Digital TV

From DIYWiki
Jump to navigation Jump to search

000932pv satdish-2.jpg


TV in the UK has gone "digital". Since the end of 2012 all analogue TV broadcast systems were shut down, and the only way to receive broadcast television in the UK now, is via one of the various digital TV platforms.

This article outlines some of the ways you can receive digital TV

Ways to receive Digital TV

There are four primary delivery systems for digital TV in the UK. These are:

  1. Digital Terrestrial Broadcast (sometimes called Freeview)
  2. Digital Satellite Broadcast
  3. Cable TV
  4. Internet streaming and download

Available hardware choices include:

Integrated Digital TV / SMART TVs

New TVs now incorporate one or more digital TV tuners. Typically a terrestrial digital tuners (aka DVBT (Freeview) or DVBT2 (Freeview HD) and quite often a DVBS digital satellite TV tuner. These receive digital from an existing house TV aerial or satellite dish.

Many TVs are now classed as "SMART" TVs - this basically means they also include a computer preloaded with software for access to streaming services directly without the need for any external boxes or adaptors.

Take care when buying second hand HD TVs since not all HD TVs also include a HD compatible tuner. Hence they will only be able to display HD pictures when fed from an external source - all programs received on the internal tuner will be standard definition. Look for a technical specification to see if it has a DVBT2 tuner.

Set top box

A set top box (STB) is a generic term for any external box that decodes a digital TV service (from a conventional TV aerial, a satellite dish, or a digital cable service) and allows it to be displayed on your TV. The box is typically connected to the TV by either a SCART lead or a HDMI lead (and on rare occasions by a co-ax). Most of the Standard Definition (SD) converter boxes have a SCART output, and High Definition (HD) ones will typically also have a HDMI connection.

SMART TV dongles

There are many external plug in devices or "dongles" that allow SMART TV facilities to be added to any TV and many computer monitors. Typical examples include Amazon's "Fire" TV stick, and Google "Chromecast". These devices can also be used to "upgrade" older SMART TVs that perform poorly due to not being able to support modern streaming apps, or due to lower than ideal processing power.

Personal Video Recorder

Personal Video Recorders or PVRs are more sophisticated set top boxes that are also able to record programmes. Programmes are usually recorded onto an internal hard drive - with a typical entry level recorder containing enough hard drive space for several hundred hours of recording capacity. Unlike video tapes or DVDs, a PVR can usually perform a number of playback tricks that were not previously possible, such as watching a recording from the start before it has actually finished recording - so called "chase play", pausing and rewinding a live broadcast etc.

The better boxes have twin tuners to allow recording of a different program to the one being watched or recording two different programs at once. The most sophisticated boxes offer advanced features like USB or Ethernet interfaces to allow connection to a computer or network.

Many modern TVs also have a primitive PVR capability built in that will allow them to record a program to a USB connected storage device like a hard drive or flash drive. (Note that these may have quite severe limitations such as not being able to watch a different channel to that which is being recorded). Also the stored files are typically restricted to only working on the TV that made the recording.

Games console

Many games consoles can also make very good video streaming platforms - able to play content taken directly from the internet, or from local servers and hard drives on your own network.

The Internet

Another digital TV source is the internet. This can be accessed by computer and a growing number of games consoles and other media devices.

What's available:

  • BBC iPlayer: plays a selection of the most popular programs on demand, up to 7 days after airing. Plus it allows you to catch up on previous episodes of a series during the duration of the series being shown.
  • ITV, Channel 4, and 5 also have a similar service.
  • Commercial streaming services like Amazon Prime, Netflix, Disney+ etc. Make substantial amounts of programming available to subscribers. Sky TV subscribers also have access to similar capabilities.
  • Some internet service providers (notably BT and Virgin) have TV content streaming packages as well.
  • Various video viewing sites, eg youtube, google, allow viewing of user created video footage (and large swathes of unlicensed commercial content that has been illegally uploaded!)
  • P2P file sharing sites allow the (typically illegal) download of TV and movie content from around the world.
  • Masses of instructional videos on numerous sites, covering pretty much any subject you can think of.

Some of the main channel sites also allow "live" viewing of at least some of the content. (note that UK residents will require a TV license if using computer equipment to view or record live TV in this way)

To watch much TV over the internet uses lots of data, so avoid Internet Service Providers that place a cap on the amount of data downloaded. It also requires a connection that is fast enough to stream reliably. Most streaming services will adjust the quality of the video delivered to get the best experience possible with the available speed.

