David - I agree with your comments. By better frequency response, I meant narrower bandwidth and steeper skirts. Not Hi-Fi. :^) I agree with your comments. I think that most SSB operators would be quite pleased with the addition of an automatic notch filter either outboard or internal. - Dr. Megacycle KK6MC/5 ______________________ James R. Duffey KK6MC/5 Cedar Crest NM 87009 DM65