The alfa motor controller is inside a huffman box. There a few cables that come out to the motor as well as the ac power line. ... The box was using a corcom 6EF2F power line filter. A preliminary sweep of this filter from 0 to 2 ghz using a synthesize and spectrum analyzer showed that the filter worked well up to about 200 MHz. ... We need to figure a way to improve these filters since many of the devices in the huffman boxes have computers that are running at multiple ghz frequencies. ...