Kitz Forum
Chat => Tech Chat => Topic started by: broadstairs on January 25, 2009, 05:27:14 PM
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I have just come across a problem which is likely to hit people with older IDTVs and set top boxes. There has been a change in the standards used to broadcast the DVB signals in the UK which has moved the goal posts and many older set top boxes and IDTVs may stop picking up channels correctly or even at all when you re-tune. We have two Oggle set top boxes bought from ASDA about a year ago and it is these which now place BBC1 etc on channels in the 800 range rather than picking up the correct channel numbers.
Apparently the problem can exists with any equipment puchased without the Digital Tick logo which is relatively recent and it seems that there is no real solution for this problem. I have Googled this and it has been known about for many months now but only comes to light if you re-tune your IDTV or set top box.
So be warned and check your equipment before re-tuning to make sure you are not affected. If your set is within warranty then you should be OK and be able to get it fixed, but many which are affected will not be as they will be more than 12 months old.
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Funnily enough I re-tuned my yesterday as there are some new channels Quest, not up and running yet but coming soon and YouGov are the ones that spring to mind, it was okay though, but I only bought my last summer, all the same it must be damn annoying if your boxes are just out of warranty.
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Ours is a Goodmans one which is 4 year old and seems fine (at present)
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As a retired broadcast transmitter engineer I thought at last I may be able to help others on the Forum which has been so much help to me. Unfortunately the situation is not straightforward and I am contacting old colleagues and acquaintances to get the latest info. What I would endorse in BROADSTAIR's post is the caution about not rescanning unless it's really necessary. It's not clear to me if that could completely kill a digibox or iDTV but it might I suppose. If it merely found BBC1 on 807 say it might be possible tp relabel it as 1 in your "Favourites" which most boxes have. The final resort is to buy a digibox from Tesco or wherever for £20 or and plug that in. Even Integrated DTV's have SCART sockets which will accept the digibox output so all is not lost. When my more expert friends have responded to me I will post again with a more definitive answer.
Tony
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Is this another "NEW" problem or just the one from last years being discussed?
As for the set top box's that are even still in guarantee, apparently the suppliers were saying it's not their problem and therefore could/would not do anything about it, as there is nothing wrong with the box as such, the problem is with the signal transmitters, (so tough).
If this is last years problem then there is a list of box's that are affected available on the web.
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Is this another "NEW" problem or just the one from last years being discussed?
As for the set top box's that are even still in guarantee, apparently the suppliers were saying it's not their problem and therefore could/would not do anything about it, as there is nothing wrong with the box as such, the problem is with the signal transmitters, (so tough).
If this is last years problem then there is a list of box's that are affected available on the web.
Well its certainly been known about for a year or more but it has all depended on folk finding out as transmitters are upgraded/changed as has happened to our transmitter relatively recently.
Its all very well for the manufacturers to say 'tough' but I bet there are probably many people with now useless set top boxes or TVs and I think it is very wrong for this to have been apparently covered up in this way. We have all been told for ages now 'when you but a new TV buy a digitally capable one' so someone in my view in the Government should be held responsible for this, although I am realistic that there is more chance of a pig sprouting wings and flying than anyone doing anything about this. So far I've not come across a definitive list of affected boxes or TVs, the information I've found is very fragmented and needless to say nothing at all on the DigitalUK website, what was there has been removed!
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I have been doing some more reading on this problem and it appears that it may be associated with a recent change to something called the NIT (approriate acronym I think :lol: ) the Network Information Table and is associated with the EPG (Electronic Program Guide) I believe. This change I thinkl was implemented country wide sometime in the latter half of 2008.
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An interesting thread.Im hoping my sony pvr doesnt apply to this.Its not too bad if its boxes like my 6 year old ex-itv digital one, as a £16 onn box from asda performs better.
You would think a software update would sort it out,but there again look at windows
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I don't know if this is of any help, but here it is:
You can download the pdf which shows the "so-called" complete list.
I know for a fact that this is not a complete list as Daewoo is not listed, yet on the list I saw originally some Daewoo models were also reported as being effected.
http://www.freeview.co.uk/freeview/Resolutions/Will-my-digital-equipment-continue-to-work-at-switchover
These makes & Models are not upgradeable.
