Jonathan Brown is at the Combined Military Services Museum in Essex, where he talks about one of their military artefacts, a covert operations listening rig from the 1970s, used by British forces in Northern Ireland to listen in on conversations which could hold valuable military intelligence.
Access to the listening rig, courtesy of the Combined Military Services Museum- link to them is below.
https://cmsm.co.uk/
Link to YouTube video of the listening rig:
https://www.youtube.com/watch?v=ZA46FrTMjcs

Music: Cinematic Dramatic Tense by Lexin Music from Pixabay.