1. Tuning method for a combiner filter ( 2 ) in an antenna near system for base station equipment, the combiner filter being connected to a radio transmitter and being intended to have a centre frequency tuned to the carrier frequency of the radio transmitter, whereby transmitted signals related to the combiner filter are compared with each other, characterized by performing a spectral density analysis of each of the transmitted signals; comparing the spectral density analysis results regarding magnitudes and/or phases of the signals; tuning the combiner filter ( 2 ) based on the spectral density analysis in an iteration procedure until the combiner filter is tuned according to predetermined conditions.