ONdigital
Alba / Bush ONdigital sets STB ported inside IDTVs 1998 *
Nokia Mediamaster 9850T Set Top Box 1998-2002 *
Pace DTR730 Set Top Box *
DTR735 Set Top Box *
Philips DTX 6370 Set Top Box Nov98-Aug01 *
DTX 6371 Set Top Box " *
DTX 6372 Set Top Box " *
Pioneer DBRT200 Set Top Box *
DBRT210 Set Top Box *
Sony VTX-D500 Set Top Box *
Toshiba DTB2000 Set Top Box *
Freeview
Pace DTVA-T (Wedge Adaptor) Set Top Box 2001 *
Samsung SIRU200i (Without M suffix) Set Top Box 2003 *
Note: There may be other products that are affected. If your box or IDTV has stopped working and is
not listed contact your retailer or the manufacturer for confirmation that it is a 2K COFDM only model.
2K only IDTVs can be upgraded with a modern digital set top box or digital recorder. Look for the
‘digital tick’ when buying any new TV equipment. Any 2K only sets being used to just monitor
pictures/sound from games machines or DVD players will continue to work as before.
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I always switch ours off at the mains at night.(as we are told to do by the energy saving lobby).When I turn it on in the mornings I get an screen message to leave it on stand by 24/7 or it won't update the EPG.I just press the menu button to by pass this and then select whatever I want to watch.I periodically do a scan to update the channels without any problems.
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There are two problems with Digital TV which can happen. There is a parameter which is called transmission mode and this is set to either 2k or 8k and the list OF has shown is the list of boxes which cannot be upgraded to cope with this change. AFAIK the only area where this has been a problem is the Borders and the list specifically applies to this area only. From what I have read the 2k 8k thing has not been approved for general use yet, OFCOM are supposed to be making a decision on this for the rest of the country later this year.
The problem of the changing NIT is likely to be much more widespread and as I have found with my Oglle box from ASDA it does not cope with an extended NIT and places a whole bunch of channels in the wrong sequence. This problem is likely to be much more widespread. Some boxes you can re-order the display sequence so that they appear in the correct order, others you cannot. Some boxes and possible TVs simply wont work correctly, although right now I have no definite information on which if any boxes will fail to find the channels.
This is just another case of the powers that be not thinking things through and running rough shod of the people like us at the sharp end. It will be especially confusing for folks who are not technically minded, and possible a case for exploitation by unscrupulous TV repair men/shops.
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My boxes/TV's are getting very confused now.
As the number of channels increases on each transmitter we're getting overlaps; I can now pick up well over 100 channels in total from 2 different main transmitters (Crystal Palace and Hannington).
And each box has its own way of deciding how to number them.
There seems to be no facility to "preselect" your primary transmitter. :(
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The 2K/8K change which might happen is another problem really which ma/will raise its head in the future. The main hiccup at present is the implimentation of the use of NIT to allow different programmes to be broadcast in different areas of the country. I don't blaim the "powers that be" as Broadstairs does since the full digital Spec has always allowed for the use of area NITs. The problem rests with the receiver manufacturers who didn't fully comply with the spec. It is interesting that the original OnDigital boxes some of which are still in service all cope with the recent NIT changes because they adhered to the full spec.
Tony
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I think my old nokia itv digi box displays bb1 at channel 801
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I had gathered from friends with old OnDigi boxes and from my own experience that they all complied fully with the spec. but from robinsteele's post it seems I was wrong. I have heard that misreporting of channel numbers can arise if the signal strength in your area changes drastically but that's me clutching at straws!
Tony
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Hi Tony,dont take my word for it,as I gave the nokia box to my uncle and ive not powered it up for 3 odd years.It would definately freeze all the time though and would need a forced reset.Ive not had a problem with that onn £16 chatty from asda.Ive even got it hooked up through my fancy sony pvr :)
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Hmmm... this may well be why my media centre channels are now all Muxed up on the TV card :mad:
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I just wish I could even get the freeview channels. :(
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How can you not get freeview
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Plenty of areas where the signal is not strong enough for Freeview until after the analogue switch off when the digital signal will be boosted. I believe one common indication is that if you can't get Channel 5 on analogue then the signal in your area won't be strong enough for Freeview. In that case the only option (apart from waiting until switchover) is to try using Freeview on Freesat.
