Zach in Ala. - 8/30/2008 22:30 dpilot when I was speaking of power lines I was thinking of the transmission lines(the main lines referred to around here as TVA power lines, since they are the regions electric supplier.) These big power lines will cause problems sometimes, particularly when you have a large pond or any other large body of water around. That seems to cause interference with RTK signal sometimes as well. I have not seen where small power lines cause many problems.