Is there any software available to filter signal from sound card and then output it from the same card? I'm using sound from amateur radio receiver, would like to filter out some noise that comes from the air, hunting for the weak signals. Till now I was using stand-alone Autek-Research QF-1a SSB/CW/AM filter, but there should be some software specifically designed for that. I tried Linrad, but couldnt setup it, and it looks too complicated for such simple tasks.