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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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Wednesday, 22 February 2012

8:55 PM

Stuart: I realise that the manual might make it appear that way, but the scart lead is only permanently required if the TV being used with the box is of the slightly older variety that does not have HDMI sockets, as otherwise if it does (such as your own) you will most likely find that once the box is set up you can remove the scart lead.

The other thing the scart connection can be used for is to enable anyone with a DVD recorder to transfer recordings over from the V+ boxes own internal hard drive into the external DVD recorder, although if the external DVD recorder is also of the HD (hard drive) type and with a larger capacity than that of the V+ boxes, this procedure can be used to effectively dump what stored in the V+ boxes internal hard drive into the external DVD recorders hard drive, something that handy to be able to do if the V+ boxes drive is getting near to its maximum storage capacity, as once some of the content from the V+ box is transferred into the external DVD device whatever was transferred can then be deleted from the V+ box thereby freeing its hard drive up to enable more programmes to be stored.

On the subject of scart switcher boxes, you always have to ensure that you purchase a selectable type, that meaning it has either one or two buttons (even more on some) on the box to be able each one of its sockets to be selected one at a time, as some types do not have this and purely relies on one device being switched off whilst viewing another, as if this is not done two or more programmes can be seen at the same time, this why the selector button type is essential.

By the way, anything transferred from the V+ box via scart is always in normal SD, as HD (hi-def) cannot be transferred via a scart connection.

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jb38's 7,179 posts GB flag

9:04 PM

Eddy: What type of connection do you have between the TV and the box? and what model of TV are you referring to? The reason I ask is that it shouldn't be necessary to disconnect anything provided that you do not completely switch off (from mains) the box when you are not using it, as if the aerial is linked through the box that will kill the signal.

Anyway if you could give an update on the info requested further advice can then be given.

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jb38's 7,179 posts GB flag
Saturday, 25 February 2012
Gordon Stocks
7:38 AM

tessa: Please can you tell me how to connect tv-freesat-vcr using HDMI cable and do I need to use a scart socket also,There are two scart sockets on the freesat two on the tv and one on the vcr.there is one HDMI cable on each.Thanks

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Gordon Stocks's 1 post GB flag

10:00 AM

Gordon Stocks: Can you please confirm that the VCR only has one scart socket? however if it has then connect the Freesat (HD type?) into the TV using an HDMI cable, then couple the VCR into the Freesat's AV2 scart socket, and finally another scart lead between the Freesat's AV1 and the TV's AVI input.

This arrangement will enable you to record from the Freesat whilst viewing a non Freesat channel (Freeview) on the TV, if you want to play back what's been recorded then as soon as you press play it should feed through the Freesat box and into the TV via its scart socket, but though you will likely have to select AV1 input on your TV's remote control as the parallel connected HDMI input will possibly clash with it.

The reason I asked about the VCR only having one scart socket is that the more normal way of coupling it would be for the VCR's AV1 to go into the TV's AV1, and with the VCR's AV2 connected to the Freesats similar.

If you experience any problems please indicate the model of TV involved and also that of the Freesat box.

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jb38's 7,179 posts GB flag

10:20 AM

Gordon Stocks: Just as an afterthought, in case your TV is of the type that doesnt respond favourably to having two auto-switch inputs originating from the same source i.e: Freesat box, couple the scart lead from the Freesat boxes AV1 into the TV's AV2 socket, selecting that input via the TV's input selector when you want to view anything from the VCR.

When the VCR is switched off after viewing from it the TV should switch back to the Freesat box but it will likely be via the scart socket, so change the TV back to its HDMI input via the TV's input selector menu, you might of course not notice that much of a difference if you dont, but HD will not work unless its via HDMI.

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jb38's 7,179 posts GB flag
1:57 PM
Bishop's Stortford

Why does the quality show 0% and the level show 66% and still not picture on a Ross HD satelitte receiver

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Steph's 1 post GB flag
Steph's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
1:59 PM
Bishop's Stortford

Why is quality 0% despite the level being 66%+ on a dig sat rec

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

3:19 PM

Steph has this dish ever worked? Did you put it up or was it put up correct by a profesional with a proper meter. If it was put up by yourself with a cheap meter with 5 lights you have it on the wrong satellite. One other thing the dishes that come with these type of free to air sat receivers are very poor so that might need changing hope this helps.

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Mazbar's 384 posts GB flag

3:46 PM

Stephanie: Plus in addition to that said by Mazbar regarding the wrong satellite, are you sure that you selected "Astra 2A/B/D & Eurobird 1" from the choice box? as the pre-programmed English channels are already stored in the box so there is no need to carry out a scan, this only being said just in case you are tempted to carry out one.

Is the box you have an HDR6110USB?

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jb38's 7,179 posts GB flag
Friday, 9 March 2012
Mark Petersen
2:40 PM

Mark Petersen: The flash drive connected to my technisat HDFV set has just died. I'm not sure if the Technisat caused this or if the drive itself was faulty. Has anyone out there expereinced the same? I could try a new flashdrive but that's an expensive way to find out. Any help appreciated.

Mark Petersen

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Mark Petersen's 4 posts GB flag
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