This has been going on intermittently for several days now but as I type this there is a slight 'swishing' distortion on the right channel on BBC Radio 2 from Rowridge. The sound is following the modulation of the signal. I have checked two of my tuners, a Kenwood L-1000T and Denon TU-800L, and the effect is slightly more noticeable on the Kenwood. Is anyone else hearing it? So far Radio 4 has been unaffected.

Sometimes it is Radio 3 that has been affected, and it seems to happen mostly in the late evening, which can be very annoying whilst trying to listen to 'Late Junction', for example.

I contacted the RTIS website when I first noticed it last week but I don't really have much faith in that service. Any ideas of next steps I could take?