Options For Receiving TV In The UK
Analogue Terrestrial Television
What we used to call simply TV  -  the more complicated name simply distinguishes it from other more recent options.  Channels available are BBC1, BBC2, ITV1, Channel 4, & Five.
In Reading, with a suitable aerial, depending on the transmitter it's aimed at, we can receive:
Transmitter	Aerial Group	Channel Number	Frequency (MHz)	Channel Name	
Croydon?	C/D (Vertical)	37	602	Five	
Crystal Palace	A (Horizontal)	23	490	ITV1 - Carlton/LWT	
Crystal Palace	A (Horizontal)	26	514	BBC1 - South East	
Crystal Palace	A (Horizontal)	30	546	Channel 4	
Crystal Palace	A (Horizontal)	33	570	BBC2	
Hannington	E (Horizontal)	35	586	Five	
Hannington	E (Horizontal)	39	618	BBC1 - South	
Hannington	E (Horizontal)	42	642	ITV1 - Meridian	
Hannington	E (Horizontal)	45	666	BBC2	
Hannington	E (Horizontal)	66	834	Channel 4	
Hemdean	C/D (Both)	49	698	BBC1 – South	
Hemdean	C/D (Both)	52	722	BBC2	
Hemdean	C/D (Both)	56	754	ITV1	
Hemdean	C/D (Both)	59	778	Channel 4	
Hannington, SE of Reading, and Hemdean, NE, are the correct transmitters for regional news, etc.  Depending on local geography, most parts of the area would probably get best reception from Hannington, some to the East from Crystal Palace, some to the North from Hemdean.  Five is not received very well.  Interference can be a problem, from old central-heating thermostats, and TETRA radio communications used by emergency services.
Analogue switch off, the date by which all analogue terrestrial services will have ceased to transmit as conversion to digital completes, keeps getting put back  -  the original date has already passed.  Crystal Palace, Hannington, and Hemdean are all currently scheduled for 2012.
Technically, for the purposes of UK broadcasting, the UHF TV frequency band is divided into channels designated by numbers 21 - 68 such as in the table above and that you used to see on the tuning knobs on old TVs.  Channels are grouped so that:
•	Consumer aerials can be optimised for best reception in any given locality;
•	Neighbouring transmitters whose signals overlap in areas between them can use different groups so that their signals don't interfere with each other in such areas.
Traditionally, groups covered small frequency ranges to achieve the best possible realisation of these factors, but recently, particularly since the arrival of Five and Digital Terrestrial Television, new groups covering wider frequency bands have been introduced.
Group	Cap colour on aerial	Channel Range	
A	Red	21 to 37 	
B	Yellow	35 to 53	
C/D	Green	48 to 68	
E	Brown	35 to 68	
K	Grey	21 to 48	
W	Black or none	21 to 68 - that is, all of them, aka WideBand	
Broadcasting is via a network of ground-based transmitter masts in analogue, 4:3 aspect ratio, 625 lines, PAL (UK standard).
Digital Terrestrial Television (DTT)
In recent years, broadcasters have introduced digital broadcasts from the same transmitter masts as the original analogue broadcasts.  In the UK, these are commonly called Freeview, but an international term such as DTT is preferable.
Consumers with a suitable aerial and either a Set‑Top Box (STB) or a TV with a digital tuner,  can receive about 80 TV and radio channels without subscription ...
http://www.freeview.co.uk/home
... and a subscription service from Top-Up TV ...
http://www.topup.tv/
Currently, here in Reading, we can receive DTT from Hannington or Crystal Palace.
Technically, broadcasts are DVB-T, mostly widescreen 16:9 aspect ratio, 6 to 19 channels being multiplexed (muxed) into the bandwidth formerly occupied by a single analogue one.
There may be problems in receiving DTT via an existing aerial if it was not recently installed.
In some areas, to squeeze digital broadcasts between existing analogue ones without causing unacceptable interference to analogue reception, mux frequencies may lie outside existing analogue groups.  Further, to avoid interference to neighbouring areas, on any given transmitter DTT power is often lower than analogue, and may also be directional.  So, an existing aerial that receives analogue well may not operate over frequencies outside of its designated group range effectively enough to pick up all or even any of the DTT muxes in that area.  Further, where the bandwidth of an aerial can pick up DTT transmissions, in marginal areas their reduced power may not be sufficient to drive a receiver.
The easiest way to test an existing aerial is to try and borrow a friend's, neighbour's, or relative's STB for an evening, and see if DTT can be received on it.
In built-up areas interference may have a more serious impact on DTT than on analogue.  This is discussed more fully in the section Analogue vs Digital.
