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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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Sunday, 30 January 2011
Terry H
2:27 PM

I have an analogue dvd recorder, digital TV, satellite receiver for Greek programs and a free view box. All units have 2 scarts. I can record every thing except the Greek channel. Tried changing from AV2 to AV1 but makes no difference. Can anyone advise on how to connect everything and do i need the freeview box in the system.

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Terry H's 1 post GB flag

7:55 PM

Terry H: As a digital TV is part of your set up you only require the freeview box if you want to record anything from it onto your DVD recorder otherwise its not necessary.

Regarding not being able to record the Greek channel from your (brand unknown) sat receiver, can you actually view it but just not record it? it would be of assistance if the channel in question was known.

As far as connections are concerned, the commonly used scart in / scart out procedure known as daisy chaining might not be very versatile for what you wish to achieve and so I would be inclined to use a 2 input scart selector box with a cable from each of its two input sockets running respectively to each of the two receiver boxes, (sat and freeview) with the third common lead coupled to the DVD recorder input.

That said though its difficult to advise without actually knowing what device (exc TV) is most commonly used, and if this is aspect is clarified more precise info could be supplied which may, or may not, involve the aforementioned procedure.

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jb38's 81 posts GB flag
Thursday, 10 February 2011
6:46 PM

hi i just got sky stander box conected in my house it was conected to my flat screen tv via a hdim cable but my tv broke and i got a older tv from a friend of mine.
the tv i got dos not have a hdim conection on it only a scart conection but that dos not work on it can anybody help.
thank you

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jason's 1 post IE flag

9:42 PM

jason: I'm a bit confused, a "standard Sky box" does not have an HDMI output.

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Briantist's 38,915 posts GB flag
Friday, 18 February 2011
10:59 AM

Hi I cancelled SKY a few months back and removed their box from my set up. However now I cant seem to get my dvd recorder to tune into the Freeview stations from my TV(inbuilt Freeview)If you follow the TV/recorder's set up instructions they both show the antenna going into the recorder which would seem to circumvent the TV? The result is the recorder only picks up the 5 analogue stations.Where am I going wrong?

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Pedro's 1 post GB flag

12:16 PM

Pedro: I would expect your recorder has no Freeview tuner.

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Briantist's 38,915 posts GB flag
Tuesday, 22 February 2011
9:50 PM

I have a 32in sony LCD,CONNECTED TO Panasonic
dvd, all working fine till i tried to connect bush freeview HD box today, now i can't use my recorder, Please what is the correct set up to make everything run smooth again..i have two HDMI cables and two scarts in use?

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John's 1 post GB flag
Wednesday, 23 February 2011

7:12 AM

John: Not sure why you are using any SCARTS at all. Just use HDMI to connect HD devices to your TV.

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Briantist's 38,915 posts GB flag
Thursday, 24 February 2011
2:19 PM

Hi when I had sky I was able to use the system as a booster to 2 other tv`s in the house, with humax foxsat unit i don`t seem to be able to do this now??? any ideas

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

2:45 PM

steve.s: The analogue RF output system is very out of date.

Your options are

1) use a wireless video sender;

2) add Freesat boxes to your other sets. You can get SD Freesat boxes for £30, and you just need to run in some satellite-grade cable from them to spare outputs on the dish.

The advantage of (2) is you can watch any
channel you want on each TV.

You can also get RF modulators, but for the cost you may as well have the full choice of channels.

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Briantist's 38,915 posts GB flag
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