[Closed] Are TV detector vans real?

No.

Scam made up by TV licensing as a threat to get you to pay for a license.

They do have all records of licenses and work on the basis of expired licenses at properties.

IMo

I've had a man at the door of a block if flats to check that i didn't have a tv*.

He was working of a list of people without licences.

*I didn't have a tv hooked up to an aerial which is legit

It would be possible to detect a device which was transmitting radio waves / tv signal through the air. However it would be impossible to detect what was receiving those signals as technically everything is receiving the signal

There used to be a Comma van with a huge horn-like aerial on its roof and "TV Detector Van" written on the side. Amazing that somebody was actually paid to drive it around, striking fear into the hearts of the population at a time when people were beginning to get TV sets. Nowadays they just assume that everybody has a TV.

Currently Lancashire's only motorway Police car is doing the same PR job by cruising up and down the M6 using ANPR to nab idiots who haven't got insurance. Then Lancashire Police tweet aout it to create an impression of a high success rate. Meanwhile in cities like Blackburn it's open season for hotted-up German saloons to race around recreating Grand Theft Auto and deep in the countryside, drink driving is having a revival.

Having worked in a few places which were subject to Tempest testing I'd say detector vans are certainly feasible but I don't think they exist and I couldn't see them being a cost effective means of enforcement compared to a door knocking campaign with even a low success rate.

The technology could potentially have been there, but no they didn't exist other than PR stunts, in an advert, and maybe some "demo" on Blue Peter or Tomorrow's World or something.

Does one really believe that the BBC or licensing authority would have had a fleet of vehicles roughly equivalent to the same effort that Google streetview is doing now, but in the 70's/80's? or the SatNav mapping companies?

At most it was a database of who had a licence, and agents going around to targeted properties to chase up. And big TV/Electricals chain-stores coerced in to forwarding details of TV purchases.

And now there's a display device in every room of practically 100% of households (including those that are smug and brag about not having or watching a TV), rather than one per 80% of households back when it was a Commer van.

The only way I've heard of TV use being detected that I see as feasible was a directional microphone comparing sounds coming from people's houses with what was being broadcast at the time. Probably a lot more realistic when there were 3/4/5 channels in common use than 200+ channels.

I suspect we would have heard from someone who operated one by now if they existed. Bit like all the people who would have been involved in the fake moon landings.

And if it's operated by Crapita, or G4Less, or whoever, the BBC have outsourced it to, I wouldn't worry too much about them being able to find your street, let alone run complex equipment.

I had believed that there are some real detector vans, possibly not that many, and certainly not as many as there are fake ones.  Largely a PR stunt, but based on at least one real van.

I suspect we would have heard from someone who operated one by now if they existed. Bit like all the people who would have been involved in the fake moon landings.

They all all been silenced, like in that documentary Capricorn 1. Admittedly is was about Mars, but you know they did the same thing for the moon.

I couldn’t see them being a cost effective means of enforcement

Very true. With 21st Century IT and the fact that almost every house owns a TV, it would be a lot more efficient to simply contact the one without the licence at the address. You even have to give your name and address when you buy a new TV.

Although I think it might of been different in the 1970s.

It was probably more believable back in the 70s, I think less people had even a basic knowledge of tv signal technology.

Having worked in a few places which were subject to Tempest testing I’d say detector vans are certainly feasible

This. It's possible to detect emissions from certain types of receiving devices. Last time I was involved in this, it was with CRTs though. I'm not sure if it still applies for LCD/LED screens.

https://en.wikipedia.org/wiki/Tempest_(codename)

Does one really believe that the BBC or licensing authority would have had a fleet of vehicles roughly equivalent to the same effort that Google streetview is doing now, but in the 70’s/80’s? or the SatNav mapping companies?

I'm fairly sure I saw one in Glasgow from time to time in the 1980s.  Assuming it is not a fake memory, then I'd say the vans were real.  Whether they worked or were just a publicity effort is a different question.  Its nowhere near the same effort as Streetview.  1. They definitely sent people out to visit suspected rule breakers, those people needed transport; 2. You don't need to drive down every street to do license detection - firstly you can ignore streets where everyone is licensed, secondly if the aim was "fear" rather than "forensic detection" then you just need to be seen; 3. You can park the van up outside a block of flats for an hour and it will be seen by many, whilst costing nothing.  The cost of streetview is not so much the initial survey it is maintaining the changes, and the huge volumes of data collected.  They may be more analogous to trailer adverts than streetview.

