[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.