You can’t really detect “TV signals”, but you can quite easily detect the 10.125 kHz horizontal line-scanning deflection coil of a CRT.
Though I’m fairly sure even if they did originally start effective back in the 1950’s because people had very few elecronic devices around, actually detecting anything accurately must have been increasingly difficult as time went on, and a lot of the newer models must have been more about being a scare tactic.
Scare tactics definitely play a part of it but, having seen official documentation covering up to reasonably recently (can say no more, sorry), I can confirm the technology described did exist, continued to evolve beyond that, detection was possible, and the vans were / are real. I’m sure it’s continued to evolve since those old docs too, and I can’t say it was ever particularly effective, but there was some clever stuff at play from what I read!
Of course it’s all in aid of a horribly outdated principle, and I don’t approve of the scare tactics or intimidating nonsense letters, but I can appreciate some clever tech and documentation :)
https://en.wikipedia.org/wiki/TV_detector_van
You can’t really detect “TV signals”, but you can quite easily detect the 10.125 kHz horizontal line-scanning deflection coil of a CRT. Though I’m fairly sure even if they did originally start effective back in the 1950’s because people had very few elecronic devices around, actually detecting anything accurately must have been increasingly difficult as time went on, and a lot of the newer models must have been more about being a scare tactic.
Scare tactics definitely play a part of it but, having seen official documentation covering up to reasonably recently (can say no more, sorry), I can confirm the technology described did exist, continued to evolve beyond that, detection was possible, and the vans were / are real. I’m sure it’s continued to evolve since those old docs too, and I can’t say it was ever particularly effective, but there was some clever stuff at play from what I read!
Of course it’s all in aid of a horribly outdated principle, and I don’t approve of the scare tactics or intimidating nonsense letters, but I can appreciate some clever tech and documentation :)
The German version of that very article says it’s not possible. Now what? w(°ｏ°)w