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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.

Help with Television sets?
Why are all TVs on sale not digital?1
Do I still have to pay for a TV licence?2
I had perfect channel 5 reception - until I got a digital TV box!3
I Have a Pocket Tv For taking out so I can keep up with news and sport. Will thi4
The pictures from my digital box are all green!5
In this section
Loft aerials1
Do I need to buy a booster?2
How to receive Freeview on your PC3
Indoor aerials4
Whole house digital TV5
Now and Next6

Friday, 12 August 2011
KB Aerials Sheffield

8:07 PM

JO Barks
try altering the output of the dvd player - sounds like its set to S VIDEO try changing it to cvbs or rgb

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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, 15 August 2011
3:22 PM

I have a regular tv, a couple of months old, which I was using with a standard aerial at my previous house-no problems picking up digital programmes
I have now moved house & the only aerials are sky ones. I have been told that I now need to run my tv through a sky box. I do not want sky, as I barely watch tv, but do have an old sky plus box.
So, I have put a sky aerial into that, connected the box to my tv with a conventional aerial & also scart connector- did a search for programmes, but it is still not sorted. Have you got any suggestions as what else I need to do?
Thank you

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Carrie's 1 post JE flag

4:52 PM

Carrie: Knowing your location would have been of assistance, as being told that you have to use a Sky box with your TV could indicate that you are in an area where Freeview reception is not possible.

If when saying Sky aerials you are really meaning a Sky dish? if so then you can use this with an old Sky box perfectly OK without subscribing to Sky, its really a question of whether or not the Sky dish is still connected, to check this, on the Sky remote press - services - 4 - 6 and observe if the signal / quality indicators are showing about 75% or so, however if not indicating at all then the Sky boxes connection to the dish could be defective, or that the dish is not aligned correctly. (or the Sky box is defective!)

Anyway if you give an update of your location (post code preferable) then a Freeview reception check can be made.

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jb38's 7,179 posts GB flag
kB Aerials Sheffield

7:38 PM

Carrie - as you seem to be connected to a sky dish doing a search on the tv will get you no channels

the sky dish screws into the tuner input and does not connect to the aerial input

by connecting the sky dish to the tuner input you can then change channel using the sky remote as long as the dish is lined up correctley of course

if there are some channels missing a card for "freesat from Sky " can be purchased from sky at a cost od £20 - u may already have a sky card in your sky box that will work so thats a step you dont need to worry about

I have used this number in the past to order a freesat card

02077053000 but sky constantly change their numbers you could also try 08706061111

Keith KB Aerials Sheffield

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kB Aerials Sheffield's 274 posts GB flag
Wednesday, 17 August 2011
12:05 PM

Hi iwonder if you can help me first off i am living in Ireland in case of different set ups. i just purchased a samsung le 40d550k1w TV.the picture from the sky box is very cloudy /specy compared to the preinstalled channels and picture on previous telly.there is no hdmi conn on my sky box how can get a better picture please

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COLIN RICHARDS's 1 post IE flag
KB Aerials Sheffield

5:28 PM

Try altering the scart output from cvbs to RGB


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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
Saturday, 20 August 2011
3:27 PM

Just move temporary into a house for 3 months, & purchased BT vision, dropped my sky. Only to find new house as no aerial!!! I have manage to get BT vision working independently via a HDMI & for now I can get free view via my sky box & i can play DVDs via my DVD player, but i want to be able to recorded free view from my DVD player, but it doesnt seem to be connecting to the sky box... when i move back home i have a aerial so i can set up the BT vision correctly, really there are that many cables floating around ... I am losing the will to live..Help...please..

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Tony's 1 post GB flag
kB Aerials Sheffield

9:30 PM

tony I assume that your dvd player is a Recorder

Connect the av1 of the dvd player to the vcr input of the sky box

The sky box from the TV scart to the tv (im assuming its not a HD sky Box) - if so then use the HDMi output to the tv

By selecting AV1 on the DVD recorder you should be able to record whatever is on the sky box at the time of recording

If you change the channel on the sky box whilst recording then the dvd will record whatever you change it too

You cant watch and record 2 different things

If you want ot do this and the input from the dish has 2 connectors (for sky plus or SKY Hd then you could go buy a cheap freesat box for £30 from Argos you could then use the sky box for recording and the freesat for viewing

--- you would use one cable from the dish to each of the sky/freesat boxes


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kB Aerials Sheffield's 274 posts GB flag
Wednesday, 24 August 2011
Pete Rostron
10:57 PM

Hi I dont know if anyone out there can help me, Im tearing my hair out. I have a JVC 47" LCD TV (I dont know the actual model because its hanging on the wall and the model number is around the back!) This tv has all kinds of connections at the back, Ill list the ones that are working
HDMI 1...connected PS3 and XBOX360 via splitter
HDMI 2...Sky+ box
there are a lot of other input points as would be expected from a modern TV including 2 scart, composite video/sound and a PC connection. The problem Im having is with the PC connection. This is a VGA socket on the back of the tv, Ive had a laptop plugged in to this on many occasions and it has worked fine, however I decided to plug my PC into it after I dropped my monitor and cracked it, and thats when the problems started!! I purchased a brand new VGA cable from Maplins, and connected everything up. I booted up the pc and as normal the pc notified me of its make etc in the boot up sequence It then told me (as usual) that windows was starting up...Then nothing...Not a thing. I borrowd a monitor and checked the pc and its working fine, there must still be a signal going into the tv because it remains black (Usualy goes blue without a signal). So thinking there was something wrong with the connection I purchased an SVG to Scart lead, plugged this in and absolutely nothing...and to top it all with this fitted none of my controlls would work on the tv!! the remote AND the manual controlls on the side of the TV stopped working completely. I unplugged the pc and everything again works fine. I realy do want to have my pc connected to the tv (preferably using SVG) but cant seam to get any further with it,Ive obviously tried all the usual things but it just wont show anything after the start up screen, any Ideas would be appreciated
Thanks in advance

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Pete Rostron's 2 posts GB flag
Thursday, 25 August 2011

8:37 AM

Pete Rostron: Start the laptop with the VGA cable disconnected and it should boot to your cracked screen.

Once you have logged in, press Windows+P and select "Projector Only" and the screen should transfer to the TV.

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Briantist's 38,899 posts GB flag
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