I am not an audiologist (?) but isn't a harmonic that is 45db below the fundamental tone essentially non-detectable to normal hearing? Kind of why the harmonics of a RF carrier are to be 40dbs down. Rich -- View this message in context: http://n2.nabble.com/K3-Harmonic-Distortion-tp797780p842449.html Sent from the Elecraft mailing list archive at Nabble.com.