The Duchess of Edinburgh made an unexpected cameo appearance on the BBC Radio 4 staple, The Archers.A self-professed fan for many years, Sophie joined the fictional residents of Ambridge in Thursday’s episode.Her segment was secretly recorded in May at the BBC Mailbox in Birmingham. Behind-the-scenes photographs showed the Duchess smiling as she stood before her script and microphone under the studio lights. She was joined by actors Tim Bentinck (David Archer), David Troughton (Tony Archer), and Susie Riddell (Tracy Horrobin).The episode, broadcast at 7pm during the drama’s 75th anniversary year, featured Sophie as a surprise guest at the fictional Borchester Show, appearing in her real-life capacity as honorary president of Linking Environment and Farming (Leaf).“Nerves are frayed on the