A high voltage interface housing is provided that includes an assembly of levers within the housing that detect whether or not the HV lines are coupled to the interface housing. Specifically, the ultrasonic waveguides comprises a first material having a higher acoustic impedance and a second material having a lower acoustic impedance. In another aspect of the invention, an inverse version of the AM portion of the desired transmit signal is introduced into the power control feedback loop of an amplifier that is amplifying both a phase modulated signal and an amplitude modulated signal.