On 21 Jan, 22:25, John Rumm wrote:
I have no problem believing that TV detection equipment exists. I do
have difficulty believing it takes a van load of gear to do it though!
Hand held apparatus perhaps.

The link that was given here previously reveals quite a lot about the
different modes of operation of the vans and the hand-held detectors:

http://www.bbctvlicence.com/Detector%20vans.htm

I suspect, but don't quote me on this, that the hand-held detectors
were developed for use with the older generation of detector vans
which couldn't pin down the location of a TV that precisely from a
distance. The current vans can identify the property in which a TV is
in use (e.g. an individual dwelling within a block of flats) from - it
says at that link - up to 60m away. With that capability I don't
really know why hand-held detectors are used at all (maybe they aren't
any more).

Richard.
http://www.rtrussell.co.uk/