Throughout the 70's and 80's we were all warned that TV Licensing detector vans could locate TV's being used in a house that had no TV licence. An old Transit or Commer van with a metal radar device on the roof, was shown stealthily driving around the streets, homing in on unsuspecting miscreants.
Did they really have the technology in the 70's to home in on one TV signal in a street-full of TV's? In the back of a van? !! ?
So was it just a hoax to make you pay up?
They could detect it back then yes, but like you suggest it took a van to carry around the equipment, these days it can be done with a hand held device.
I don't agree with WoWo I think it's a load of .**.**. Even today the only true way that they can tell if you have tv license is the fact that your address either is registered or not, they can also tell by the fact you may have an ariel on your roof, which can a bit of a give away.
even as a child i knew it was just a scaremongering tactic employed by the bbc to make vulnerable elderly people part with their meagre pensions cos they were so afraid of goin to prison.
The intermediate frequency of a tv gives off a faint radio signal that can be picked up with fairly simple equipment. The main reason the equipment was large was to amplify and pinpoint the position of the signal. Yes, they did work, but I think it was the scare tactics that were the main factor as it would have been too expensive to send these vans around every single unlicensed home.
The technology they had and still use is a directional microphone which they pointed at the vulnerable parts of a house. IE The window, they would then tune into TVs in the back of the van to see if the sound matched the picture to tell what channel you are watching. The same is done with hand hand directional microphones and Tvs in blocks of flats.
Apparantly there are only 8 Detector Vans at work in the whole of the UK...
TV licence avoidance is now checked from a database of addresses which have or have had a TV. And They just send you a letter.
A friend of mine doesn't own a television and hasn't done for the past twelve years yet the licensing people still write letters to him telling him they are aware that he doesn't have a license...you would have thunk they would also be aware by now that he doesn't have a tv either...
http://www.tvlicensing.biz/
Try this site for good information. Also, when you buy a telly now they insist on taking your address (most shops won't let you out of the door with the telly unless you comply). This, to me, is real bully boy tactics.
I remember seeing a tv detector only once in the 1980's around my street one of those commerdore vans white with large tv in blue written on the side.
in the early 90's tv licensing were at a local fair giving away mugs and stuff of whict i have three.