I have some terrible rfi on my radios , I have a Anytone 6666, Uniden 980 and a Cobra 148 GTL , all of them use the same antenna[ 5/8 Sirio 27 Ground plane] up 52' to the top. The noise I think is power line noise from the lines in front of our house. Probably about 200' from my radios. At times it sounds like someone is welding on my desk right in front of me.I call it a welding noise as it buzzes real loud for about 4 sec then off for about 4 sec then back on again.this goes on continous 24/7. I have hooked the radios up to a 12 volt battery and turned the main breaker off in the house which kills everything. The noise still prevails. I live in North East Ohio and I had to contact the PUCO to get the power company to respond to my calls.... That has been a year ago and nothing done yet. I have no businesses near me because i live in a rural setting. I dont know where to go next.