menuMENU    UK Free TV logo Freeview



Click to see updates

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

Sunday, 7 December 2014
Neil Bell

2:52 PM

David Hobbs You mentioned before that your loop box was working with the internal tuner in your TV via SCART but was this a cable? and what was actually plugged in to the input of your loop box? Is the 3.5mm plug too big? Maplin do a 2.5mm stereo plug with a 3.5mm stereo socket on the back but I don't know if its a 2.5mm plug you need. The information I found online about your loop box didn't give any information on input sockets. Regards Neil

link to this comment
Neil Bell's 106 posts GB flag
Neil's: mapN's Freeview map terrainN's terrain plot wavesN's frequency data N's Freeview Detailed Coverage

6:47 PM

David Hobbs: I think your right - take the leads that fit into the loop box with you to Maplin (take a photo on your ohone of the input as well on the loop), and see if they have a lead with 3.5mm at one end, or at least an adapter to make it 3.5mm or RCA phono.

When I looked into the input on your loop box, it became a bit of nightmare, since its talked about using a PDA 101cable, etc. However, by blowing up this photo…jpeg , it looks like the scart adapter simply has left/right phono's at the other end. However, since you already have a lead with phono's at the other end, I assume they didn't fit. On the other hand, if its a XLR 3 pin input, then they do adapter's as well.

Neil Bell: Its no bad thing to at least know where the inputs are. Modern TV manuals seem to be more skimpy these days, and if you look through the 'Connecting it up' page, many questions have come from people who simply havn't realised that the input/outputs have changed, or dont really know how to put them together. I would normally say 'look at the manual', but if the manual is just a couple of sheets of paper with no wiring digram, then thats more difficult.

The other thing as well is that if you dont know whats on the back, its a pain when its mounted on the wall and you need 'that socket', but you can't get to it, or when you've a TV with very few HDMI sockets - there are ways around it, but its a mare. Its one reason I like to point out to customers that buying a TV with more HDMI's does cost more, but its can make your life so much easier.

link to this comment
MikeB's 2,579 posts GB flag
Monday, 8 December 2014
Neil Bell

1:09 PM

MikeB From that picture it looks as though you have to have "outreach" connections to the loop box from wall plates which can have e.g. 2 phono sockets or microphone inputs etc which would make sense in a church or public hall where someone might want to plug an alternative audio source in to the system. It all seems rather over engineered however for a domestic situation such as David Hobb's where you would expect just an audio output from TV or HIFI. On the other hand presumably these loop systems are monaural rather than stereo and so you need some way of inputting both channels without shorting them out for hearing users. We don't know for sure if David Hobb's system is the same as that but I am interested to see how he gets on!
Regards Neil

link to this comment
Neil Bell's 106 posts GB flag
Neil's: mapN's Freeview map terrainN's terrain plot wavesN's frequency data N's Freeview Detailed Coverage
David Hobbs
3:31 PM

MikeB: Hi Mike/Neil, thanks for all your help. The Induction Loop is now working on TV, PVR & BlueRay player ???? I went to Maplin's this afternoon and was able to purchase gold-plated two phono to 3.5mm adaptor plugged into headphone socket and a single phono cable plugged into the adaptor and loop box, hey presto ????am a very happy man now. Cheers mate thanks for everything and your patience.

link to this comment
David Hobbs's 13 posts GB flag
Friday, 1 May 2015
steve drury
4:21 PM

Mark Petersen: I have a Technisat 0006/4940 box, when trying to watch any HD channels I get a picture for about twenty seconds then the screen goes black but the sound stays on.
What should I do?

link to this comment
steve drury's 1 post GB flag
Monday, 8 June 2015
Miss P. Davies
12:37 PM

Hi I have bought a Blaupunkt LED Freeview TV but I have not yet been able to watch it . I can not get most channels.

I tested the aeriel socket with the short RF (M to M) aerial cable that was included in the Blaupunkt box on another smaller digital TV to test the aerial and it worked so I did not have to replace the outside aerial.

I checked to see what cable it was and it says RF cable so I ordered a 10m RF cable but it did not work.

There are so many aerial leads to choose from I can't buy any or everything . Please can you help me? All I need is the correct 10m cable from the aerial socket to the TV.

Thank you,

Miss Davies.

link to this comment
Miss P. Davies's 1 post GB flag
Dave Lindsay

1:36 PM

Miss P. Davies: Where are you? In some locations only PSB channels can be received, these being BBC TV and radio, ITV/STV/UTV (and +1), Channel 4, Channel 4+1, More4, ITV2, Channel 5 and a few others.

link to this comment
Dave Lindsay's 5,724 posts GB flag
Friday, 24 February 2017
Carole Redgrift
3:11 PM

Neil Bell:

Hi. I have a loop amplifier. It is connected to a Virgin tevo box. I have no problem. However I have added a seperated DVD player. I connected a scart to the TV. no sound comes through my hearing aid from the loop. I can only hear a channel from the TV. I cannot connect another scart to the tevo box as there is only one connecter and that is used to connect to TV. Any ideas please? Or will it mean I just cannot use a DVD player?

link to this comment
Carole Redgrift's 2 posts GB flag
Neil Bell

7:19 PM

Carole I'm guessing here. Have you connected your loop amplifier to the SCART output on the Tivo box rather than the TV? If so maybe you are hearing a TV channel on the Tivo box rather than anything from the TV. You don't say what model TV you have but if it is a newish one it may not have an analogue output which I think your loop amp needs but you can get a digital to analogue converter fairly cheaply on Ebay. Could you give us a bit more detail - TV model, Loop amp model, whether the loop amp is connected to the SCART output on the Tivo box. If you can get the sound output from the TV into your Loop amp it should work with your DVD player. Neil

link to this comment
Neil Bell's 106 posts GB flag
Saturday, 25 February 2017
Carole Redgrift
2:06 PM

Neil Bell: Hi Neil.
My TV is a Samsung. The hearing aid loop is a Sarabec LA215. The loop has been connected up to the Tivo box by a Red and White connectors (sorry I don't know the name of these types) not by a scart.
The Tivo is connected to the TV by a HDMI cable.
My separate DVD machine is connected by a scart to the TV. It has no other means of connecting. I hope this info is enough for you.
Thanks Carole

link to this comment
Carole Redgrift's 2 posts GB flag
Select more comments

Your comment please
Please post a question, answer or commentUK Free TV is here to help people. If you are rude or disrespectful all of your posts will be deleted and you will be banned.

Privacy policy: UK Free Privacy policy.