[Elecraft] APF For K3

[Jim Brown]

On 10/25/2010 12:29 PM, Merv Schweigert wrote:
> but never found them useful for CW.  The filter in my head always seems better at picking out the desired signal than the audio filter

That's usually been my experience too, primarily because the skirts ring 
on QRN, and the narrower the filter, the closer those skirts get to the 
CW note.  The closer the ringing is to the CW note, the harder it is for 
the ear/brain to separate them.  This is pretty well known by scientists 
working in the psychoacoustic world.

73, Jim K9YC