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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

Sunday, 24 August 2014
Neil Bell

5:38 PM

Ann You need an aerial to plug in to your TV. if you don't already have one you might get away with a set top aerial as you live fairly close to Crystal Palace. Otherwise check with your neighbours as to what they use. Next up would be a loft aerial and then a rooftop aerial. Neil

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Neil Bell's 106 posts GB flag

8:56 PM

ann :

Having worked in that area I would expect the reception from Crystal Palace in your part of Waddon should be reasonable but you may find that the traffic on Stafford Road may make reception using a 'set top' aerial somewhat variable.

I would suggest having an aerial installed, preferably of the log-periodic type - a good aerial installer will know what that means - as that will be suitable for the foreseeable future services.

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MikeP's 3,056 posts GB flag
Friday, 29 August 2014
9:45 PM

bought a freesat box connected it to tv by hdmi cable also connected video player to tv by scart, should it be video to sat box

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les's 1 post GB flag

10:54 PM

les : No, the freesat box should go to the TV. The Video player should also go to the TV, via scart. If you want to record from the freesat box to video (although if its a Freesat PVR thats obviously pointless), then you should enable the Freesat box to output to scart, and feed into into the VCR. The manual should tell you how to do it, if its possible and you really want to do it. Personally, I wouldn't bother, and I'm not sure what you'd want to use the VCR for these days either, but there you go.

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MikeB's 2,579 posts GB flag
Wednesday, 15 October 2014
M Bevan
12:03 PM

Recently cancelled Sky TV, but can still use for freeview stations but not for Motors TV, which I enjoyed watching.
In another room I have recently installed a Talktalk TV box which recently I found out I should receive Motors Tv on ch. 71. Confirmed by Digital Advice who also advice as I do not receive BBC News HD on here that I am not receiving Com7 so appears to be an aerial issue. Only receive BBC 1,2, 3, ITV C4 & CBBC HD channels. Like most people I am out of my depth as have little knowledge and wondered what I should do to receive com7? Change positioning of aerial or fit new Aerial, SLx 27985K4 4G 64 Element Aerial for Digital TV Kit as viewed on amazon?
Would like to add I have had difficulties on tuning both digital TV's to receive BBc & ITV channels but did so manually in the end.

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M Bevan's 3 posts GB flag
M's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
Mike Davison

5:52 PM

M Bevan: If you are getting MotorsTV on Freeview at location 71 then you ARE receiving COM7 so there's no reason why BBC News HD(locn.107), BBC4 HD(locn.106) and others should not be there. You must be using Pontop Pike and if they are not there, do a manual tune on channel 31 and ensure DVB-T2 standard is selected for the scan.

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Mike Davison's 127 posts GB flag
Mike's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage

9:29 PM

M Bevan
Does your TV have the DVB-T2 facility? Do you get BBC1 HD? If not then your equipment probably can't receive the HD multuiplex, COM7 and hence can't get MotorsTV.
If your equipment is FULL HD (and not just HD Ready) then you may need to check that it is set to use the DVB-T2 transmissions.

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MikeP's 3,056 posts GB flag
MikeP's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage

11:02 PM

M Bevan: If your getting CBBC HD, we have to assume you've got a T2 tuner, but your just 17km from Pontop Pike, which is broadcasting on Com 7. On the other hand, do you have a smart TV?

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MikeB's 2,579 posts GB flag
Thursday, 16 October 2014

12:33 AM

M Bevan: A quick scout around the rooftops in your area did not reveal any particular level of aerial sophistication being used for reception from Pontop Pike, and with a terrain check on the signal path between PP and your location indicating a clear line-of-sight, albeit that the signal is seen to skirt over a couple of sizeable obstructions at a relatively low angle.

This coupled to the fact of Pontop Pike being located at just over 10 miles away would not justify an aerial of the type suggested (by yourself) being necessary, and indeed an aerial known as a Log36 would be perfectly adequate for applications such as yours. (As illustrated on the link below)

The other point I wondered about being, when you said that you had difficulty tuning BBC & ITV channels, are you purely referring to having possibly picked these channels from either Bilsdale (BBC / C26 - ITV / C29) or Fenham (BBC / 27) - (ITV / C24) ?

As MikeB has said, if you are receiving CBBC HD (PSB3) then your TV must be fitted with an HD (DVB-T2) tuner, but though, maybe you could indicate the model number of the TV in question.?

ATV`s Choice Of Aerials for digital TV

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jb38's 7,179 posts GB flag
Mike Davison

8:53 AM

M Bevan: Sorry. Channel I suggested is wrong. COM7 from Pontop Pike is 33 not 31.

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Mike Davison's 127 posts GB flag
Mike's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
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