The loop voltage of REPUTE-1 RFP is decreased by reducing the toroidal field ripple. The low frequency part of the toroidal field fluctuations, which is mainly composed of the m = 1 mode and has good coherence in space and time, is found to be reduced, especially outside the reversal surface, when a trimming field is applied. High frequency fluctuations, which have little coherence, are not influenced effectively.