The K3 (and K3S) have an external ALC input that that an amp can use to ramp power down in the event of serious problems such as a sudden change in antenna conditions. This ALC has an intentionally slow rise time to prevent the kind of splatter most amp-rig
combinations create on the air due to ALC dynamics.
To meet the requirement of staying just below the external ALC threshold:
1. Set menu entry CONFIG:EXT ALC to OFF. Set CONFIG:PWR SET to PER BAND.
2. Adjust the K3's power output on each band such that the amp just hits the desired power level on voice peaks. Once all bands have been set up as described, you should rarely have to touch the K3's output level.
3. Set EXT ALC to ON and adjust the voltage so that the amp's ALC output barely "tickles" the K3's ALC input at peak.
When you want to run the K3 barefoot and have the PWR control set the power the same on all bands, just return PWR SET to the NOR setting.