>>  Are there certain models that are notriously high quality?

>Tektronix!  Just excellent!

Or Hewlett Packard/Agilent. Either Tek or HP are really the best when it
comes to 'scopes.

The biggest problem you will have with trying to look at serial transmission
(I2C, SPI, RS232) with an analogue scope is that it is hard to "read" the
data unless you have a reliable trigger point and a repetitive wave form
(identical data going across each time). This is where the digital scope
scores because you can do single shot displays. If it is more a case of
looking for marginal levels, then an analogue unit will be OK.

However there is always the possibility of building a digital storage unit
to use with an analogue scope if you need to look at serial data. This may
be useful as you can then set the amount of storage available :)

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