- Harry: "Maybe she had you bugged..."
- Hermione: "All those substitutes for magic Muggles use - electricity, computers, and radar, and all those things - they all go haywire around Hogwarts, there's too much magic in the air. No, Rita's using magic to eavesdrop, she must be... If I could just find out what it is…ooh, if it's illegal, I'll have her..."
- — Hermione contemplates revenge on Rita Skeeter.[src]
Radar, along with electricity and computers, was cited by Hermione Granger as an example of Muggle technology that did not work in the vicinity of Hogwarts School of Witchcraft and Wizardry due to magical interference.
- Harry Potter and the Goblet of Fire (First mentioned)