Cable TV
In Reading this means digital cable TV from Virgin Media, formerly NTL/Telewest, formerly NTL, formerly ATT:
http://allyours.virginmedia.com/index.html?buspart=buyat
As its name suggests, Cable TV requires a cable connection to your property, so is only ever likely to be available in built-up areas.
All channels are encrypted and only available via monthly subscription and a STB.
Satellite TV
As far as the UK is concerned, there are four major subdivisions of Satellite TV:
1	Free‑To‑Air (FTA)  -  (inc Freesat) Digital TV from the 28.2E Eurobird Satellite Cluster
Some channels available free via UK DTT are also broadcast unencrypted from 28.2E, and so can be received by any industry standard digital satellite receiver.  Important inclusions are the BBC, ITV, Film 4, and Channel 4 channel sets, and Five.
In principle, as this is the same satellite cluster that BSkyB use, those with a working BSkyB dish (for example those who live in a home previously occupied by subscribers) can just buy a receiver and connect it up.  In practice, a good plan would be to try and borrow one for an evening beforehand to test that the dish is still working and correctly aligned.
Although the broadcasts themselves have been available already for some time on industry standard receivers, the UK’s Freesat service launched in May 2008, introducing on Freesat receivers extra functionality such as a full Electronic Programme Guide (EPG).  However, as this is a departure from previous industry standards, some Freesat receivers may not be able to tune to FTA but non-Freesat channels.
Official website:  http://www.freesat.co.uk/home.php
2	Freesat from Sky  -  Digital TV from the 28.2E Eurobird Satellite Cluster
This is a misnomer the Advertising Standards Authority should pursue  -  it is not free; you pay BSkyB a one-off but hefty fee of £150, and they install a BSkyB receiver and dish.
Although the result is more channels than other options, in practice nearly all those you would probably want to watch are already available by other, cheaper options.  Exceptions are those channels from the Five sets unavailable via analogue or DTT, and some sports channels.  Disadvantages are the price tag and the incompatibility mentioned in the note below.
http://www.freesatfromsky.com/
3	Sky  -  Digital TV from the 28.2E Eurobird Satellite Cluster
This is an encrypted subscription service from BSkyB:
http://www.sky.com/portal/site/skycom/products/packages
BSkyB Incompatibility:  A significant aspect of options 2 & 3 is that BSkyB fails to follow industry-standards.  BSkyB receivers cannot be used to watch industry-standard subscription services, and industry-standard receivers cannot be used to watch BSkyB broadcasts.
4	Others
There are other FTA and subscription services available on other satellites.  Many subscription services are geared towards a particular country, in which you have to reside to get a viewing card  -  a major source of irritation for ex-patriots.
These services can be received in the UK by aligning a dish permanently on to the other sat at the cost of losing access to the majority of UK targeted channels which are on 28.2E, or by having a more expensive steerable dish with a receiver that can control it, or if the sats are close enough together by modifying the receiver arm in a fixed dish so that multiple Low Noise Blocks can be mounted to receive signals from multiple satellites using a fixed dish.
Note:  Although analogue satellite, like analogue terrestrial, is becoming obsolete, other sats may broadcast all analogue, all digital, or commonly a mixture.  A twin-tuner receiver would be required to receive both  -  analogue tuners can't receive digital broadcasts and vice versa.
High-Definition (HD)
High Definition (HD) is a new broadcast standard of higher resolution than Standard Definition, requiring completely new equipment throughout from camera to television.  For the consumer this means replacing TV & STB.  When buying new kit, you should ensure that it can both receive and display broadcasts in the following resolutions:
Name	Tag	Specification	
SD	576i	720 x 576 interlaced + stereo sound	
HD	1080i	1920 x 1080 interlaced (sadly, should have been progressive) + Dolby 5.1 surround sound	
In the UK, a limited choice of HD programmes has been available via satellite and cable for some time  -  some flagship BBC programmes such as 'Planet Earth' and 'Wimbledon', some ITV programmes, and from Sky and Virgin packages.  HD from the four main terrestrial broadcasters will start to broadcast on Freeview from December 2009 with Digital Switch Over (DSO).
HD WARNINGS  -  The HD Ready stickers on TVs for sale have been much criticised in knowledgeable circles, as they mean merely that the TV can display HD video.  Note that:
1.	Many HD TVs sold to date have only SD terrestrial (Freeview) or satellite (Freesat) tuners, and to display broadcast HD require a further HD STB connected via HDMI.  With HD available via satellite and imminent via terrestrial, it's probably worth holding out for HD tuners.
2.	Many HD TVs can only display HD video by downgrading it to a lower resolution than that received.  Check that the actual, numerical figures for the resolutions supported include at least the above, preferably 1080p (1920 × 1080 progressive), as that is the format supported by Blu-Ray and the PlayStation 3 and Xbox 360 games consoles.
