The information in this Power Point presentation was provided to the IEEE C63 “RFI” standards committee at its November 12 – 14 meeting in Rockville, MD. The presenter was Ed Hare, W1RFI, the ARRL Laboratory Manager. ARRL has used EZNEC to model simple power-line wiring to estimate its performance as an antenna, then used the power levels specified in typical PLC industry standards or specifications to estimate the field strength that will result from PLC operation. ARRL has calculated received noise levels of up to S9+30 dB and increases of noise above ambient of 70 dB or more.  PLC will almost certainly cause widespread harmful interference to amateur radio.