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Connecting it all up

Why are there so many sorts of connecting cables? Find out with this quick guide.

Why are there so many sorts of connecting cables?  Find out wit
published on UK Free TV

Why are there so many sorts of connecting cables? Find out with this quick guide.

The connectors on each cable are called plugs (and are also called male) and they will usually fit only into one sort of socket (or female connector).

Most cables you will come across are male to male. Occasionally you will find leads with a socket on one end and a plug on the other, and these are called "extension cables".


The SCART cable is used to connect a set-top box to a television set, or to a video recorder. This can only be a short cable. The SCART cable carries all of these types of signal:

  • analogue stereo sound
  • a single RGB television picture
  • a single composite video picture
  • a single S-Video video picture
  • widescreen picture signal

As stereo sound, RGB picture and widescreen signal is the best possible combination for digital television viewing, it is vital to use a SCART lead between any set-top box and the main television.

The composite video picture with stereo sound is the best combination for a VHS video recorder. If your set-top box has two SCART sockets, it is likely that the one marked TV will carry RGB picture information and the other will not.

If your television has more than one SCART input, you may need to choose a special one (marked RGB) if you want to use RGB from the SCART cable.

On most set-top boxes it is possible to turn the RGB output on and off. This can be used to test the RGB input function on the television ? the picture quality appears blurred when it is disabled.

If have a DVD player, rather than a VHS recorder, you can attach this to the set-top boxes second SCART connector. The signal from the set-top box will normally be overridden by the DVD player when it is on, usually in high-quality RGB.

Some very cheap SCART cables do not have all the pins connected. They may not provide RGB and widescreen picture signals. SCART cables are normally no more than three metres in length.

UHF lead

The UHF lead is a lead that you would traditionally associate with television signals. They can carry:

  • up to 45 (but normally only five) analogue television channels
  • a single picture from a set-top box
  • around 50 analogue cable TV channels
  • mono sound
  • NICAM stereo sound
  • Teletext services (for example, Ceefax)

You can't avoid these cables if you are going to use Freeview, as these cables are the only ones that you can use to distribute Freeview signals around the house.

Where you have an integrated digital television (an idTV) you just need to get the signal from the aerial to the television with one of these cables.

If you are using a Freeview set-top box, you will need to get the signal from the aerial to the set-top box using this aerial lead, but for best results connect the TV to the box with a SCART cable.

You can also use a UHF lead to connect a set-top box to a television somewhere in the house. Your set-top box will require a RF (radio frequency) modulator. Note that "RF passthough" is another way of saying there is no modulator. You will be able to "tune" the second television into the picture showing on the set-top box.

Some boxes (all Sky boxes) have the ability to connect a remote control receiver to the second TV end of the interconnecting cable, so you can change channels.

The set-top boxes, whilst providing a reasonable quality picture to the second TV, will always provide only mono sound via a UHF lead.

The step-change in picture quality obtained by switching to RGB on a SCART is far greater than any obtained though spending any more on a gold-plated SCART cable.

Satellite or cable TV cable

These cables are usually very stiff, and have a very basic screw connector on the end. Usually they will provide an unbroken link to the satellite dish. At the dish end they plug into the device on the end of the arm, the LNB.

Don't try to disconnect these cables when the set-top box is on. Usually there is a small voltage that will cause dangerous sparks.

If the cable connects to a satellite dish, there is not much you can do with the cable. Each receiver in the set-top box needs it's own wire to the LNB. With a personal video recorder (such as Sky+), or a multi-room installations there are two cables to the four-output LNB on the dish. If you want more rooms, each will require it's own cable.

If the cable is providing cable TV, then it is possible to use inexpensive "Y connectors" to link the incoming signal to various set-top boxes, cable modems, or - via an adaptor - directly to the back of a TV.

Composite video cable

This is the most simple and basic video connection you can get. It carries:

  • a single picture from a set-top box

The picture will be in colour, and of comparable quality to a analogue broadcast station. However, there is no sound. For that reason this cable is often found joined to a stereo audio cable.

These signals are quite robust and can be carried for many metres. Often modern television sets have a single yellow photo input on their front input panel.

