SatCure satellite scart peritel lead connection FAQ

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Unfortunately, I can't answer questions about connecting up specific equipment because various manufacturers set their own standards and I simply don't know them all. You should read the following information. If you still can't figure it out, try the links below. Otherwise, you may need to call in a specialist. Or you may be able to enlist help in one of the discussion forums where people with expertise in this field (or the same equipment as yours) will know the answer.

You can get connection help here:

http://www.solihull-online.com/scart.htm

and here:
http://www.dtg.org.uk/consumer/connection_wizard.html

and here:
http://www.radioandtelly.co.uk/connecthelp.php

A Scart system works by detecting 12 volts on pin 8. In other words, if, say, the VCR is ON then it puts 12 volts on pin 8 to tell the TV "here I am - look at me". Likewise the Sky Digibox does the same. if it's ON it invites the TV or VCR to look at it by putting 12 volts on pin 8 (or 6 volts if wide screen transmission).

Obviously, if you have more than one piece of equipment running at any one time, they will be fighting for attention. The answer is to switch one off or to disconnect pin 8 and select it manually ("AV in") when required.

Alternatively, use one of our Scart Switching boxes to select manually the input that you require.

Interference may be caused by video breakthrough.

Cheap and cheerful Scart lead on page 4.

High quality lead with gold-plated pins.

Click HERE for more info.

"Scarting out Right"

To some installers, a Scart lead is a means of earning an extra tenner on each installation; to others it's a nightmare. Scart leads come in various lengths and types but the main two subdivisions are "fully wired" and "part wired."

The scart system was developed some years ago before satellite receivers and decoders were considered. For this reason, just one connection (pin 8) is used for signalling purposes. The intention was that a video recorder (for example) would put a "here I am" voltage on pin 8 when it was switched to "play." The TV would respond by showing the video signal (from the Scart lead) instead of the terrestrial picture from the aerial input. The main advantages of the Scart connection are that the picture is "cleaner", because it doesn't go through a modulator then a demodulator, and stereo audio is also possible, together with surround sound when available

Dolby Prologic (when transmitted) is encoded onto the normal Right/Left audio channels on pins 1 and 3 respectively. All you need to do is to connect these to a D.P. decoder. If there isn't one built into the TV set then you'll need a separate one, usually incorporated into an audio amplification system..

The Scart system gives a problem if, for example, the Scart lead is used to connect a DVD player to the TV. Now whenever the DVD player is on, it puts a voltage on pin 8, which makes the TV switch the DVD picture in, even if you don't want it to! Even worse - if the DVD player is ON but not playing, you may see just a blank screen - very confusing! The only answer is to disconnect the wire from Scart pin 8 and use the TV "AV" button to select the DVD picture only when it's wanted. If you have in addition a Satellite Receiver and a Terrestrial Digital receiver then you have major problems

Video breakthrough

Another problem which arises is that there can be signals or interference emanating from the TV on the Scart wires. This can cause "ghosting", "shadows" or lines on the picture. Pin 19 (at the TV end) is a likely candidate and should be cut, otherwise picture interference or "ghost pictures" may occur - often of the terrestrial programme behind the satellite programme. If you can't get inside the plug to cut the wire, simply twist the pin off (at the TV end). On most plugs you can use a sharp point to press the tiny tag on the flat pin which will let you push it inside the Scart plug. That way, if you get it wrong, you can tease out the tiny tag to lock it and push it back again. You can safely disconnect pin 19 (at the TV end) for any equipment that is sending its video TO the TV set and not expecting to receive a video signal back. For example: a Sky Digibox or a Freeview receiver.

Picture distortion may occur if the satellite receiver or decoder is incompatible with the TV or VCR. Occasionally the video level from the Scart connection is too high for the TV or VCR to accept. The answer is to modify a Scart lead in advance and to keep it in the van. The last thing you want is to have to solder in the customer's living room! You will need two 1/4 watt resistor of value 27 Ohms and 47 Ohms. Disconnect the wire from Scart pin 20 (video in) and solder the 47 Ohm resistor from pin 20 to pin 17 (video ground). Solder the 27 Ohm resistor from pin 20 to the end of the wire which you cut. The resistors will reduce the video signal. Mark the modified end "TV". You can now use this modified Scart lead for testing purposes and, if it cures a problem, leave it connected and make another to put in the van later.

