At wits' end with radio through the speakers!

The ferrite rings might help. Let us know. Short of moving to West Virginia, you might try enclosing your phono stage in a sort of faraday box. It’s impractical to do a true faraday box, but you might encase it in shielding as much as that is possible without hindering your access.

I have noticed after purchasing a Manley Chinook SE MK2 I am hearing  radio stations. However, it is only coming through when the tonearm is sitting on the tonearm rest. Once I lift it up it stops. 

In addition, like the original post my previous phono preamps did not experience this interference either. 

I had a LIO DHT and was hearing radio stations when the amp was turned on. I added a ferrite ring to the the speaker cable close to the amp and the problem went away. 

I bought them on Amazon for $8. 

I had radio pickup when I bought a Naim Superline phonostage, mostly in Russian. A 1nf loading plug (in parallel with the resistive load) reduced the level to where I could live with it but I could never eliminate it until I swapped out the steel framed rack for one made largely of wood, I can only hypothesise that the old rack was acting like an aerial element and focusing the signal but I’d tried earthing it to no avail.