How it Works: TV Detector Vans

[ayceejay]

A guy who normally worked behind the counter at the PO knocked on my door one day, it was a surprise to see him so I wondered what is purpose was. He had come to collect my TV license money he said, there was no Dr Who detector van parked outside so I asked how he knew that I had a TV but no license. The second part of my question was too easy but he said that when someone buys a TV the licensing authority is notified but the real reason was that they reckoned everyone had a TV so everyone should have a license. I told him that I didn't have a TV or a license and he went away.

 

[Leedsbusdriver]

 

[ufkacbln]

At the moment it is all about timing.

If you have a license than you can watch streamed content at the time of broadcast on any item, wherever you are, you an also watch content through a DVD player, digital box or similar.

If you do not have a license then you can only watch content after it has previously been shown then you do not need a license

The uncertainty comes because back in the late 2000's there was an attempt to make licenses for mobile phones etc a requirement if they could receive content

 

[sheddy]

So, can I just watch TV on the Iplayer, with a 1min lag ?

 

[ColinJ]

So, can I just watch TV on the Iplayer, with a 1min lag ?

You have to wait for it the 'live' broadcast to finish first. There is no apparent logic to this!

 

[G3CWI]

It used to be the case that due to the way they worked, televisions transmitted a radio signal while switched on. This signal (the line timebase oscillator) was detectable some distance away. This oscillator was needed in all cathode-ray tube displays. That was what the detector vans looked for. At the time (1970s hand early 80s) the TV was the only thing people were likely to have that would emit this characteristic signal. However as time went on people had similar screens for computers making the van's task harder. But the final nail in their coffin was TVs using LCD displays which were mostly undetectable. At that point the vans were useless.

 

[fossala]

You have to wait for it the 'live' broadcast to finish first. There is no apparent logic to this!

There is logic. What it means is that anything that was every on TV isn't controlled by them criminals (TV licencing).

 

[swansonj]

It used to be the case that due to the way they worked, televisions transmitted a radio signal while switched on. This signal (the line timebase oscillator) was detectable some distance away. This oscillator was needed in all cathode-ray tube displays. That was what the detector vans looked for. At the time (1970s hand early 80s) the TV was the only thing people were likely to have that would emit this characteristic signal. However as time went on people had similar screens for computers making the van's task harder. But the final nail in their coffin was TVs using LCD displays which were mostly undetectable. At that point the vans were useless.

My physics teacher told us it was the superheterodyne frequency that was detected. That is likewise produced when the telly is on. I think that would be specific to TVs and not to any other uses of CRTs, but it is certainly possible to have digital receivers that don't use superhet. Perhaps the detector vans use/used both?

 

[threebikesmcginty]

If you watch TV without a licence then you can't complain about how shite the BBC are, it's the only reason I buy one.

 

[Mad Doug Biker]

There is logic. What it means is that anything that was every on TV isn't controlled by them criminals (TV licencing).

The original point of broadcast has passed, does watching it a few mins later or a few hours/days later really matter?

Besides as long as the BBC are able to edit or rebroadcast versions of something, they will always be controlling it in some way. The original point of broadcast is only one point in possibly many, potentially over several years (repeats etc), so where do you draw the line?

 

[dodgy]

If you have a license than you can watch streamed content at the time of broadcast on any item, wherever you are,

In the UK, then. We go to France every July (for some reason, wife has cottoned now I think...) and I have to set up a VPN account to watch BBC (and ITV etc) catch up and live services over the Internet.

I imagine the admin involved in allowing any Brit who is travelling to have access would be a PITA.

 

[MontyVeda]

It used to be the case that due to the way they worked, televisions transmitted a radio signal while switched on. This signal (the line timebase oscillator) was detectable some distance away. This oscillator was needed in all cathode-ray tube displays. That was what the detector vans looked for. At the time (1970s hand early 80s) the TV was the only thing people were likely to have that would emit this characteristic signal. However as time went on people had similar screens for computers making the van's task harder. But the final nail in their coffin was TVs using LCD displays which were mostly undetectable. At that point the vans were useless.

If a TV can transmit a radio signal, does that mean you'd need a broadcasters licence too?

 

[Black Country Ste]

You need a TV licence for that.

It can be checked through your ISP.

Nope. You need a TV Licence only if you watch or record TV as it is broadcast, which includes iPlayer. Catchup services are OK to use without a licence.

 

[MontyVeda]

Slightly off topic... but the BBC don't exactly make it hard for non-licence holders to watch live programming via the iplayer... all you do is click on 'watch live', then a warning appears saying you must have a licence to watch this, and then you just click to watch... as a non licence holder, I'd have expected them to say 'key in your unique ref# from your licence to proceed'.

Just because i can watch live TV via my PC doesn't mean i do... but watching catch up on the iplayer, how do they know I'm doing one and not the other??? I'm not on a static IP, as most people aren't.. so how does their IP tracking work?

 

[bof]

Slightly off topic... but the BBC don't exactly make it hard for non-licence holders to watch live programming via the iplayer... all you do is click on 'watch live', then a warning appears saying you must have a licence to watch this, and then you just click to watch... as a non licence holder, I'd have expected them to say 'key in your unique ref# from your licence to proceed'.

Just because i can watch live TV via my PC doesn't mean i do... but watching catch up on the iplayer, how do they know I'm doing one and not the other??? I'm not on a static IP, as most people aren't.. so how does their IP tracking work?

There are a number of databases out there that give the approximate location of an IP address. There is an open one (whose name now escapes me) and a number of higher quality commercial databases. ISPs like BT will have a bank of IP addresses usually allocated dynamically to users connected to a data centre/exchange. They are generally used to target advertising, but the BBC uses one for checking to see if an IP address is in the UK. The better databases can give you a good idea when you are being accessed from a "high-risk" IP address (such as an anonymous VPN) but since the BBC is not taking money it does notseem to bother to restrict those. The UK only restriction on iPlayer is because they frequently only have the rights to broadcast within the UK and because they carry advertising on services aimed abroad.

It's not infallible as a multinational may use a location outside the UK as its internet connection point. Last year I couldn't watch the cycling at the Olympics from work on the BBC as it thought I was in Switzerland - thankfully Eurovision ran a feed from each venue which I could pick up (and get an English commentary). If you find you are get advertising targetted at the other end of the country from where you live, btw, the odds are your local conenction point is down and BT or whoever are routing you via a fallback.