The same problem can occur with audio levels. I don't know the output impedance of a Sky Digibox but, assuming it's around 1k, this simple resistive divider network should work. It divides the signal in the ratio 180/1000 (about one fifth). The resistor values can be adjusted to suit your particular application. 1/8 Watt resistors can be used and will easily fit inside a Scart plug. You'll need two pairs of resistors. R1 is connected to Scart pin 1 (Right) and pin 3 (Left), with the wires that were connected to those pins going to the respective junctions of R1 and R2. "Common" goes to pin 4.

Cheap and cheerful Scart lead on page 4.

High quality lead with gold-plated pins.

Click HERE for more info.

Audio breakthrough

faint audio getting through (usually from the TV programme) can usually be cured by cutting the wires from pins 1 and 3 in the Scart plug at the TV end (see diagram below). If you don't want to cut the wires you can twist the flat pins off. On most plugs you can use a sharp point to press the tiny tag on the flat pin which will let you push it inside the Scart plug. That way, if you get it wrong, you can tease out the tiny tag to lock it and push it back again.

A Digital Receiver is usually capable of providing Red/Green/Blue signals which can be fed to a suitable TV to give (in theory) better picture quality. However, a side effect is that onscreen menu graphics might roll and Teletext might be affected, too. The picture might shift to the left (due to delay line mismatch) or the contrast might be too high. The answer is to "TRY BEFORE YOU BUY" to ensure that your Digibox and TV are compatible. If not, buy a different TV.

You can pay more for a gold-plated Scart lead but what is the advantage? Well, unless the plug pins *and* the socket pins are gold plated, there is unlikely to be any advantage at all.

SCART = PERITEL connections:  

  • 1 Audio out RH
  • 3 Audio out LH
  • 5 Blue earth
  • 7 Blue
  • 9 Green earth
  • 11 Green
  • 13 Red earth
  • 15 Red
  • 17 Video out earth
  • 19 Video out
  • 21 Earth (shield)
  • 2 Audio in RH
  • 4 Audio earth
  • 6 Audio in LH
  • 8 Status
    • 0v = internal bypass
    • 12v = select external
  • 10 Clock / Data 2 4) Control bus (AV.link) or undesignated
  • 12 undesignated (status)
  • 14 undesignated (status)
  • 16 RGB status
  • 18 Video in earth or undesignated
  • 20 Video in

This is how the pins are numbered when you look at a Scart socket. This is also correct if you are looking into the rear of a Scart plug at the solder ends of the pins.

Phantom PVR

The Phantom PVR brings together your VCR and standard Sky Digibox. Using the Sky Guide, select a programme that you want to record. When it's about to start, the Sky box sends a signal to the Scart socket that your Phantom PVR is plugged into. The device then sends an infrared signal telling your VCR to turn on, select the channel and start recording, just as if you were there and pushing the buttons! You still have to put a tape in but it's a lot cheaper than SKY+. (Be sure to select "Scart control ON" in the Digibox "Picture settings" menu - press "Services" then 41).

>"How do I connect my Sanyo TV, ONdigital box, Sky Digibox,
>Amstrad VCR, MSS100 and Yamaha Dolby Prologic amplifier
>together?"

With a great amount of difficulty!.

Assuming you have a Digibox, a VCR with two SCARTs and a TV with two SCARTs, it's pretty simple. Connect the Digibox via two SCART leads to the TV and VCR, then connect the VCR to the TV via a third SCART lead.

This gives you full SCART and stereo audio connections between all items, and everything works correctly. It's also wise to disconnect the SCART switching on the lead from Digibox to TV. Simply select the SCART manually when watching the Digibox.

