Who did so, the USSR? A certain Eastern leader paid Carlos the Jackal to perpetrate a terror attack at Radio Free Europe. Of course that didn't stop shut it down.
USSR did. My dad lived in Belarus during the time (I was born there as well but we moved to the US when I was a kid) and said it was a bit of cat and mouse game re exact wavelength to catch the American radio. Ofc my memory is post soviet and there was no blocking but we still listened to it in the 90s.