I've read technical papers discussing the detection technology used for detecting the old CRT screens, so it was definitely feasible.

I suspect they might have had one working van for demonstration/PR purposes, but it doesn't sound economical to deploy a fleet covering the whole country.

Assuming they had access to that technology, would it have been cost effective over just trawling though licence records?

Last time I was involved in this, it was with CRTs though. I’m not sure if it still applies for LCD/LED screens.

A fair few years ago I saw a demo which "mirrored" a CRT display from over 100m away and I'm sure it wasn't their best kit on display. Modern displays are a lot less leaky but detection and processing power has also moved on exponentially. Still don't believe anyone would invest money on enforcing TV licences other than by door knocking though.

They used to have one that roamed near our house as Kids, my 'biological' father was, and probably is still a shady **** so we never had one.

They'd park outside and my Dad would tell us to turn the TV off. They'd knock on the door "We have reason to believe" all very official and ask "Can we come in for a chat" now they'd say it like it's just a turn of phrase as they're stepping over the threshold with all the authority in the world to do so - after all, long raincoat (the 80s version of high viz) laminated badge with a big crest on it - hell, they look like CID and he'd say "No" (usually more than no, but no will do)  and that would be it. Sometimes they'd claim they could see what we were watching. But he'd just say "Bye" (usually more than bye, but bye will do) and close the door. They'd shout loud enough for the neighbours to hear asking if he thought it was fair for him to be the only one without a licence and they'd return with a warrant, but they never did.

In case you're wondering, I have a license, always have done.

It's probably easier to get away with now, the burden of proof is still with them, I very, very much doubt Sky (who have been arguing for the abolition of the license fee for decades) would share data with them and you can politely refuse to give your details to the shop when you buy a TV, and they certainly don't check it.

This. It’s possible to detect emissions from certain types of receiving devices. Last time I was involved in this, it was with CRTs though. I’m not sure if it still applies for LCD/LED screens.

This is the gist of it you can detect a CRT, but it's hard to determine if it's a TV, PC or anything else, and not much is a CRT anymore. CRT's work with powerful magnets, a beam of electrons and a load of RF amplification circuits, compared to the rest of the contents of your average 70's terrace it would be pretty easy to spot.

That and unless they only watched TV in a back room with blackout blinds you could see what's on TV just driving down the street looking through living room windows,

So the technology was certainly available to drive down a street anytime before the mid 90's when PC's became more commonplace, and workout who had a TV set. Whether they did or not I've no idea.

It was probably more believable back in the 70s, I think less people had even a basic knowledge of tv signal technology

Turns out it's 2018 and you're still wrong :p

Big list of every address in the UK. Big list of every address in the UK that has a TV license. Subtract the latter from the former and filter to the lowest income areas. There is your detector van.

The local oscillator in any receiver (tv, radio whatever) generates its own RF signal which can be detected with the right equipment and with a directional yagi antenna and a signal strength meter you could have reasonable guess at locating the TV.

I believe they just use lists of houses with no licence and then try and either bully them into buying one or trip them up in an "interview" to admitting to watching live tv then take them to court.

However it would be impossible to detect what was receiving those signals as technically everything is receiving the signal

Nope, you can detect an analogue TV quite easily, their EM signature is very distinctive and quite easy to detect, you can even detect which channel they are watching if you're close enough. With modern digital TVs it would be much harder as the Em field will be much weaker.

I used to work on secret squirrel MOD projects and our offices had massive faraday cages over all the windows to stop anyone eavesdropping on the computer monitors as you can quite easily park a van next to an office and see what's on an analogue PC monitor in the office from the EM signature.

For the grade of work we were doing the office was a complete Faraday cage with no internet, no phones and only power (heavily filtered) coming in.

We didn't have a license for about 5 years a few years ago and the amount of bullying letters and doorstep visits bordered on harassment. Despite filling in the appropriate online form we were subjected to a concerted campaign from the governments finest and they indeed threatened us with sending a detector van to our street on many occasions. Never did though and hilariously all the doorstep visits took place in the day time when we were all out - not once did they come round in the evening when you would of thought the success rate might have been a bit higher. Fools.

TV "detector" vans do not exist and never have.

