----- Original Message ----- From: "Jose HF Silva" <zehelmer at yahoo.com> To: <amradio at mailman.qth.net> Sent: Sunday, April 09, 2006 7:21 PM Subject: [AMRadio] Re: AM filter for an SB-300 > What about DSP or SDR? The front end IF Filter establishes the overall bandwidth, the DSP would Narrow that down after the first filter.. Mike