"the broadcaster refused to give further details because if it did so it would damage the public's perception of the effectiveness of TV detector vans"

Says it all, really.

They probably dont want the public to know that they can only detect the old CRT tellys and are useless against modern tellys...

that's between me and you, right?

When i moved about 400miles across country i kept getting letters telling me that me old address had a TV "detected" and i would be taken to court - dispite the fact there wasn't even electricity at the old house let alone a tv!

It took dozens of phone calls and the eventually threat of lawyers to get them off my back.

One of our local newspaper journalists wrote about this not so long ago.. basically the whole system seems to revolve around sending threatening letters, which is exceptionally annoying if you don't have a TV. I'm currently selling a property which is empty, and although the TV licensing people have been told this, they STILL send threating letters promising legal action.

Anyway, a link to the story is here: http://www.bedsonsunday.com/bedsonsunday-news/DisplayArticle.asp?ID=260556

I understand that it was straightforward to detect a good old analog TV with a CRT, because all that HT circuitry would ring like a bell and radiate a lot of EMF. I really don't think it would be quite so easy for a van on the street to spot a low-power USB stick tuner plugged into a laptop up on the 4th floor, for example.

Of course, one can write to them by recorded delivery saying "no I do not receive television broadcasts so I do not pass go and do not need to pay £200 (whatever)" They will "remove" you from the database and promptly start chasing "The Occupier" (twisting the DPA no doubt, however...)

Not anonymous because I still don't need a licence

Having worked with people that developed some of the equipment that goes into these vans (although not in the same department) I can tell you that they do work.

They had a test van that just looked like an old camper van and they have been known to park it outside the house of one of the people in the team and tell him the next day what he was watching!

I'm not going to go into details (for the same reason the FOI was denied) but I can tell you two things:

1) They don't work in any of the ways that you are likely to come up with unless you are already in the business

2) They do work pretty well and without some reasonable knowledge of the workings, you probably couldn't prevent them detecting your set

Posted AC because I'm probably not even allowed to say that much!

Back in the good old days, a TV was an analogue tuner and a CRT. Picking either/both of them up from a few yards (we are talking pre-metric) away whilst not exactly trivial, was possible. A TV composed of a LCD and a UHF ADC is a lot harder. Proving that the two components are in fact a working TV is harder still, whereas formerly any CRT in a domestic situation was almost certainly a TV tube.

You have to pay a license fee for over-the-air television??

"After answering part of the request the broadcaster refused to give further details because if it did so it would damage the public's perception of the effectiveness of TV detector vans."

Mainly because they don't do anything. They are nothing more than a fear-inducing device to make you think "shit... they're detecting in my road.. I better do something quick!".

Let me explain the flaw in a TV detection van. The supposed principle is that any piece of reception equipment will re-transmit the signals its received after demodulation. This is true, however the nature of those transmissions is unstable.

The reason you can "tune" any radio device is because the signal is on a carrier frequency. By modulating this carrier (amplitude for vision, frequency for audio) you can encode the information. The point is, the information is always around the carrier frequency in one way or another.

Now, demodulate that signal and you're left with the raw information. The frequency jumps about wildly, the amplitude is unstable, there's practically nothing to lock on to. The best you can hope for is the presence of a sync signal, at a fixed rate of 50Hz for vertical or 15kHz for horizontal. But realistically, these could be anything from background noise to mains hum. You're just not going to be able to accurately deduce the reception of a video signal.

Meanwhile, there's the transmission strength issue. As anybody whose played with a science fair electronic set knows, even with 9V of battery behind it, you don't get more than a few feet unless you have a serious mast handy and a decent power transmitter. The maximum voltage is (or should be) around 1V inside a telly, before its seperated into bits for assembling the picture. This isn't going to transmit more than a few centimetres from the television.

Anything that is higher than this won't be a proper TV signal, and comes under the same heading as background noise.

So, in short, TV detector vans are pretty impossible to work unless televisions have a built-in "find me evading licensing here" beacon. The vans are a scare tactic. The BBC/TV Licensing have a database of all addresses with licence. Anyone who doesn't fit this gets a visit from TVL agents, who think they have police powers. They have in the past turned up at people's houses who have nothing even close to a telly, and told them straight faced "you have a television because we've detected it - now pay your licence fee!".

Oh and of course, if you call your local neighbourhood bobby to resolve the issue, they will take sides with the TVL. I'm afraid the BBC is most definitely on the corrupt organisations list, along with the police, the court system and the government.

-- Richard

..if MythBusters were to pop over to the UK and test this myth out?

It's easy to detect a TV if it's in front of you, it's not so easy if it's in amongst 100 other TVs or up high in a multi-story flat.

Much easier to have a empty van with a fancy looking aerial on it with the words "BBC Detector Van" blazing on the side. Darn sight cheaper too.

Odd that no person has ever posted (not even anonymously?) that they've been in a working detector van. Have they all been sworn to secrecy all these years?

If they really worked and we *knew* that then why would people stop buying a licence?

It's believing that they probably don't work that is gonna encourage folks not too get one i'd say.

I got red lettered by these twats so I phoned them up. I made it quite clear that I don't own a tele and don't intend buying one ever, since I have a projector and 6 foot screen for my xbox and dvd player etc. The lady was very nice and updated 'my account'. The best she could do was a 3-month update, which means that in three months I'll start getting letters again. I hate the way that you have to prove that you don't have a tele - it should be the other way around. And they're so aggressive about it too. "If you don't pay up you face a massive fine and buggery in prison by bigger-boys...." They don't give a flying fook if their information is incorrect.

