TV Detector Vans

[hamid_1]

I've only seen a TV detector van once, about 10 years ago. It was driving slowly round a council estate at 8 o'clock in the evening. Whether it was real or just meant to scare people, I don't know.

I remember seeing the TV ad where the detector man says "they're watching Columbo!". You can see the ad online on youtube and the National Archives - there's a nice shot of the detector van supposedly in action.

I kind of suspect that they detect the channel you are watching by looking at the flickering light given off by the TV screen. You can do this yourself if you walk down a street at night and look into the windows of the houses. The light coming from behind the curtains changes according to the scene being shown on TV. The detector van would only have needed a few portable TVs tuned in to the main channels. If the pattern of light coming from the house follows the TV in their van, they can tell they're watching the same channel.

[richrussell]

Much easier when there were only a couple of channels too. Especially if you do it when there's a football match on - lots of nice bright green light

[Phil G4SPZ]

Er... when there were only two channels, weren't they both black-and-white?

[richrussell]

I was thinking about the 1970s/80s which was the period being discussed more recently. I certainly remember walking home from my mate's house when the 1982 World Cup was on, and every house had a green glow in the living room.

[DallasHJones]

as 'hamishdoctor' says above, I recall that the detector vans picked up an 'element' or section in our televisions. This even applied when the set is off. That way they knew a set was within a measured section.

I believe this is so as when i was a kid they knocked lol. I believe in later years they could detect what was being watched but this may be a myth. I'm sure now most of us are online with tv this principle in redundant and they use another method.

personally i think the bbc should have adverts now, the licence is a farce and they make so much money from bbc enterprises and merchandise.

D

[stevehertz]

Not even sure if they have them now, but re the old style tv detector vans, how good or accurate were they at pinpointing a property with an operating tele in it? Just that someone on a social media page is saying that in anything other than a remote area their effectiveness was pure kiddology. My thoughts are they were pretty effective units. I'll stand corrected though.

[HamishBoxer]

I think they caught a good few folks and listened for the line t/base also on colour the 4.443 Ref oscillator.

[dave walsh]

Loads of threads to read through Steve. This subject was an ongoing topic/enigma at one time, like most in fact! As I recall, just as some sort of consensus was reached...ie that it was all "black-ops" PR, the Vans didn't really exist and couldn't detect offenders if they did then...someone came on and said it was his job in the GPO and gave details about it I'm sure I printed that out!

Dave

[Refugee]

A lot of it was done with a small TV in a car and visual comparison between the program on the set and the variation of the shadows on the curtains of the home under investigation.
The vans with big aerials were mostly for show and had small aerials for doing signal strength testing while they were out there on visual duty.

[Station X]

Since being reopened this thread hasn't become an anti TV Licence or anti BBC rant.

Let's keep it that way please. Politics have no place here.

[dave walsh]

I had a visit from the authorities once [in the seventies]. I'd just moved and rented a colour TV. It was two chaps [in a saloon car]. They seemed to be working from shop records. I did have a B+W license and just paid the difference "on the spot". I think it was £20!

Dave

[Graham G3ZVT]

Do dealers still have to supply to "The Authorities" the names and addresses of the customers they sell television equipment to?

[McMurdo]

from Capita's 'TV Licensing' web pages


TV dealers:

The Wireless Telegraphy Act of 1967 (as amended) has been repealed, meaning that from 25 June 2013 onwards you no longer need to send us customer name and address details when you sell or rent out TV equipment. This also means your business no longer has to keep sales records to comply with the law on TV Licensing. If you don’t need these records for anything else you can destroy them from 25 June.

[Refugee]

I used to know a bloke who lived in quite a posh block of flats in the 1970s.
He bought a fairly posh telly and paid cash for it. When they asked for his address he picked it up in its huge cardboard box and bolted off.
He got away with it for ages without a license.

[Top Cap]

I met a TV detector man one day and he told me they used pick up from the local oscillator to find what station someone was tuned to. He said, "If you can make a UHF TRF set then I would not be able to detect the TV". Never discovered if he was telling the truth or not but if he was, the chances of making a TRF at UHF was I think a complete no no unless you lived very close to the transmitter?

[Radio Wrangler]

You wouldn't need to do a TRF, just a receiver with a significantly different IF, so LO radiation wouldn't be where they were looking.

With a low-gain log-periodic antenna into a low noise amp and a spectrum analyser, I could easily see emissions from local TVs at an open-air EMC test site. You had to keep turning the thing you were testing off and back on to see which emissions came from the device you were testing, and which were already in the environment. I'd spotted groups of unmodulated tones in the UHF TV band and wondered what they were, then I had a Duh! moment when the significance of them being about 40 megs off of the locally used channels sank in.

With the amateur radio set up at home, there were troublesome line scan harmonics over a lot of the MF and HF bands. With a portable RX and a loop antenna, I could DF the sources.

So, some detectoring could be done, but I suspect that their most powerful tool would be a list of addresses without licences. 'Could' isn't the same as 'did' and the things atop the occasional van I saw looked like styling exercises done in a primary school art class.

David

[HamishBoxer]

Yes,I thought this thread had been re opened and certainly no ranting needed.

As I stated earlier the method used to detect,I am afraid I have never seen one though.

Though a year or so back do I remember one being restored somewhere?

I have a Post Office receiver or I certainly used to have with d/finding on.

[Rubberfingers]

Originally Posted by Refugee

I used to know a bloke who lived in quite a posh block of flats in the 1970s.
He bought a fairly posh telly and paid cash for it. When they asked for his address he picked it up in its huge cardboard box and bolted off.
He got away with it for ages without a license.

I knew someone who bought a new colour TV, and gave his fathers address as he did'nt want to buy a license. What he did'nt realise was that his father did'nt have a license either, so when his father started getting letters from TV licensing, he had to buy his father a license!

[G6Tanuki]

Having always lived in relatively rural areas the prospect of a "TV Detector van" was never really a concern - in the 1980s there was always more panic over bright-yellow-painted Bedford CF vans with antennas on the roof.

Rumour that a "Buzby" had been spotted in the area had everyone hiding their CBs and taking their 'twigs' down!

[emeritus]

Circa 1980 I remember reading a piece in the "New Scientist" about how the BBC had acquired a computer with enough memory to store every address in the UK that they were going to use to find all the addresses that didn't have a TV licence. I had bought my first house in 1975, which had been unoccupied for more than a year, and as I couldn't afford a TV, didn't have a licence. A few months after the article appeared I did get a visit from someone asking if I had a TV.

I guess that the acquisition of the computer meant that there was no longer a need for detector vans.

The closest thing to a detector van I have seen was when I had problems when the BBC introduced the RDS system on FM. They did send an engineer round to check it wasn't due to multipath. He had a Land Rover-type vehicle with an aerial mounted on a telescopic mast that he extended and rotated around, much interest from the neighbors! There was a rack of test gear inside, but I don't recall what it was.