The station's were on Medium Wave (AM in the U.S.) and at night could be heard in other countries across Europe. AM uses the Ionosphere to bounce off of so the signal can travel farther. This was the reason why listeners were tuned in at night and listen until sunrise.
Sister Boniface has a fantasy element as a DJ where she turns the dial up to 11 in an obvious reference to This is Spinal Tap.
One of the songs played is "Out of Sight" by The Queenmakers, the rock band from series 1.