Tremendous RF problem -- phono stage is a radio

I live in an area prone to RF interference, and I had problems with my previous preamp, a Copland tube model. It picked up taxi radios, among other things. When I switched to a Klyne SK-5a, the problem went away. It could have been the Copland's design, or it could have been the tubes.

The first place to look, if my experience is anything to go by, is cabling. Sometimes moving your phono cables, orienting them differently, will solve an RF problem. If you haven't done so already, make sure that if they cross AC wires, they do it at right angles.

If that doesn't help, your phono stage or amp may need better RF isolation, or you may have a tube that is particularly sensitive to RF. Also check your AC line for proper grounding. To isolate from RF, you can cage the amp with wire or a metal box, and ground the cage.

Let us know what you discover, if you get the chance.