Thanks Bob!! Sure wish that link was put here days ago. That solved everyones problem and now we have understanding. 73 john-n4dsp ----- Original Message ----- From: "Bob Cunnings" <bob.cunnings at gmail.com> Subject: Re: [TenTec] Noise Reduction Setting > http://en.wikipedia.org/wiki/Wiener_filter > > is a good description of the system. > >