I thought the same thing ejs
I tried a microfilter but still got the interference. There's no DSL on the line so I wondered whether the microfilter, being passive, needed an active DSL service to work. As such, I've also placed an order for a high quality active microfilter (xf-1e) (which contains a transistor based ciruit powered by the line) in order to try again and see whether that will filter out the AM radio station (which incidently is GOLD on 1548KHz).
Between that and an RF2 I'm hoping one or the other will work, otherwise it's back to the drawing board scratching my head.