RE: odd results working at 250ksp/s

But his original problem is not with saturated preamps or ADC ... it's aliasing ... and that can be solved in the digital domain provided fast enough ADC.

Yep - if this really is the problem. Aliasing-alike effects also often come from nonlinearities in the overdriven input stages...BTST, GTTS :) The RTL2832 shows this all the time, copies of strong signals show up in expected (from aliasing, proven by simply doing the maths) and not-so-expected areas of the spectrum.

Cheers,

Sylvain

Ralph.