Hugh Riddle
- Joined Jun 12, 2020
- 78
That's fascinating, Dodgydave, and makes sense. Mains cables often carry a lot of common-mode (i.e. acting as a single conductor) HF voltage and current noise, respectively creating HF electric and magnetic fields (a friend had a problem with it interfering with a magnetic deaf-aid loop system) and the AM radio's ferrite antenna must be picking up that HF magnetic noise field. I imagine you need to tune off any station and wonder from how far away it can detect a mains cable. I don't think it could be used for a consumer cable detector but, amazingly, it relies on the same basic principle as the expensive (last resort) cable detector I described. Anyone else tried it? Not sure I've got an AM radio to try it out on.You can use a cheap AM radio with a Ferrite rod to detect electric cables that are live.