> You're talking about aliasing problems.
> I'm not sure what you mean. These scopes have a sample rate of 1 GS/s and
> an analog bandwidth of 100 MHz (60 MHz for the TDS 210).
>
> Aliasing should not occur with frequencies less than 500 MHz.
> Since the bandwith limitation would attenuate such a signal to
> virtually zero, I cannot see how you would be able to experience
> aliasing problems.
>
> Care to explain?

The problem comes when a scope is used on a slower timebase; most digital
scopes, if they have 20 pixels/division, will sample at a rate of only
2MHz if set for 10us/div; at 1ms/div they'll only sample at 20KHz.

This behavior makes it very difficult to use such scopes for looking at
certain types of signals; if I'm looking for short pulses widely spaced,
the scope may not see them AT ALL if it's not set for peak-detect mode.
If it IS set for peak-detect mode, then it may be highly succeptible to
noise pickup.