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Digital TV - David Nelson (7th Jun 2004 - 13:03:45) For the past 10 days or so we have been unable to receive BBC1/2, ITV1/2 and ITN News through our digital box, although before it was fine. All other channels are OK. Anyone else having this problem? David

Re: Digital TV - Alex Cameron (7th Jun 2004 - 13:50:46) Hi David I answered an email recently on the same question. Atmospherics can affect reception with digital tv in exactly the same way as analogue. What is your reception like with the normal analogue channels? Do you have an amplifier? Have you done any software upgrades recently? Have a look at the 'technical information' panel and see if you have the latest downloads. Do you have an old onDigital box? Do you know which transmitter your aerial is pointed to (Hannington, Midhurst etc)? I'm going to at the Beeb later this week so i'll ask around if anyone knows about any upgrade work going on at all. 2 out of the 6 terrestrial muxes (multiplexes - sets of digital channels) transmit differently to everyone else, using QAM64 instead of QAM16. The first set are Five, QVC, Bid-Up and TVTravelShop, and the second set are ITV1, ITV2, ITV News and C4. QAM64 allows you to fit in more information, but suffers from more interference problems. I'd expect problems with those groups, but not with the BBC channels. I'm in the centre of Liphook and have had only intermittent problems so far. This is what DigitalSpy says about upgrading your reception: To find your local DTT transmitters you will need a grid reference from where you live. This can be obtained from http://www.gazetteer.co.uk/index.html or http://www.streetmap.co.uk/streetmap.dll?GridConvert? (enter your postcode, select Postcode underneath, click Convert and use the LR value obtained in the Wolfbane site below). Put the grid reference into both of these links: http://www.wolfbane.com/cgi-bin/tvd.exe? and http://www.wolfbane.com/cgi-bin/tva.exe?. This will then give a list of both ATT and DTT transmitters in your area. Compare the aerial groups of the transmitter you intend to receive DTT from in both of the above links. If the groups are the same you should be able to receive all the Freeview channels, depending whether the strength of each of the muxes is sufficient (many DTT transmitters have muxes transmitting at different powers). If the aerial groups are different you will need to upgrade your aerial to receive all the Freeview channels. Aerial groups are as follows: A: 21-37, red B: 35-53, yellow CD: 48-68, green E: 35-68, brown K: 21-48, grey W: 21-68, black The colour refers to the bung in the end of the aerial facing the transmitter. Some aerials have the group stamped inside the coax connector box. In addition a group W (wideband) aerial can be distinguished from group A, B or C/D aerials by the fact that the elements along the length are unevenly spaced. Once you have the above information, then you can get a good local aerial installer to do the necessary work. If you intend to do the installation yourself: Use a compass to get the direction of the aerial to the transmitter initially, using the bearing from the Wolfbane site. Use CT100 (satellite grade) coaxial cable for the aerial downfeed and preferably have no joins in the cable. CT100 can also be used for the connections between STB/VCR/TV and will offer improvements over equipment supplied leads. If you are still unable to get a satisfactory signal, then a masthead amplifier or a head amp (mounted as near to the aerial as possible) may help. Some people use internal amplifiers/boosters and these may help, provided the original signal is pretty good. Otherwise you will just amplify noise. A larger/higher gain aerial can be beneficial, as these usually have lower acceptance angles for a good signal and can help eliminate impulse interference. If you have a loft installation, angling the aerial slightly upwards may also prove beneficial in eliminating impulse interference. If you need to upgrade your aerial then wideband (group W) would be the recommendation, but this may still be a useful upgrade if you have problems receiving the DTT signal using your existing aerial, even though it is the correct group. This is because in the future channel/mux numbers may be re-allocated and/or additional muxes added after analogue switch off. It should be noted that wideband aerials are not as efficient (gain wise) as grouped aerials and a larger wideband aerial may be needed to compensate for this.