Approximate internet speeds required to watch streaming video
Service / Platform Minimum for SD Minimum for HD Minimum for Ultra HD/4K
Youtube 0.7 Mbps 2.5 / 5 Mbps 20 Mbps
iPlayer 1.5 Mbps 2.8 Mbps n/a
Amazon Prime 1 Mbps 5 Mbps 25 Mbps
Disney+ 0.7 Mbps 5 Mbps 25 Mbps
Netflix 3 Mbps 5 Mbps 25 Mbps

* Notes:

  1. Youtube can serve lower resolution SD content on slow connections, and intermediate resolution 720p HD content at a lower data rate than full 1080p HD content.
  2. All the platforms may stream different rates to different types of device, so watching via your tablet or phone on the wifi may not use the same data rate as in your web browser on the computer of on your smart TV

Digital TV Performance

Performance of broadcast digital TVs in poor signal conditions is different to that of analogue. Where an analogue TV will suffer a progressively degrading picture (becoming ever more "snowy"), a digital picture will remain "perfect" until close to the minimum signal level, and then will begin to experience serious errors and glitches followed by complete loss of picture shortly afterwards. This is known as the digital "cliff effect".

This is most noticeable with the freeview DTV service, where an existing aerial installation is reused. A signal that may have resulted in a slightly grainy (but watchable if you are not too fussy) analogue picture, may not provide an acceptable DTV service.

Performance of Internet based services can vary greatly - from very poor to fairly good for real time streamed services, and poor to excellent for downlaoded services. Most online TV is only viable with a broadband connection offering at least 1 Mbps or better download speeds, although you will need at least 5MB/sec for the higher quality streaming sessions.

Consumer Test Reports

The government has commissioned Ricability, an independent consumer research organisation to provide consumer test reports on a range of Digital TV products, including aerials, set top boxes, DTV recorders and integrated TVs. Their results can be found here.

Content providers


With freeview STBs or IDTVs, you buy the box/tv, but there are no ongoing costs, no contract, no subscription. You just plug it in to an aerial and watch.

Freeview and other DTV details


A free satellite service offering a range of channels including some High Definition (HD) ones (assuming you have the right equipment). You will need to purchase the relevant Freesat STB or Freesat PVR, and possibly pay for a dish to be installed, however there is no ongoing charge.

Freesat details


Offer various pay per month and pay per view channels and programs. They also offer HD content on some channels (at extra cost)

Sky Details

Freesat from Sky

Not to be confused with Freesat described above!

You can purchase a complete Freesat from Sky installation package for a fixed price. This can be an attractive way of getting the hardware required (dish and STB) and the installation carried out as a bundled deal with no ongoing costs. You can also purchase a "Freesat from Sky" decoder card on its own for use in and existing Sky STB. Friends and relatives who have upgraded from ordinary Sky to Sky+ (i.e. a Sky twin tuner PVR), may have a "spare" ordinary Sky box you could borrow.

In addition to the Freesat from Sky option, you can also use any Sky STB without any decoder card in it. This will let you see all the Free to Air channels, but not handful of additional the Free to View ones you get with a decoder card.

Note if you initially subscribe to a Sky paid for service, and then stop, your existing decoder card should enable you to continue to watch all the Freesat from Sky content, including the free to view channels.

Freesat from Sky Details

About Free to View and Free to Air

Satellite services such as sky's typically include some channels that can be viewed on any suitable satellite receiver with no need for a subscription, or any form of decoder card. These are known as Free to Air services.

However there are also what are known as Free to View services. These require no subscription, but are encrypted and hence can't be viewed without a decoder card.

For details of which channels are included in which packages, along with which are free to air and free to view, see this list on wikipedia


Pay per month and pay per view cable service, choice of packages with different channels included, and differing prices. Some customers can get cable TV at no extra cost if they also have other services from Virgin.

Pay per view content is also on all packages. This is PIN protected to prevent misuse, but the PIN code is crackable by very determined kids. The PIN can be changed any time.

Virgin Cable Details


Another option (probably more for the TV enthusiasts, or people in search of specialist/foreign language programming), is to purchase generic digital satellite equipment. If having done this, you align the dish on the 28.2E˚ Eurobird Satellite Cluster (the one that carries the Sky and Freesat programming) you will in essence have something similar to Freesat as described above (although without the Freesat electronic program guide which makes finding out what is on far simpler). However there are other satellites that you can also "see" from the UK that are intended to provide programming to mainland Europe.

See Also