On Wed, 18 Aug 2004 13:28:20 GMT, Doug Smith W9WI
wrote:

IF shift allows continuous adjustment of the passband, rather than just
selecting upper or lower. You could knock down interference 2KHz below
the desired station without deleting the entire lower sideband. Or,
while monitoring a SSB station.

Could you knock out the 2KHz interference with a notch filter as well?