So a quick bit of research and I seem to be coming up trumps. The principles the BBC/TVLicensing tout are reasonably sound, and it is a principle of picking up modified UHF (modified to 39kHz), these principles only work with analogue signals (personally i use free view, which is digital), and it only really works with older CRT monitors. But its a principle, not a real thing.
The heat maps shown above, called spectrograms, demonstrate that it is extremely hard to detect a working TV. Trying to detect a TV from the streets requires technology so advanced even the BBC, with its guaranteed yearly income, is not willing to invest in. More important: No one has ever been prosecuted on the basis of TV Detection evidence. You see, evidence cannot be heard in a court of law unless it is available to both the prosecution and the defence, and since TV Licensing and the BBC refuse to disclose the technology they use, detection results cannot be admitted as evidence.
So, three things backing up the point that it doesn't work;
1) The principles only work in short range in a clean environment
2) Making it work at range is extremely expensive, and the BBC dont bother with the investment
3) It is spying, illegal and not submissible evidence
Mickey, i've got to ask, is there something more to it than what the Beeb spout on there website? And did you actually do the detecting, or where you one of the foot soldiers, it was my impression they just have a big number of temp foot soldiers and very few permanant staff.
Pays well, looked at doing it a few times now, but after having to deal with the aftermath of one of these lieing bastards, i have very little respect for the profession and tactics employed. The scumbag that came round asked a manner of questions similar to those below (as a note this is a 8 tenant shared house, seperate contracts, locked rooms);
question : Do you own a TV?
my answer : No i dont, dont know about anyone else.
answer he submitted to the TVLicensing : Yes
question : If you had a TV what channels could you receive
my answer : God knows, the same as every one else i guess
answer he submitted to the TVLicensing : Regularly watches BBC1, BBC2, ITV, C4, C5
question : Do you have internet and what is your supplier?
my answer : Yes, Telewest i guess
answer he submitted to the TVLicensing : Has telewest set top box
question : How long have you lived at this address
my answer : 3 months or so
answer he submitted to the TVLicensing : Has lived in the premises without license for 18 months
and a long list of other bollocks. I still have some of it some where. Suffice to say two days later i got a demand of overdue payment for a license, very closely followed by threats of court summons, all in my name! Fucking diabolical. Multiple complaints to TV Licensing where met with 'you'll have to pay' or 'someone will get back to you'. Never did, caused more and more trouble. What a joke. In future i will answer any of them with one simple question, do you have a warrant? No, oh well, good bye!