[Elecraft] K3 Beta Release: APF for CW/Noise Gate

[Paul Christensen]

> I agree. The K3's APF just blows away the APF on both  the IC7600 and 
> IC7700. The K3s APF is in a league of its own.
Icom doesn't use a peaking filter.  Their implementation of APF is really an 
"Audio Passband filter," rather than an "Audio Peaking Filter."   When 
engaged, their APF filter skirt is really no different than selecting a 
narrow DSP setting where there's a flat top and sharp skirts.  The response 
curve does not resemble that of an audio peaking filter.  I found the APF to 
be of limited value on the 7800 and 7700 transceivers.

Paul, W9AC