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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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Tuesday, 13 September 2011
5:20 PM

hi, jb38
my sky has 1 scart, i hdmi and red white and yellow socket on the back witch are outputs. so i just have the hdmi running to tv from sky and use the red and white for audio to the hifi, my tv is a fohen and hirsch witch is not a very popular make but not a bad lcd tv. there seems to be no audio output on the tv and i have checked the instructions

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mark's 5 posts GB flag
5:33 PM

sorry its a foehn and hirsch FH-37LMH hers what connections i have on the back
6. S-video
7. SCART 1
8. SCART 2

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mark's 5 posts GB flag
KB Aerials Sheffield

6:16 PM

mark does your amplifier have optical input?

if so use the spdif output to output the audio to your amp
if it doesnt you could convert the audio to the red and white type input using one of these…lers

now that was a quick google i have never used one and im sure many makes are availble


ps check if the spdif is an output usually you can see it lit up red behind the cover (S201EG)

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KB Aerials Sheffield's 274 posts GB flag
Wednesday, 14 September 2011
2:48 AM

amp dosnt have spdf m8,what ive actually managed to do to get the xbox to work on the hifi is use these XBOX 360 HDMI AV CABLE+OPTICAL RCA ADAPTER: Electronics but there is only 1 off each red and white plugs on the hifi so im not able to plug the sky 1 in at the same time and its a right kurfuffel getting to the back and changing them all the time. does any1 know if i can get a 2 in to 1 for the red and white audio cables, or anything else i could do. dont really want to start splitting and joining cables. i cant belive a £350 tv dosnt have an audio out and my £30 rubbish tv does.

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mark's 5 posts GB flag

8:15 AM

mark: You must just need a switch?
FourWay Stereo Audio Switch Box : AV Splitters Switchers : Maplin
for example.

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Briantist's 38,905 posts GB flag
lan from notts

8:44 AM

just a thought but sometimes scart 2 acts as in/out on some devices, long shot tho

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lan from notts's 253 posts GB flag
lan's: mapL's Freeview map terrainL's terrain plot wavesL's frequency data L's Freeview Detailed Coverage
Thursday, 15 September 2011
8:18 AM

ive been told somewhere else that i can get a scart that goes to audio leads with a in and output switch so going to try 1 off those, thanks for the help guys

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mark's 5 posts GB flag
Mary Beecham
12:52 PM

I have a freeview set top box connected to my tv and VCR via scart leads and aerial leads as per the instructions. However, I can't get a good signal on the VCR when I record and it is in black & white. Do I have to retune it or anything? It is an old VCR.

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Mary Beecham's 1 post GB flag
2:50 PM


We have an LG 42LF20FR which was bought in Dubai. It has no freeview software so we will be using it as a monitor. (this is instead of our old analogue tv).

It has two HDMI sockets to which we need to connect our Sony DVD recorder which has HDMI connection.

We also need to connect our Thomson freesat box which does not have an HDMI connection. It has an RS232 connection.

Currently the sony dvd recorder and the freesat are connected to each other by scart leads. both are then connected to the current tv also by scart leads.

My question is how do we connect the freesat box to the lg tv's hdmi connection? Also can the freesat and the sony remain connected to each other by scart leads when connecte to the lgtv?

Sorry if it seems obvious, but I really have no idea!!!

Your input would be gratefully received!!

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Debs's 1 post GB flag

5:23 PM

mark: These type of leads are generally available from places like "Pound shops", so if it doesn't work then you aren't really losing much.

I couldn't find the exact manual for your set, but I did manage to have a look at the one for the "G" model, however as was half expected it didn't give any details on the scart socket facilities as far as whether they were purely input, or input / output sockets, this facility being essential for the type of lead you are looking for to work.

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jb38's 7,179 posts GB flag
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