My MFJ 4125 is quite! No noise. I tried it in a motel room with a piece of wire on the floor for an antenna and heard some hash, but I'm not sure it was from the ps. Here at home with a 80/40 dipole and a triband beam NO noise. 73, Kurt W7QHD (since 1951) web page: http://W7QHD.tripod.com