in one aspect , the present invention comprises a method for tuning a power line communication inductive signal coupling device comprising a coupler and a plurality of capacitors , the method comprising : passing a carrier frequency signal through the coupler ; sensing an amplitude of the signal ; and switching the capacitors until the amplitude of the signal reaches a maximum . in various embodiments : the signal is transmitted by a second transmitter , and the method further comprises switching to a first transmitter for data transmission ; the signal is received by a receiver after passing through the coupler ; and the capacitors are switched by a relay controller receiving commands from a microprocessor .