On 11/14/2010 4:23 PM, Bill W4ZV wrote: > I don't know if you've used the K3's APF yet but it definitely needs very > careful tuning to work right (i.e. within 5 Hz of a signal peak...and most > callers don't zero beat me that closely). YES! That's exactly what I'm talking about with respect to it being difficult for contest operation. Jim