No subject

it was a saturation issue in RF, it would show up no matter what the
sample rate is.

Also :
 - RF filter are often only band specific and not channel specific
(because tunable RF filters to do channel selection would be
prohibitively expensive)
 - IF filter (or BB filters for zero-if) are then used for channel selection.

So in his case being two channel in the same band (and given the
architecture of the dongles), the only saturation that IF filters
would provide would be against ADC saturation and it's easy to check
if this happens or not just looking at the time domain signal.

Cheers,

    Sylvain