[ibmthrowaway218]

AIUI (from distant days working at BT) the thing they were looking for was the EMR of the CRT flyback transformer. But it could only be detected if the television was towards the front of the house (not behind too many internal walls) and only on the ground floor.

That method has got no hope of detecting a modern LCD/OLED/Plasma display.

The majority of enforcement is database driven:-

Royal Mail database of addresses - addresses of current tv licenses = huge list of possible offenders

Now cross check database of possible offenders with databases of: * Sky or Virgin Media subscribers * people who have recently purchased or rented appropriate equipment (televisions, VCRs, PVRs, etc) * etc

[dominicgs]

Would it be possible to detect the transformer noise in the antenna cable? The cable often runs on the outside of buildings, especially older ones.

I thought that they were looking for the IF (intermediate frequency) being fed back up the antenna cable, but I have no source for that information other than "something my dad once said".

In reality, I'm sure it's like road tax, they check the database of addresses without one against a list of people who own a television. I believe all retailers are required to take a name and address when selling televisions.