BTW is there anyway to get your name taken off the BBC's TV license database? If you don't own a TV then why should your name remain on there?

Next time I won't respond to the letters at all. I'll wait until they send someone to the door... I'll open it wearing a mankini and I'll do an Alan Partridge on them - sit down, lift both my legs up so they can see my dinner and cry out "search me search me".

I believe it is quite possible to pick up EM emissions from an old-fashioned CRT set using a directional antenna array, thereby proving its use and location once some triangulation has been done. I think it is even possible to see the picture, as there used to be some security fears over computer screens being read remotely.

But your modern LCD or plasma jobbie is a different beast altogether. I think you'll have a hard time detecting one of those.

Those who campaign against the licence fee usually trot out one of four wobbly arguments:

1) "It's too expensive (but I pay for Sky)"

2) "I never watch BBC (but I pay to watch adverts on Sky)"

3) "We should have a choice over what we pay for (but, in reality, I'm too stupid to make decisions for myself because I prefer paying to watch utter dross followed by adverts on Sky)"

4) "I work for Sky."

So, with apologies to those who genuinely don't have a TV, I much prefer the option of bullying those who would see the end of our venerable, valuable though occasionally flawed BBC and turn British TV into the unwatchable 'experience' like what the Yanks have.

It's about quality over quantity, people.

To say something like "But TVs only RECEIVE - they don't TRANSMIT so TV Detector vans can't possibly work!"

They wouldn't keep pestering people who don't have a TV if they were real

"it would damage the public's perception of the effectiveness of TV detector vans"

That's just saying "there's nothing in then, which we don't want people to know otherwise they won't be worried into paying their licence fee"

Handheld detectors are the clipboards the "enquiry officers" carry and the detector vans are the minibuses they are carried round in. That's what I reckon anyway.

I don't have a TV so I don't have a licence and I keep getting these "enquiry officers" knocking on my door. The licence is enforced like a protection racket; don't pay for one and you get threatening letters and people knocking on the door.

"Requests for authorisations for the use of detection equipment must be made in writing to the Head of Sales and Marketing or anyone holding a more senior role within the TV Licence Management Team of the BBC" .... like the janitor, seriously the guy responsible for authorising requests that fall under RIPA is the S&M guy. That there is blue-pie-in-sky thinking.

"the number of detection devices and how often they are used will change the public’s perception of their effectiveness." .... so there is only one

"the technical elements of the detection devices would leave open the possibility of people analysing them to find weaknesses to evade detection equipment"... and the information we do retrieve is buggy and flawed.

TV licensing's database is simply the PAF so that's flawed too.

Look here Auntie - before making nice little generalised slurs about sites discussing the current licensing arrangements, take a moment to question whether or not you have the balls to actually risk naming one and having a constructive debate. If the answer is no, then sod off...

In this instance though, I'll save you the trouble... You're referring to www.tvlicensing.biz - the only major site with user participation on the topic. Yes, there are some people on there discussing evasion - but there are also a good many people who whilst remaining within the law, discuss the failings in the current arrangments. I'm used to be in the latter category, and resent your implication that I might be in the former...

Repeats have gotten so numerous in our schedules now that I think there is ample scope for a discussion as to whether Auntie is fit to be left holding the baby...

Martin.

(Muppetman from the site, though I don't pretend to speak on their behalf...)

Anyone ever seen a van? Anyone ever had a vist from the 'enforcers'? If yuo have, let this guy know .http://www.bbctvlicence.com/index.htm

It's not exactly rocket science. Television receivers are superhets (and therefore contain a local oscillator). Some of the LO signal couples into the antenna cable. Television antennas are highly directional, and have just enough bandwidth to transmit at the LO frequency.

Now, if the detector van's receiver was a superhet -- and, since this is the most sensitive kind of receiver, it's unlikely to be anything else -- then you could theoretically build a TV detector van detector, which would cut off the power to your TV when it detected the detector van's own local oscillator! But in order to do this, you would need to know the intermediate frequency used by the detector van's receiver, in order to work out the local oscillator frequency that you were looking for.

What I want to know is, WHY did the Government not mandate card readers on ALL digital receivers from the beginning of the switchover? Then the BBC could have broadcast their programmes scrambled, and anyone without a viewing card would also be without pictures. That would surely have been the fairest way to do it. It's inconceivable that nobody from the industry would have mentioned this possibility during the initial consultation, so on what grounds was it blocked?

I can confirm the existence of them - after TV Licensing sent me my licence (paid for by direct debit) and in the same post a letter telling me that I needed a licence or I'd have to pay a fine, I ignored the letter (there was no free way to contact them - their error not mine, why would I want to pay to tell them their database is rubbish) - a chap duly turned up in a spinning roofrack mobile.

He insinuated that he had the right of entry (he doesn't) and harrassed my other/better half for over an hour. Eventually I came home, told him to clear off and to make an appointment with me by letter. At no point had he asked to see the licence, so it wasn't shown to him.

He did go away and I got an appointment alright - at the magistrates court.

Defending myself, and taking along the last 15 years worth of TV licences and bank statements showing I was still paying - I predictably won the case (and costs), remarking "if it's all in the database, then clearly the database is rubbish" - much to the amusement of the bench.

Probably want to hide that they only have 2 vans and 6 employees in the 'fleet', and the rest funds the BBC black ops projects.

of course in the old days they had a 1in 4 chance of guessing the correct channel so saying they can tell what you were watching isn't much.

I wonder if tinfoil wallpaper (a househat) would prevent detection??