Analogue vs Digital
Analogue and digital TV have functional and behavioural differences:
•	A digital Electronic Programme Guide (EPG) not only gives an on screen schedule, but can also be used further to control the equipment, such as setting a PVR to record.
•	More digital channels fit into the available bandwidth, giving greater choice, but this is a double-edged sword  -  both technically and artistically, more very easily becomes less ...
•	It works quite well in sports coverage where one or both of the extra channels might:
•	Cover full matches when mainstream programmes can only show highlights;
•	In events like the Olympics, give you a greater choice of disciplines to watch;
•	In Wimbledon, give you a choice of other matches to watch;
•	Allow coverage of overrunning events without disrupting mainstream schedules.
•	However, each of us has a limit on the hours in a day we spend watching TV, so the remaining programmes not watched represent wasted resources that could have been used to make more and better programmes of a type we would have wanted to watch.
We might prefer 10 channels free from compression artefacts, showing well-made, decent, thoughtful content to 20 over-compressed channels showing shopping, repeats, lifestyle trivia, badly-made soaps, and toe-curlingly unreal Reality TV.
They also differ in the way they react to poor signal quality and interference,  particularly so with terrestrial reception  -  satellite reception is usually either there or not, because usually you can mount a dish somewhere on your property to 'see' the satellite or you can't, and, as the dish points at the sky, it won't usually collect much interference originating from the ground.
•	On analogue, a poor signal may result in a watchable channel, particularly if content doesn't require a quality picture, for example, news.  However, a poor signal in digital may mean that nothing is received, or as signal quality fluctuates around a threshold value there may be good reception for a few seconds, then nothing for a few seconds.
•	'Impulse' interference, as caused by old central-heating thermostats, on analogue may results in snow and buzzing for a few seconds, but on digital may result in overly dramatic picture break up and 'gunfire' on audio, even temporary complete loss of signal.  Such interference is difficult to cure if it doesn't originate from within your property.
•	'Cross-modulation' interference, such as that from TETRA radio communications, on analogue might cause 'tyre marks' over the picture, but on digital, depending on the relative levels of the signal and the interference, may be completely unnoticeable or result in complete loss of signal.  If the aerial system is adequate apart from this problem, then this type of interference is easy and cheap to cure, but encountering such a problem is a cue to check over the system to see if anything else can be easily and cheaply improved.
Personal Video Recorders (PVRs)
PVRs use hard disks rather than tape to record programmes.  The major differences are:
•	'Random Access' as opposed to 'Serial Access'  -  Depending in practice on how well the manufacturer has implemented it, in principle this should allow:
•	Change which recording you are watching without ferreting around for tapes;
•	Jump almost instantly to any time in a recording without waiting for a tape to wind;
•	Set jump bookmarks in a programme, for example to mark the end of advert breaks;
•	Record one programme while playing back another;
•	Live Pause  -  If unexpectedly interrupted watching a programme, a button on the remote starts recording so that later you can return to watch from where you left.
•	Setting up recordings directly from the EPG is easier than keying in the times manually.
•	Steady freeze frame.
•	Some models can monitor what you record and make 'intelligent' decisions to record other similar material that you might want to watch.
•	Most directly record the digital broadcast signal, so there are no decoding/reencoding losses.
•	You can always buy more tapes when you fill them all up, but when a hard disk is full, it's full; you have to delete something before you can record any more.  Consequently, you may want a means of copying recordings that you want to keep to an external DVD-Recorder or VCR.
A good PVR can change the way you watch / listen to certain TV / Radio programmes.  For example, I almost never anymore watch or listen to live, but instead watch a recording of ...
Promenade concerts	I skip the pretentious drivel and just listen to the music;
Programmes like Later ...	I skip over acts I don't like;
Programmes with commercial breaks	I skip over the ads;
Magazine programmes	I watch or listen to just the articles that interest me;
Summary of Non-Subscription Options
Approx starting prices inc VAT + delivery, 2007	DTT/Freeview	Satellite FTA/Freesat	Freesat from Sky
(formerly FreeToView)	
Pros	•	Five channel set
•	Cheap if existing aerial
•	Can DIY	•	HD
•	Less prone to interference
•	Cheap if existing dish
•	Can DIY	•	Five channel set
•	Less prone to interference	
Cons	•	No HD yet
•	Prone to interference in built-up areas
•	Most prone to over-compression	•	No Five channel set	•	No HD
•	Relatively expensive
•	Non-industry standard
•	No DIY	
STB	£30	£60	£150	
PVR STB	£140	£180	(sub only)	
HD STB	na	£180	(sub only)	
HD PVR STB	na	?	(sub only)	
Aerial / Dish Install	•	DIY from about £60
•	Get quote from CAI installer	•	DIY from about £75
(occasional Lidl offers £60)
•	Get quote from CAI installer	(included)