couple months ago, was that you calculated bandwidth as the inverse of rise time multiplied by a constant (0.3-something?). Am I misunderstanding what is meant by "pulse response"?
