Tuning a programmable power line filter, the power line filter including a live line, a neutral line, and a ground line connected to input terminals of the filter on an input side of the filter, the live line and the neutral line connected through inductors in the filter to output terminals on an output side of the filter, X-capacitors selectably connected through tuning switches between the live line and the neutral line, Y-capacitors selectably connected through tuning switches between the live line and ground and/or between the neutral line and ground, and a tuning control circuit connected to the tuning switches and selectably connected through one or more programming switches to the load, including measuring by the tuning control circuit the input impedance of the load and programming by the tuning control circuit the tuning switches in dependence upon the input impedance of the load.