[sci.electronics] Television detection.

michael@fe2o3.UUCP (Michael Katzmann) (01/30/90)

In article <1273@otc.otca.oz> brendan@otc.otca.oz (Brendan Jones) writes:
   >in article <2981@servax0.essex.ac.uk>, zotog@sersun0.essex.ac.uk (Zotos G) says:
   >> In UK they use a system (detector, presumably a sort of receiver) to detect
   >> a non-licence TV household.
   >
   >Is this true???? I can't believe that you still need a licence in the UK to 
   >own a TV set (or perhaps use one?).  TV licences were scrapped in Australia 
   >in the late '60s, and from what we hear in Oz about Maggie's right wing Free
   >Market society I would have thought such an antiquated and absurd impost
   >would have gone long ago.
   >-- 
Actually Australia got rid of the Licence fee in 1973 because it was a
regressive tax. i.e. the fee as a percentage of your income was higher for
a low income earner than for the more affluent.  The government of the day
was concerned for the ordinary citizen (A rare thing).   Somehow I don't
think those sort of inequalities matter very much to the Thatchers
of this world.

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Broadcast Sports Technology.
2135 Espey Ct. #4
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brendan@otc.otca.oz (Brendan Jones) (01/30/90)

in article <8ZkkfpG00Uh780mlR=@andrew.cmu.edu>, bb1v+@andrew.cmu.edu (Barry Lowell Brumitt) says:
> The reason is quite simple, BBC I and BBC 2 have no commercials. Their
> funding comes entirely from the licensing fee.  I am sure I would pay $80
> a year here for good channels with no commercials.

In Australia the funding for the two public stations (neither of which shows
commercials, although they have a lot of 'in house' promotion) comes directly
from Government general taxation revenue.  Both stations (ABC and SBS) are
excellent and have nationwide coverage.

Australia also has three major national commercial networks plus a myraid 
of regional ones.

I would have thought the bureaucracy required to administer a licencing body
plus equipment and people to detect 'unauthorised' use of TVs would be a very
inefficient way of funding a public TV station.
-- 
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ngc@chanel.UUCP (Chris Ng) (01/31/90)

In article <428@ssc.UUCP>, markz@ssc.UUCP (Mark Zenier) writes:
> In article <2981@servax0.essex.ac.uk>, zotog@sersun0.essex.ac.uk (Zotos G) writes:
> > In UK they use a system (detector, presumably a sort of receiver) to detect
> > a non-licence TV household.
> > 
> > Does any out there has any idea of how this is done?
> > What exactly they detect ?
> 
> An article (lost in the mists of time ) make me think they use leakage out
> of the IF, since they were listening for the sound.
> 
> Another system picks up the horizontal sweep, and compares the phase to
> determine which station is being received.
> 
> markz@ssc.uucp

How do they know the TV household is a non-licenced one? 


  












-- 
Chris Ng
UUCP: {asuvax | hrc}!gtephx!ngc

zotog@sersun0.essex.ac.uk (Zotos G) (01/31/90)

Well, it is true that in England they detect non licence households with two ways.
One is with a van with lots of antennas at the top and the other with some sort of portable detector which is used to places where the van can't go.

Is  any one out there,who knows how it is done?

Thenks.

jack@cs.glasgow.ac.uk (Jack Campin) (02/01/90)

ngc@chanel.UUCP (Chris Ng) wrote:
> zotog@sersun0.essex.ac.uk (Zotos G) writes:
>> In UK they use a system (detector, presumably a sort of receiver) to detect
>> a non-licence TV household.
[ electronic details omitted ]
> How do they know the TV household is a non-licenced one? 

The TV licencing authority has a database listing everyone who's paid their
licence fee.  They match this against whatever records they can find about
people.  If they discover you exist and don't have a licence, they will
send you warning letters, or even send an inspector round, on the
presumption that you have a TV unless you can prove otherwise.  Electronic
detection doesn't play a major role; most of it's bluff and intimidation.

I suspect most of the names come from the Driver and Vehicle Licencing
Centre in Swansea, the biggest database of personal information in the UK
(much used by the police for purposes having nothing to do with motor
vehicles).  As I've never had a car or driving licence in the UK, I was
ignored by the TV licence inspectorate until last year.  After getting
registered for the poll tax, I got two threatening letters from them within
weeks (no, I've never had a TV).