Vans that look like detector vans may exist - I read somewhere a few years ago that there were something like four of these in the entire country, though how reliable a source that was I don't know.

Threatening letters and men peeping through your windows to see if they can see you watching telly almost certainly exist.  They have no powers of entry and cannot force you to prove anything.  You do not need to nobble your TV / aerial or otherwise be physically unable to watch TV in order to legitimately not have a licence, you simply have to not watch or record broadcast TV or iPlayer.

If you watch TV, get a licence.  If you don't, ignore them and tell them to bugger off.

Back in the 70s or 80s I saw a program on TV that demonstrated the detector van technology. Couple of blokes in the back of a van looking at screens showing what folk were watching. Bloke in lab coat described how they worked, that the analogue tuners in CRT TVs reflected signal or gave off a lot of RF, and it was this they picked up on. Remember this was back in the days when CRTs were the only type of telly and will not have matched modern standards for RF emission shielding, houses back then were not full of electrical gear, wifi, etc. It was a totally believable demonstration of what was possible, but this doesn't mean it was practical or used extensively, I suspect just knocking on doors was found to be a more efficient method of detection, especially as telly ownership approached 100% (remember kids this wasn't always the case). Government owned monopolies of the time BBC / PO could also be very secretive about what they were doing, they built a telecoms tower in London that wasn't acknowledged for many years, and I think the myth of detection became stronger than the technology and they just rolled with it.

It was a totally believable demonstration of what was possible, but this doesn’t mean it was practical or used extensively

... or ever existed.  It would have been a mockup for a PR stunt.  Wouldn't be hard to rig up a screen to show "what people were watching" simply by, uh, turning on a TV in the back of a van.

I very vaguely remember watching something similar when I was a kid too.

The 'no licence list' is the main method now.

Recently there was a campaign where they targeted entire streets with no licence payees with billboards to shame them; it spectacularly backfired when they chose a Salford street where all the devout jews live that don't have telly on religious grounds, there was a big group of unhappy residents waiting for the local MP at the surgery...

Turns out it’s 2018 and you’re still wrong :p

I may may well be. Less knowledge means more fear of the unknown. My point is, could they detect the signal with enough accuracy to pinpoint it to ‘your’ tv in ‘your’ house to say decisively that it is you with a tv and no license and then go to court. If they could, why did and still do (crt aside) people get away with no license. It seems to me the fear factor was key in the vans even when detection is possibe.

http://emwatch.com/tv-radiation/

Tin foil hats or not.

Does one really believe that the BBC or licensing authority would have had a fleet of vehicles roughly equivalent to the same effort that Google streetview is doing now, but in the 70’s/80’s? or the SatNav mapping companies?

I think they were supposed to be around in the '60s. I'd have expected that in that time I'd have seen at least one. I've seen a Google van and they have only been around a few years. As has been said they have a couple of blokes with clipboards and an outrageous assumption that every household has a tv.

I have a relative who told me that the detector vans were real, they worked in the R&D department at the BBC so I had no reason to doubt them.

There are a few here citing the cost vs return angle as proof they don't exist. I don't wish to sound flippant but which rock have you been living under that leads you to think the government or a quasi government body wouldn't do something because it's too expensive, not going to achieve much and could be done more efficiently and successfully for a fraction of the cost some other way.

If anything makes me think the vans might be real it's the firm knowledge that if there's an expensive, ineffective and poorly planned method of doing things you can be pretty sure the government will roll it out.

I have a relative who told me that the detector vans were real, they worked in the R&D department at the BBC so I had no reason to doubt them.

https://yourlogicalfallacyis.com/appeal-to-authority

Someone submitted a FOI request to the BBC asking whether evidence from TV "detector" vans has ever been submitted in court.

https://www.whatdotheyknow.com/request/evidence_from_tv_detection_equip

Their final reply is here:

WHATDOTHEYKNOW.COM "https://www.whatdotheyknow.com/request/55922/response/164153/attach/4/IR2011006+TVL+response+following+IR+final.pdf"

Maybe don't be quite so dismissive Cougar. You can find reference to them in the contract with Capita  https://www.whatdotheyknow.com/request/190228/response/501441/attach/html/4/Schedule%2002%20Services.pdf.html

Yeah, I've just backtracked to their blog.

https://tv-licensing.blogspot.com/search?q=detection

Some interesting reading.

