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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, 27 July 2011
3:29 PM

Briantist: Thank you for the advice. The Freeview box (which is fairly old and basic, someone gave me it for nothing) claims to record, though I haven't tried it yet. But I really want to record to DVD with my Panasonic, and only use the Freeview box to access digital signals. I'm happy to buy extra equipment if I have to, but is it, basically, possible to wire up 2 different boxes (Sky and Freeview) to one DVD recorder/TV?

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dud5ers's 6 posts GB flag
KB Aerials Sheffield

3:48 PM
Hope Valley

If you add the freeview box through the av2 of the panasonic dvd recorder you could record from the freeview box onto a dvd disc- you could watch a sky channel whilst the dvd recorder is recording - this means you could use the equipment you have without spending any cash and sending your equipment to landfill

Alternativly like Brian says you could buy a Freeview PVR which costs around £100 upwards this would enable you to watch one channel while recording another - you could in theory ditch sky especially if you dont use sky 1 movies or sport - the number of people who are paying sky because they think its the only way they can get digital is staggering!

- the freeview recorder would attach into one of the tv's 3 scart sockets

Keith KB Aerials Sheffield

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KB Aerials Sheffield's 274 posts GB flag
KB's: mapK's Freeview map terrainK's terrain plot wavesK's frequency data K's Freeview Detailed Coverage
4:23 PM

Thanks, Keith. I need Sky for the sport (well, football and cricket, not the rest). Looks like I need to get down on my knees and start playing with cables.

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dud5ers's 6 posts GB flag
KB Aerials Sheffield

5:50 PM
Hope Valley

ok dud5ers Have fun

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KB Aerials Sheffield's 274 posts GB flag
KB's: mapK's Freeview map terrainK's terrain plot wavesK's frequency data K's Freeview Detailed Coverage
Monday, 1 August 2011
5:47 PM

We have just purchased a free sat box to replace a sky box. The box only has one scart socket, together with our existing tv. How do we now connect the DVD player into the system? Satalite cable goes to free sat, scart goes from free sat to tv at present.

Help please



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nigel's 1 post GB flag
KB Aerials Sheffield

6:23 PM

you can buy scart switcher boxes fairly cheaply the sat box and the dvd player connect to the box which has a scart fly lead coming out of it in effect doubling or tripling the available scart sockets on the tv


2 Way Scart Switch Box : AV Splitters Switchers : Maplin

never used this particular product but I would imagine it would do the job


KB Aerials Sheffield 07946481125 01142514389

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KB Aerials Sheffield's 274 posts GB flag
Tuesday, 2 August 2011
katharyn bull
10:55 AM

hi we are looking at getting a samsung lcd tv le40r8.can we connect it with a hard drive as well as sky+hd box and dvd player?

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katharyn bull's 1 post GB flag

5:49 PM

katharyn bull: You have two HDMI inputs, so you can use the "second" on for a (I presume) Freeview+ or Freeview+HD box.

This is assuming your DVD player is connected to a SCART input.

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Briantist's 38,899 posts GB flag
Thursday, 11 August 2011
8:02 AM

I have just purchased a New Samsung UE406100 led tv which only has one connection for a scart lead.
The problem is that when the dvd hard drive player is on,it overrides my Sky box.
Can you tell me how to set up to avoide this happening please?

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Steve's 1 post GB flag
jo barks
8:04 PM

Hi I have got an old portable with one scart socket. I plugged a dvd player in which also has one scart socket. The picture is in black and white

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jo barks's 1 post GB flag
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