I am an electronics technician, and I work on various types of electronic equipment including radio communications devices which is the reason for asking this question. I was recently troubleshooting a radio communications malfunction, basically when squelch was broken, there was a “noise” (like the sound of frying eggs in the background). After troubleshooting for awhile a fellow technician noticed the trouble seemed to affect our truck radio the closer we got to the power transformer feeding the communications facility. We called the local power company and as soon as the electric company technician got close to the transformer he said it was definitely bad. He explained there was a “gap” of some sort that needed to be maintained, if not, the transformer would arc and cause radio frequency interference. I did not understand what he meant by this but, at the time we were glad to have the issue resolved. Since the issue I have asked several technicians and polled the all knowing “Google” I keep hearing the same sort of answers like “arcs encompass all frequencies, thats why arc welders cause RFI”, I am still unclear exactly what is happening to cause the interference. When someone says “arcing encompasses all frequencies” are they implying that when current flows from the electrode of a welding rod to the metal that there is a wave of electromagnetic energy released that encompasses all frequencies? If that is what they are implying is it correct? If it is correct how can it encompass all frequencies? I am sure there must be a basic concept I am missing, but thank you for your time in helping me to understand this.