It seems as though every electrical device has the potential for rf. Keep in mind rf is simply unwanted radio wave (magnetic field) interference. For instance, most magnetic fields that are present in your home do not interfere with other electrical devices. The ones that do are refered to as rf. In the case of a HAM radio, I would be more concerned with rf from local external sources such as high voltage overhead power lines or substations. When the overhead power lines are run in a phase configuration (where all 3 phase conductors are grouped together)and proper grounding is in place, the rf is greatly reduced.
The key to eliminating or reducing rf as far as electricians are concerned, relates to good wire connections and whenever possible, installing conductors in metal raceways with proper grounding. Beyond that, one would have to be careful as to the quality and proximity of other electrical devices.
I think if I were wiring the home, I would recommend that the home owner stay away from all ballasted devices and device that utilize transformers.
Remember, rf is a radio signal. It is more important to eliminate the unintentional antenna (metal frames on windows, copper water pipes)that may exist in the vicinity of the HAM tower and radio!
Sorry, didn't mean to blabber on!