Re: Digital TV - Freddie Dawkins (7th Jun 2004 - 14:38:22) Alex - Another ? for you. BBC1/BBC2 and ITV1 frequently break up and either freeze or get out of pic/sound sync. Yet when we switch back to terrestrial receiver, no problem. Is this common with Sky dishes? thx Freddie

Re: Digital TV - Alex Cameron (7th Jun 2004 - 15:17:04) Yes it is common, as Satellite is affected in the same way by atmospherics. I can't remember which satellites (and/or the corresponding transponders) those channels bounce off. Sounds like you need someone to take a look at your dish alignment. Switching between analogue and digital sat will only show you if there is a generic problem 'playing out' the transmission at the broadcaster's HQ really. Digital TV uses the MPEG-2 format (most channels use less than 10mb/s), which has what's called forward error correction (FEC). Errors in transmission/reception will show up as square blocks and/or green patches. Bear in mind that a STB can get 'confused' due to interference - the way they are designed is to treat anything 'confusing' as an error, hence no 'ghosting' on DTT, and a more sensitive reception. Interestingly, did you know that you don't need to subscribe to Sky to get Satellite TV?

Re: Digital TV - Allan (7th Jun 2004 - 17:39:44) David/Freddie, Had the same problem last year. Got it fixed very easily & cheaply. Give me a ring at the B.F.I. & I will give you info. Cheers, Allan.

Re: Digital TV - Freddie Dawkins (7th Jun 2004 - 18:18:30) Thx, Alex and Allan - Alex - Makes sense - thx. Allan - will give you a call later. rgds to each Freddie

Re: Digital TV - Mike Grimes (7th Jun 2004 - 23:34:06) Makes sense Alex? Patronising or what? Made no more sense than the wiring diagram for a nuclear submarine. That said, Alex, I noted that you said that you do not need a Sky subscription to view free to view satelite broadcasts. This was true but I understood it was being withdrawn (for new applicants) from late last year. If I am wrong I would be very interested in knowing where I could get a viewing card from. Cheers, Mike

Re: Digital TV - Alex Cameron (8th Jun 2004 - 10:23:27) You've never wired a nuclear submarine? And this was the man talking Token rings? :) I could do a "Dummies guide to aerial engineering" or something like that if you want... I think you were referring to the Sky "Free To View" card (FTV)? Its true they pulled them a while ago. Strangely enough you don't actually need a viewing card - the card is used for Sky's conditional access (CA) system (NDS' 'videoguard'), and allows you to view channels that are encrypted. The vast majority of channels do not broadcast encrypted - they are 'free to air', 'FTA' or 'In the clear'. Its important not to get this confused with the fact that Sky own a lot of channels, as well as the platform. That's a political hot potato for another day. Sky is the only real provider of satellite TV in the UK, but they only supply the reception equipment (e.g. dish, box etc) and the lovely menu that collates all the channels and allows you to flick through one by one. They don't own the transmission equipment, satellites or the other channels. In effect, Sky are effectively powerless when they are not allocating what number you will be allocated on the menu. The truth is you can tune into them manually with the same equipment, but Sky provides the most convenient way. If a broadcaster gets a licence from OFCOM, Sky are obliged to put it the on the EPG. The BBC have recently announced the last of Greg Dyke's ideas - "FreeSat", which is exactly all of the above: http://www.satkurier.com/?kat=139&id=12861. You can have a look at some FTA channels at this renowned sat tracking site: http://www.lyngsat.com/freetv/United-Kingdom.html A list of FTA channels by Sky categorisation: http://www.wickonline.com/fta.htm How Satellite TV works: http://web.onetel.net.uk/~uncletony/sattvstuff.htm

Re: Digital TV - Alex Cameron (14th Jun 2004 - 00:17:36) I believe this is known as screwing the competition before they screw you. Goddamn thats one hell of a poker move. 09/06/04 BSkyB announce Free To Air box, launch this year Broadcaster BSkyB is planning to launch a free-to-air satellite package offering 200 TV and radio channels and interactive services. The service, to be launched later this year, will compete with Freeview, the free-to-air digital terrestrial service backed by the BBC and BSkyB. For a one-off payment of £150, it will include the BBC's digital services and Sky News as well as other free stations. But unlike Freeview, a satellite dish will be needed to pick up the service. It was welcomed as the first strategy outline from new chief executive James Murdoch on how to increase customers. BSkyB hopes that the absence of a subscription fee will lure new customers who may eventually switch to a pay-TV package when analogue TV is eventually phased out. News Feed: Raj Baddhan Source: BBC News News Break: 19:28 http://skydigital.mediabullet.co.uk/ http://news.bbc.co.uk/1/hi/uk/3792567.stm http://news.bbc.co.uk/1/hi/business/3795687.stm http://news.bbc.co.uk/1/hi/entertainment/tv_and_radio/3793471.stm

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