TV Licence Detector Vans - Urban Myth?

[INTERVIEWER]

You can get non-CRT sets that fulfil that criteria, such as THIS 20" LCD, bought from Cash Generator, for less the 80 quid.

 

Is this a TV or a monitor? Does it have scart connector sockets? Can it be hooked up to a DVD player or a console?

[Mondeo Man]

Is this a TV or a monitor? Does it have scart connector sockets? Can it be hooked up to a DVD player or a console?

 

It's a TV.

 

It had an aerial socket and an analogue tuner (until I did a bit of surgery on it ), and it has a scart socket, an S-Video socket, "phono" AV-IN sockets, and a PC Monitor socket.

 

SEE HERE.

 

I watch DVDs on it, using my DTS Home Theatre DVD player, all the time.

 

ETA. I've also attached a MESSAGE for any TVL bod that turns up with a Search Warrant.

[Obelix]

Just done some research and found this.

 

quote: They work by detecting the emission from the line flyback circuitry of the TV picture tube itself - nothing to do with local oscillators or intermediate frequencies in the receiver. Those frequencies are normally screened to avoid interference. The tube circuitry however, scans consistently at 15.625 kHz to move the electron beam across the face of the tube and that's what can be detected.

 

As I originally thought they do in fact detect the electron gun radiation.

 

Here is a simple experiment that you can do at home to prove a CRT TV can be detected.

 

1:Turn on TV.

2:Take a MW radio and place it near the tv.

3:Tune in the radio till you hear a constant buzzing sound.

4:Turn off TV and the buzzing stops.

 

The signal that causes the buzzing can be detected several meters away just with a simple radio.

 

Electron gun radiation consists of visible light from the tube phosphors and soft x-rays from bremstrahlung radiation as the electrons decelerate - you are not detecting the electron gun if you do that.

 

As many people have CRT's with non standard frequencies for frame flyback, or indeed no longer have CRT's a better way is to look for the local oscillators as I said. It's almost impossible to shield a LO as they reradiate back up the antenna wiring due to their design as the mixers are never very good, nor do they need to be very good.

[Mondeo Man]

It's almost impossible to shield a LO as they re-radiate back up the antenna wiring

 

So, presumably, you can't detect a set, if there's no antenna attached

 

Can you detect a similar signal, travelling back up a satellite cable, or is that something different

[Obelix]

So, presumably, you can't detect a set, if there's no antenna attached

 

Can you detect a similar signal, travelling back up a satellite cable, or is that something different

 

You can because the LO is always running but if there isn't anything attached at all then the signal is less.

 

However if you have the antenna coax plugged into your VCR/DVD player to transmit a signal in, then it will still have something to radiatae back out of.

 

The effect is very local, you would be hard pressed to find it from say a half mile off, but you can detect it close by. Can you do it with any accuracy to identify the precise house- well, that's the issue, I suspect you cannot easily do so, at least not to the standard that a court would require.

[Mondeo Man]

I sawed of the socket on my TV, opened the box containing the tuner circuit, and snipped off the inside connection ,from the aerial socket to the tuner circuit.

 

Does that mean the LO signal is now trapped inside the box, and no longer detectable

[INTERVIEWER]

The effect is very local, you would be hard pressed to find it from say a half mile off, but you can detect it close by. Can you do it with any accuracy to identify the precise house- well, that's the issue, I suspect you cannot easily do so, at least not to the standard that a court would require.

 

The BBC/TV Licensing claim that they have developed hand held TV detectors which are very accurate indeed, and can even pinpoint which room a television is located inside a block of flats.

 

Of course, this super accurate technology has never been used in a court of law to secure a conviction. The BBC claims that this is because it does not want the technology to be given a public airing, lest people find a way to neutralise it.

 

I am led to believe that TV 'cloaking' devices do currently exist, although I remain as sceptical about the effectiveness of this as I do about the BBC's TV detection equipment...

[Obelix]

The BBC/TV Licensing claim that they have developed hand held TV detectors which are very accurate indeed, and can even pinpoint which room a television is located inside a block of flats.

 

Of course, this super accurate technology has never been used in a court of law to secure a conviction. The BBC claims that this is because it does not want the technology to be given a public airing, lest people find a way to neutralise it.

 

I am led to believe that TV 'cloaking' devices do currently exist, although I remain as sceptical about the effectiveness of this as I do about the BBC's TV detection equipment...

 

If you used such a cloaking device that would be illegal as it's very unlikley you would ahve a licence to run one however....

[Mondeo Man]

If you used such a cloaking device that would be illegal as it's very unlikely you would have a licence to run one however....

 

Wouldn't that depend on how said "cloaking device" worked

[Obelix]

Wouldn't that depend on how said "cloaking device" worked

 

They generally work by transmitting a masking signal, which means unless you are licenced to build and operate a transmittor you are going to be violating the communications act.

 

As well as perverting the course of justice etc etc...