I live across the street from the phone company and three blocks from a major AM radio station. I live in an apartment house with all sorts of crazy wiring in it. When I got into vinyl, I had serious hum and RF noise. I tried everything: RF stoppers: didn't work; power conditioners: didn't work; cheater plugs: didn't work. Then, on a whim, I borrowed a Linn Linto phono stage from a local dealer and all the hum and RFI immediately and completely disappeared.
I don't recall the details, but there is something unique about the way Linn designed the power supply which makes it impervious to EM and RF noise. I went and bought the Linto and have never heard a bit of RF or EM noise since.
It's a bit pricey, but, for me, it was the only thing that allowed me to enjoy vinyl. You can find one on a'gon for about $800 used.
Good luck!
I don't recall the details, but there is something unique about the way Linn designed the power supply which makes it impervious to EM and RF noise. I went and bought the Linto and have never heard a bit of RF or EM noise since.
It's a bit pricey, but, for me, it was the only thing that allowed me to enjoy vinyl. You can find one on a'gon for about $800 used.
Good luck!