You also use an identical cable to carry digital stereo (SPDIF) sound.

Stereo audio cable

These cables carry the left and right channels of sound on two joined cables. They are usually required when a SCART cable is not being used, as the SCART cable already carries stereo sound.

If you are connecting your set-top box to an external stereo system, a separate stereo audio is used.

There is no real practicable limit to the length of these cables, but excessive length will degrade the quality of the signal.

S-video cable

The S-video standard is not well supported by most UK digital TV boxes, and very few have a S-video socket. If you need one for a particular analogue camcorder, use it, but avoid S-video with digital television. If you are using what appears to be a monochrome picture from a SCART lead, it will certainly by an incomplete S-Video signal and you should change to the RGB input.

VGA cable

This is the cable you will use to connect a computer to a old style monitor, and some modern LCD screen too. Most modern LCD TVs will have a VGA input too.

If you want to connect a set-top box to a LCD monitor, you can buy a conversion box from around 60. However this will not result in a better picture than using an existing SCART socket if there is one.

The only way to get higher than normal television resolution is to use a VGA in conjunction with a personal computer or modern games console.

DVI cable

If you want to get the very best out of a television or monitor use a digital video interconnect (DVI) cable.

This will be the only way for most televisions and monitors to receive high-definition pictures from a computer, and some set-top boxes.

If you can use either a VGA cable or a DVI cable, choose the DVI option.

HDMI cable

If you want to get the very best out of a television use a HDMI cable.

This will be the only way for most televisions to receive high-definition pictures from set-top boxes.

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Wednesday, 17 April 2013

3:34 PM

Ray123: The TV only requires one input because its not capable of recording, any satellite (and only satellite) device that enables you to record one channel whilst viewing another is always fitted with twin tuners hence the requirement for two inputs.

By the way the LNB2 input on a Sky box is mainly used for recording purposes, normal viewing being via the LNB1 input.

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jb38's 7,179 posts GB flag
Sunday, 28 April 2013
10:41 PM

Hi there,
I thinking of leaving VirginMedia for TalkTalk. If I have the phone+broadband, could i buy my own PVR + power line adaptors or would I have to have their Youview setup?
thank you.

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Ruth's 2 posts GB flag
Tuesday, 30 April 2013
ian from notts

7:02 AM

Ruth- You can just have TalkTalk's broadband set up and buy your own PVR with built in smart if you wish.
Youview also sell their PVR without a company subscription if thats what your after

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ian from notts's 253 posts GB flag
ian's: mapI's Freeview map terrainI's terrain plot wavesI's frequency data I's Freeview Detailed Coverage
Sunday, 9 June 2013
6:53 PM

John H: Just purchased a hdi DVD player with no scarfs outputs just needs a hdmi cable we have virgin media does the hdmi cable go into the tv or into the TiVo box have tried both bit nothing is working can't even get the DVD player to come on

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Christine's 1 post GB flag

9:12 PM

Christine: By Hdi DVD player do you mean a blu-ray player? Blu-ray players do not have scarts - they have to use hdmi cables (which are actually very cheap now).

Many DVD players (or most of the remaining DVD players on the market) also just use HDMI only as well. Tivo boxes apparently have both HDMI and scart. More about the different connections are at the top of the page.

Firstly, is your TV HD Ready? If it is an old style CRT (deep) TV, then you will have no HDMI imputs at all, and your going to either return the player or replace the TV. However, assuming you have a flat HD ready TV, you should have at least one HDMI imput.

If you look at the TV's manual, it will tell you where to put the HDMI cable from the Blu-ray player. It will normally go in HDMI 2 on the TV, and the Tivo box will use HDMI 1 (you'll being using that one more). Make sure the HDMI cables are connected properly (do not force them) from the player to the TV, and make sure the player is plugged in. Switch it on.

Press the 'source' button on your TV and you should scroll through from the TV's own tuner, then the Tivo box, and then the blu-ray. The player will now often go on the net, so follow the instructions to set that up if you want.

If you have huge problems, tell us the model and make of player/tv, but the instructions for the blu-ray should tell you everything you should need to know.