Other circumstantial evidence makes it virtually certain that's where they
found out about me.  The poll tax registrar presumably passed on that
information as part of a swap with either the licence inspectorate or the
DVLC.  To get people registered for the poll tax, every imaginable source
was used - employers' personnel records, health board files, student rolls
at colleges, the lot.  I doubt if it was coincidence that the introduction
of the poll tax coincided with the biggest swoop on licence-dodgers for
years.

For more information about government databanks in the UK, see Duncan
Campbell and Steve Connor: "On the Record: surveillance, computers and
privacy - the inside story", Michael Joseph, London, 1986, ISBN 0 7181
2576 2.  It predates the poll tax; an update is badly needed.

-- 
Jack Campin  *  Computing Science Department, Glasgow University, 17 Lilybank
Gardens, Glasgow G12 8QQ, SCOTLAND.    041 339 8855 x6044 wk  041 556 1878 ho
INTERNET: jack%cs.glasgow.ac.uk@nsfnet-relay.ac.uk  USENET: jack@glasgow.uucp
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BCOLLINS@zaphod.axion.bt.co.uk (Bill Collins) (02/01/90)

From article <48591bd2.1fbc0@chanel.UUCP>, by ngc@chanel.UUCP (Chris Ng):
> In article <428@ssc.UUCP>, markz@ssc.UUCP (Mark Zenier) writes:
>> In article <2981@servax0.essex.ac.uk>, zotog@sersun0.essex.ac.uk (Zotos G) writes:
>> > In UK they use a system (detector, presumably a sort of receiver) to detect
>> > a non-licence TV household.
>> > 
>> > Does any out there has any idea of how this is done?
>> > What exactly they detect ?
>> 
>> An article (lost in the mists of time ) make me think they use leakage out
>> of the IF, since they were listening for the sound.


> 
> How do they know the TV household is a non-licenced one? 
> 
> 

[bits deleted]
 


In the UK, everyone who uses a TV (B&W or Colour) needs a licence.
[Note: this causes some anomalies, such as the use of a TV as a monitor
for a computer, which is deemed as being a TV even if you never use it
as such]

[We also used to have to buy licences for radio receivers, but that was
scrapped way back in my youth! ... note though, that in the UK we can
only legally listen to "broadcast" and amateur stations, but that's another
topic]

In general, you need one licence per household (which covers any number of
sets in it); although there are some complications about hotels and other
"sub-let" properties: I do not know all the details.

To "assist" in people obtaining a licence, I believe that it is a requirement
of shops selling a TV that they notify the authorities every time someone
buys one. Thus a database can be built up of households in the country
which are known to have a TV, and similarly from the records of licences
issued, a cross-check as to whether they hold a TV licence.

The task of "policing" the TV licences is given to the Post Office, who also
sell the licences (and who, usefully, have lists of all properties in the
country!).

However, instead of checking every house in the kingdom and asking ...

	a) Do you have a TV, and if yes:
	b) Do you have a licence

... they have actually used a bit of lateral thinking, and instead they
operate on a list of households which do NOT hold a current TV licence.
Thus, they have a much shorter list of properties (most people are honest).



In general, "they" announce in advance which part of the country they will
be sweeping next, in order to give recalcitrant users the chance to buy
a licence before the detectors move in (ask about the silly TV "commercials"
they produce). They may also go around independently of the detectors,
knocking on doors and politely asking to see your (non-existent) licence ...
can anyone confirm this?

The detectors are in fact vans equipped with radio receivers and directional
aerials, which are driven past peoples houses; although I believe that
hand-held receivers and aerials are now used for checking awkward places
(eg. blocks of flats) on foot.

If I remember rightly, the detectors pick up the local oscillator signal
which leaks from the case of poorly shielded TV's (ie. all of them).
The receiver is usually a panoramic type, and so it is easy to see the
signals as the aerial sweeps past a house. By knowing which channels the
local transmitter is on, it is easy to see which station is being received
by the occupants ... hence, when they knock on the door, they know exactly
what you have been watching!


Unfortunately, this method of checking only unlicenced properties means
that people who do NOT own a TV (yes, there are some strong-willed people
around!), are more likely to get reminders through the post and persistent
visits than people who do.


Now ... you WILL buy a licence without being asked, WON'T you ?!?