I live on The Isle of Man where you  need the same TV license as the UK . They have no detector vans over here but a few years ago there was a van and a crew to man it came over on the ferry but before they started work the IOM government stepped in and wouldn't allow it because the people operating the van did not have Isle of Man work permits and so they had to go back on the next ferry without doing anything .

I lived on Orkney in the early 90's and there was a story in the Orcadian one day re a Helicopter with a TV Detector that would be operating over Orkney and Shetland for a few weeks in summer.  It caused a minor uproar but I'm not sure anyone ever saw it.  I worked at Kirkwall Airport and I never did.

Mate of mine was BBC guy and no licence was one the the guaranteed losing your job offenses. There were TV Detector Vans waaay back in the day (60s/70s), I think he said 4or 5 for the whole country. The tech (!) was there but never really meant as anything other than a deterrent. Like Nukes.

a crew to man it came over on the ferry but before they started work the IOM government stepped in and wouldn’t allow it because the people operating the van did not have Isle of Man work permits and so they had to go back on the next ferry without doing anything

I’ve never needed a work permit.. and I’ve been on the island with vans that might look like detector vans if you didn’t know what you were looking at, and been involved with MHK’s who didn’t turf us off...

There are a few here citing the cost vs return angle as proof...

when you you put it like this then yes. However, if they have this capability how can people get away with no licence? Surely they could catch everyone as they drove around.

The old analogue TV signal was broadcast on about 20 channels between approx 470 and 850 MHz (UHF), with the picture and sound information being encoded with a frequency modulation technique.  That signal pretty much was everywhere, as the Transmitters were pretty powerful so as to be able to cover most of the uk population.  Detecting that signal therefore would be pointless, as it exists even if it's not being received by a TV

But, the old CRT TVs used a very specific display signal, where the screen was broken up into lines and an electron beam is scanned along each line, then reset and moved down a line and rescanned. As it travels across each line, the intensity of the beam is modulated to provide the necessary spot brightness at each pixel location.  A colour TV uses 3 beams, one for each colour, and each is modulated to provide the necessary luminousity at each moment in time.  In the uk, there were 625 lines, scanned at 25 Hz (ie the picture was completely refreshed every 25 Hz. so each line takes 64us to be built.

As the electron gun must be modulated at this rate, both it's signature and those of the steering electromagnets (those that deform the beam to enable it to sweep across the screen) are at a very specific, and very fixed rate.  And as an electron gun is excited by a high voltage, the RF emissions from that gun are extremely easy to pick up, even back in the 1970's!

A small device, consisting of a tuned receiver (ferrite core + windings + pass filter + amplifier set up as an integrator) costing a few tens of pounds can easily detect the presence of a CRT that is turned on, in a fairly narrow field of view.  You can't see what channel is being watched, but all you need is enough evidence to get a search warrant from the authorities.

So, whilst the pictures of BBC operatives watching exactly what people watched on their screens in the back of a van was, for TV detecting at least, a complete fallacy, i see no reason why a bloke in a car, or on foot with small handheld detect could not be used.

(As previously mentioned, it is possible to recreate and re-display the picture being formed on an unshielded CRT from a significant distance (several hundred meters), but is it more complex that simple detecting the presence of the picture forming going on, and requires a re-synchronisation of the screen scan and careful calibration of a suitable phase locked loop to provide a base timing signal of the appropriate frequency.  Modern LCDs are difficult to remotely acquire, because they drive an entire line of pixels at once, and that drive is at a low voltage, meaning much less RF emissions and only an opportunity to lock onto the vertical scan rate.  Harmonic analysis of the line data may allow a statistical approach to decoding each lines pixel data, but it would take a lot of computing power to do so in real time)

I had the same experience as winston describes. For a couple of years I didn’t have a TV and I had a lot of letters, verging on threatening. They blatantly couldn’t conceive that someone might not have a tv.

We went a number of years with no tv, there is like a routine of letters, each more threatening than the last, then they send someone round, then the letters reset.

all stopped when we eventually bought a tv and got the licence.

they sent us a lovely letter today to tell us we had overpaid by £49, so not all bad.

@maxtorque. Could a device pinpoint exactly where the signal was coming from? Say in a block of flats or a miners cottage row situation? Did the addition of of lead screening around the tubes affect this detection ability?