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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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Monday, 29 July 2013

6:23 PM

Rita Felipe: If you only wish to use these devices for playback purposes then an Alba 3 way scart switch box should be OK for your requirements, as this will enable you to select the device you require by simply pressing the button appropriate to the input socket used for that device.

Argos item number - 103/0017 @ £7.99.

Buy Alba 3 SCART to 1 SCART Selector at - Your Online Shop for Adaptors.

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jb38's 7,179 posts GB flag

8:04 PM

Rita: Although the SCART selector will do the job (it has to be said that such adaptors are less than ideal), its always good to have a look at the possible connections in the back of your TV and other boxes.

I now ask customers buying new TV's what they already have (if they bring in the manuals, thats a godsend!), since there is now only one scart as standard. Have a look at the back of your TV, and find out what you have in the back.

Depending on the age/model/make (if you know the make and model of your equipment, we can tell you what connections you have), your likely to also have yellow, red and white ports called RCA's or phonos. A cheap adapter and cables will allow them to connect your TV to a DVD/video/recorder.

Of course if both your TV and another box both have HDMI's, then a cable to connect them would be better than scart anyway.

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MikeB's 2,579 posts GB flag
Thursday, 1 August 2013
4:19 PM

Mike & Brian : thanks VV Much for all your helpful info here. The 2 channel sound from the Samsung is excellent through the Sony speakers - definately a more powerful step-up.

Dont the tuners work off old analog signal information - and since everyones digital these days, all those channels would be blank?

With switchers, i have to keep in mind integrating my multiregion player & Xbox (both original and 360) - at the moment, they're working well off the speakers.

An interesting aside, though - my ipod Nano and Composite AV , which output signal the Panasonic could read off AV3, is now soundless. Running the ipod through the AV on the Samsung sorts out the sound, but the Panasonic does not record the Samsung output, just the TV signal (on AV2). Do i need a further Scart switcher to rectify this?

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Tarquin's 2 posts GB flag
Sunday, 4 August 2013
raymond west
2:22 PM

Now that Sky has removed the Autoview function does that mean that the only solution to select a future programme, and have the box switch to that channel,is to have a twin tuner (HDD box)? Does this solve the problem of (say) Wimbledon when BBC1 start the broadcast but the switch to BBC2 mid afternoon. I want to be able to programme all of this and have the box switch over in my absence. There is no clear info on this.

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raymond west's 1 post FR flag
5:49 PM

we have not been to our cottage for 6 months and the tv reception has deteriorated. We have a sky dish connected to a humax satellite receiver which used to work fine but now its hopeless losing signal every five minutes. It says our postcode cannot be found. Any ideas?

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sr's 1 post GB flag
sr's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage

7:09 PM

sr: If the box only has a problem recognising the post code then try another one from somewhere within a mile or so away, as the post code is only required to enable you to view the correct regional programmes for the area you reside in, as a matter of fact you can enter a post code for anywhere in the UK and the box will respond as though you resided there.

But as far as losing a signal is concerned, are there any trees etc obstructing the dishes view of the S/SE skyline? if not then there is a possibility that water has gained access to the "F" connector screwed into the dishes LNB port, if the Humax is a PVR with twin inputs try swapping them over and see if anything changes.

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jb38's 7,179 posts GB flag
Wednesday, 21 August 2013
1:39 PM

Hi Brian,
Is there a way to connect my Samsung DVD recorder (BD-F8900M) to my Sky HD box. There is no scart socket on the dvd recorder. I would like to copy to dvd. Thanks.

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Paul's 1 post GB flag
Monday, 26 August 2013
roger willoughby
8:40 PM

i have a new logic 24" tv connected to our virgin box however I cannot get a full screen showing is there a simple answer to this?

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roger willoughby's 1 post GB flag

9:37 PM

roger willoughby: You should try going back into the set up procedure and and look for anything referring to "picture" or "screen" and check that widescreen is selected.

You should also check that similar is selected on the Virgin box, should that be adjustable on your particular version of V box!

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jb38's 7,179 posts GB flag
Wednesday, 28 August 2013
john bartlett
1:13 AM

Can I connect my Bush digital record to my Toshiba TV SIMPLY using Scart out of Bush and VGA into Toshiba ? (my old TV had a Scart port so I successfully used scart to scart, but new TV Toshiba doesn't have a scart port, only HDMI USB and VGA).

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john bartlett's 3 posts TH flag
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