I would also advise cutting the RGB leads in the Digibox SCART as well because some TVs lose their teletext capability when the Digibox RGB is connected. The new Panasonic boxes seem far worse for this!.

To connect a Dolby Pro-Logic amp, use phono connections from the Digibox to an Aux. input on the amplifier.

As for adding an OnDigital box and an analogue satellite receiver, it can't be done in any satisfactory manner. There are various ways around this, but none are very good, and all require fairly complicated operations by the user.

Some TVs have more than two SCARTs. These help somewhat, but you still have the problems of recording in stereo.

>"Can I get surround sound if I Scart a Digibox to
>my TV which has built-in Dolby Prologic?"

If it's connected via SCART you will get Pro-Logic automatically - provided that the programme includes it. Movies that have D.P. encoded sound are transmitted with all the necessary information within the L + R channels on the analogue signal. So *any* satellite receiver with stereo outputs will pass the information to a D.P. surround sound decoder/amplifier.

For Sky Digital, the Pro-Logic information (when available) is included in the standard stereo sound track, and requires no more bandwidth. Many of the programmes on Sky Digital (and Sky analogue) are in Pro-Logic. "Dolby Digital" is being introduced by BskyB for selected programmes at the end of 2001. To make use of this, you'll need a Sky-Plus Digibox or another model which has an optical digital audio output (and software enabled).

>What's the difference between the Dolby Prologic used in analogue and digital
>satellite transmissions and the Dolby Digital Prologic (is that correct?) used on
>DVD discs?

It's more usually "AC3", also labelled as "5.1" (left front, right front, centre, left rear, right rear + sub-woofer). Pro-Logic only has mono rears and no separate sub-woofer channel.

(These replies by Nigel Goodwin)

Read MORE about Scarts and Scart switching boxes HERE <----

DISCLAIMER
This information is given in good faith, based on several years of workshop experience involving thousands of repairs. No responsibility will be accepted for any death, damage or injury caused either directly or indirectly by the use of this information. The reader should check the facts himself. It is assumed and stressed that the reader will be familiar with good, safe, electronic workshop practice and will be familiar with all tools, components and terms used. If there is any doubt about the reader's ability to carry out such work competently and safely, the work should be referred to a specialist engineer.

THIS FAQ IS NOT APPROVED BY SKY OR BY PACE
End of FAQ

Unfortunately, I can't answer questions about connecting up specific equipment.

A Scart system works by detecting 12 volts on pin 8. In other words, if, say, the VCR is ON then it puts 12 volts on pin 8 to tell the TV "here I am - look at me". Likewise the Sky Digibox does the same. if it's ON it invites the TV or VCR to look at it by putting 12 volts on pin 8 (or 6 volts if wide screen transmission).

Obviously, if you have more than one piece of equipment running at any one time, they will be fighting for attention. The answer is to switch one off or to disconnect pin 8 and select it manually ("AV in") when required.

Alternatively, use one of my Scart Switching boxes to select manually the input that you require.

http://www.satcure.com/accs/page4.htm

For more information about wiring and minimising interference, please see this booklet "Piping TV Around the House".

SKY +

A customer raised a question about no audio output from the VCR scart on the new Pace Sky plus receiver. Here is some info supplied by Pace:-

"I have had a word with our engineers and it seems this is a particular feature of certain STBs when looped through certain VCR's (Sony in particular) and some (very few TVs) that hold Pin 8 High at all times.

The recommended fix is to simply put the STB in to standby mode to allow Pin 8 to be dropped and allow audio to loop through.

FYI - Sony VCR's are renowned for leaving pin 8 high when stop is triggered on the VCR. Sony have even implemented a button on the RCU on some models to drop pin 8 ("DISP"), as they are aware of this "feature."

I have also read that using a Scart to Phono lead might solve the problem of Pin 8 switching, however this may mean that Wide screen switching can be affected."

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using Scarts, connecting Scarts  

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Copyright ©1997-2011 Martin Pickering
Version 1.4 updated on July9, 2011
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