	Regards,
		 Bill Collins.
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hanavin@udel.edu (Chuck Hanavin) (02/01/90)

In article <3027@servax0.essex.ac.uk> zotog@sersun0.essex.ac.uk (Zotos G) writes:
>Well, it is true that in England they detect non licence households with two ways.
>One is with a van with lots of antennas at the top and the other with some sort of portable detector which is used to places where the van can't go.
>
>Is  any one out there,who knows how it is done?
>
>Thenks.

Although not a two-way scheme, They could sit out in front of
your house with highly directional loop antenna and a reciever
tuned to the tv's mixer oscilator frequency. If they pick up a signal,
most likely you have a TV.

Chuck(WB3FJJ)

sutherla@hwee.UUCP (I. Sutherland) (02/02/90)

In article <1273@otc.otca.oz> brendan@otc.otca.oz (Brendan Jones) writes:
>in article <2981@servax0.essex.ac.uk>, zotog@sersun0.essex.ac.uk (Zotos G) says:
>> In UK they use a system (detector, presumably a sort of receiver) to detect
>> a non-licence TV household.
>
>Is this true???? I can't believe that you still need a licence in the UK to 
>own a TV set (or perhaps use one?).  TV licences were scrapped in Australia 

  After some court case the judge in question ruled that a license was 
required for owning a device capable of TV reception, whether you actually
watch it or not is immaterial.
  As for being done for it - it does happen an the minimum fine is 200 pounds
sterling.


-- 
Iain A. Sutherland             JANET:sutherla@uk.ac.hw.ee
B.Eng. Elec.Eng. IV             ARPA:sutherla@ee.hw.ac.uk
                               ...!mcvax!hwcs!hwee!sutherla

s872607@chudich.co.rmit.oz (George Tzanatos) (02/03/90)

zotog@sersun0.essex.ac.uk (Zotos G) writes:

>Well, it is true that in England they detect non licence households with two ways.
>One is with a van with lots of antennas at the top and the other with some sort of portable detector which is used to places where the van can't go.

>Is  any one out there,who knows how it is done?

They probably use the hf radiation generated by the sweep circuitry (etc) in 
the set, as previously mentioned in several articles.  If this is true, then
why not just shield the set using a faraday cage, and orient it such that the
tube points towards a neighbour's house...?
 
 George Tzanatos.

dave@stcns3.stc.oz.AU (Dave Horsfall) (02/05/90)

In article <3027@servax0.essex.ac.uk>,
    zotog@sersun0.essex.ac.uk (Zotos G) writes:

| One is with a van with lots of antennas at the top and the other with some
| sort of portable detector which is used to places where the van can't go.
| 
| Is  any one out there,who knows how it is done?

Well, as the man in the cat-detector van said, their equipment can pinpoint
a purr at 100 paces, and Eric, being such a 'appy cat, was a piece of cake!

Oops sorry - wrong newsgrope...

-- 
Dave Horsfall (VK2KFU),  Alcatel STC Australia,  dave@stcns3.stc.oz.AU
dave%stcns3.stc.oz.AU@uunet.UU.NET,  ...munnari!stcns3.stc.oz.AU!dave

greg@sj.ate.slb.com (Greg Wageman) (02/07/90)

Opinions expressed are the responsibility of the author.

In article <1990Jan31.182757.6731@axion.bt.co.uk> BCOLLINS@.axion.bt.co.uk writes:
>
>In the UK, everyone who uses a TV (B&W or Colour) needs a licence.
>[Note: this causes some anomalies, such as the use of a TV as a monitor
>for a computer, which is deemed as being a TV even if you never use it
>as such]
>
>The detectors are in fact vans equipped with radio receivers and directional
>aerials, which are driven past peoples houses; although I believe that
>hand-held receivers and aerials are now used for checking awkward places
>(eg. blocks of flats) on foot.

Which Monty Python satirized wonderfully in their "Fish License"
sketch.  You know, the one that starts out with John Cleese saying

"I would like a license for my pet fish, Eric."
.
.
.

"The man from the cat detector van."

"What cat detector van?"

"From the Ministry of 'ousinge."

"'ousinge?"

"It was spelled that way on the van.  I'm very observant.  He said
their equipment could pinpoint a purr at 50 yards, and Eric being such
a happy cat, was a piece of cake."

Copyright 1990 Greg Wageman	DOMAIN: greg@sj.ate.slb.com
Schlumberger Technologies	UUCP:   {uunet,decwrl,amdahl}!sjsca4!greg
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