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MikeB's 2,579 posts GB flag
MikeB's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
Wednesday, 24 July 2013
12:24 AM

Evening/Morning all, you helpful people. Maybe you might be able to help me out with some old school Non-HDMI connections.

My freeview box comes in (through boosters and switches) to a Panasonic HDD DMR-EX769. This is Scarted to a Samsung Plasma P42D4S with NO side speakers (I know , very helpful), so am hoping to run the sound through my Sony STR-DG700 6.1 amp.

Have various Phono and RGB cables, plus a digital optical cable between the HDD and the amp.
Have tried many different cable arrangements and settings , but cannot get 2 channel or 5.1 out of the speakers (which are wired up to spec).
Any thoughts?
Many thanks

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Tarquin's 2 posts GB flag

8:54 AM

Tarquin: The Panasonic DMR-EX769 has no Freeview HD capabilities, so the best you are going to get out of it is a stereo feed.

The "Dolby Surround" (compare "Dolby Digital") system is a way of encoding a back-effect-channel and a dialogue-channel into a conventional stereo signal.

If you are watching a live (or recorded) show that is in "Dolby Surround" - which is going to be a US-made one from the 1990s onwards - you set your amplifier to "Dolby Pro Logic" to get output from the surround speakers.

However, if a show is not encoded to "Dolby Surround", you will need to switch back to "direct stereo" for the best quality sound.

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Briantist's 38,899 posts GB flag

8:58 AM

For how Dolby Surround works see Dolby Surround - Wikipedia, the free encyclopedia .

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Briantist's 38,899 posts GB flag

10:15 AM

Tarquin: Brianist got in first with regard to what sort of sound quality your going to get, but I'd go back to first principles with your setup.

The Panasonic has a Freeview tuner (although a good five years old, the last of the line has only just been delisted). Your Samsung is rather old (2005) , and the best I can make out has:

2 SCART connectors
1 Component (YUV)
1 S-Video connector (Mini DIN)
1 Digital RGB (DVI) HDCP compatible
1 Analog RGB (PC)
1 AV connection

and possibly a freeview tuner....(it had a tuner in the german version)

If it does, then use both the tuner in the PVR and the TV seperately (pass through or split, the choice is yours). If your using a seperate Freeview box when you have one in the TV, etc, you don't need it, unless the TV's tuner is simply unusuable.

I'm surprised there is no HDMI input, but DVI was used at the time by one or two other brands as well (although Samsung is normally in the lead on these things, so I would have guessed HDMI, but still..).

Since you have an HDMI output on the PVR, you could use that instead of scarts, if only to allow you to use an HD source. You can get a DVI/HDMI cable for a relatively small sum…6FC, but remember that DVI does not do audio, and you'll need to use the phonos from the PVR to the Samsung for this. Perhaps stick with scarts....!

To sum up - to simplify your setup, you may no longer need your booster, and if you have working tuners in both TV and PVR, you can lose any extra Freeview boxes. Take any switches/converters etc out of the system if you can.

In the longer term, with my TV sales hat on, I'd look to upgrade the TV. You TV is actually slightly wider than an 55in LED, and you'd get 3/4 HDMI's, Full HD, Freeview HD, digital optical, full smart and built in wifi from pretty much any of the four main brands.

If you'd wish to stay at 42in (which you probably wont), the excellent LG N575 in 42in for £499 would be a good place to start for the price. I saw a 32in version next to similar specced Samsung, Sony and Panasonic models last week blow the others away when rendering the end titles of a film (white text, black background - an excellent test) - it was almost as good as a 400hz screen, which is amazing for a 100hz panel.

BTW - No TV for a fair number of years has had side speakers, although the very nice new 4K Sony 9005 does have them, but is £4000. The sound is excellent though...

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MikeB's 2,579 posts GB flag
Monday, 29 July 2013
Rita Felipe
3:09 PM

I have a virgin box(not tivo) unfortunately it only has one scart my older one had two. I need to connect my TV, DVD, and Video (only to play not to record)can you tell me what I should connect to what.


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Rita Felipe's 1 post GB flag
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