  Ingraham, Andrew ( Thu, 20 May 1999 17:18:58 -0400  >Based
upon that general scenerio, what bandwidth scope should be
adequate >for doing SI analysis on our board?  Sometimes you can
never get enough bandwidth.  > We are currently looking at a
scope >with a 1.5GHz bandwidth (8GHz sampling rate).  What is
the bandwidth when probing two signals? Three signals?  Probing
one signal at a time covers about 75% of your SI needs, but you
may also need to check timing between signals.  Consider your
fastest signal risetimes, not frequencies.  What usable
bandwidth do you get when capturing a long trace; what memory
depth does it have? If you use a slower sweep rate, and blow up
a small portion of it to full-screen, you may not get the full
sampling rate.  How about the processor speed of your NEXT
product, and the one after that? You may want to be able to
display its 3rd, 5th, or higher harmonics.