A coupling circuit for power line communications includes a coupling transformer having first and second mutually coupled windings, with the first winding connectable to a power line. The second winding includes a pair of intermediate taps with one or more tuning inductor therebetween. The inductor or inductors are set between a first portion and a second portion of the second winding of the coupling transformer. A switch member is provided coupled with the inductor. The switch member is selectively actuatable to short-circuit the inductor.