The Ferris State University Carrier Cuurent Station, WRKX, was given an old WSAM 250 watt transmitter as a donation around 1979. They split the signal and ran transmission lines to all the dormitories, where they were matched to a carrier current power line antenna. This avoided the heterodyning between the old individual transmitters in each dormitory. It met Part 15. Some of the old transmitters had second harmonics that got out much further. That was most likely not Part 15 Compliant.