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I believe one common indication is that if you can't get Channel 5 on analogue then the signal in your area won't be strong enough for Freeview.
No, I'm afraid there's no connection between the two things. Channel 5 was squeezed in by relaxing the rules about co-channel interference and so on, and there are several areas of the country where it simply wasn't possible to find a frequency for the 5th channel which wouldn't result in interference with other channels in the area. And there's no channel 5 in this part of the country (Kent) because of concerns about interference with French channels.
Freeview has different considerations. In order to avoid interference with analogue channels, the Freeview channels are transmitted at very low power (e.g. 2% of the analogue power). People living in weak signal areas may not be able to get good Freeview reception, simply because the the signal isn't strong enough. Digital TV is more robust than analogue, but it's not perfect of course. When analogue is switched off, the Freeview transmissions can have an increase in power which should make them receivable by everyone.
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The problem for us in Broadstairs is the proximity to the French and at the same time we switch off analogue they do as well and both up the power. If you check the official sites we dont get Freeview but because of where we are (quite high on a S facing slope we get our signal from Dover and we do get Freeview with a good signal strength at present anyway. Other places locally are not as lucky.
Strange thing about this problem is that when trying to re-order my box to get the BBC and ITV channels in the correct places I find that it seems to have found more than one copy of each, although this cannot be since we only get a signal from one UK transmitter, and the other IDTVs only find a single copy of each station. Also funnily enough I've found that this Freeview box does allow for the 2K or 8K transmission mode as well as different guard intervals but it cannot cope with the NIT changing!
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>> I find that it seems to have found more than one copy of each
I've got a digital TV card in this PC, and it picks up several duplicates too. I think in my case, although I specify Dover as the source, I also pick up Bluebell Hill, and that's where the duplicates come from.
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Plenty of areas where the signal is not strong enough for Freeview until after the analogue switch off when the digital signal will be boosted. I believe one common indication is that if you can't get Channel 5 on analogue then the signal in your area won't be strong enough for Freeview. In that case the only option (apart from waiting until switchover) is to try using Freeview on Freesat.
Ive not looked into freesat,but i believe you need a dish and box.I dont know how much that costs,but i would think sky lowest package would be much better,then when the years up,keep the stuff and use it as a freeview box.I think itv digital/freeview was aimed at people that werent allowed planning permission for a sky dish.
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How can you not get freeview
Don't ask - long story.
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A further complication in the South if you receive your Digital TV from the Rowridge transmitter on the Isle of Wight, it was announced today (28th) that the channel frequencies will be changed in March and that the analogue Ch5 transmitter will cease transmission. This will require a rescan to find the new frequencies and get Ch5 back and may precipitate problems for old digiboxes as Broadstairs indicated when starting this thread. I have an old pvr with a hard drive recorder that looks set to expire unless I update the firmware or there is an over air download nearer the time. I'm still gathering information for a comprehensive summary of the situation as I promised earlier but this news has instilled more urgency into my search 'cos it will now affect me in 2 months not in 2012!
Tony
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The promised overdue summary! Sorry it's so long.
Recently one or two TV regions have had their analogue services shut down and the changeover to digital terrestrial TV (Freeview) has been made. In these areas some problems have cropped up due it seems to some set top box manufacturers not adhering strictly to the specification which they were given when DTT first started. Some of the manufacturers have said that the spec. was not specific enough but this argument will probably never be entirely resolved. From the viewers point of view in some cases their digital TV reception fails irreparably, in others it fails to receive some programmes but can be rescanned and in others a rescan removes all programmes. In the vast majority of cases TV reception continues apparently unaffected.
The main change to transmission that will affect all areas is the introduction of the Split Network Identification Table, the so-called Split NIT and this was introduced nationally last summer around July/August. It effectively enables the transmission of more channels although many have to be shared and allows more local programming than was possible originally. The NIT is used by the set top box to identify the channel and give it a name, BBC1 for instance, and also makes sure that the Electronic Program Guide or EPG displays the right information alongside its channel name. This becomes especially important if you have a digital video recorder (or PVR as they are often called) because the EPG allows you to select the programmes to be recorded at the click of the remote. And of course it would be most inconvenient if the EPG showed another channel’s programmes or times.
The effect of introducing the Split NIT varies depending on how the set top box interprets it and this in turn depends on the software/firmware being used to decode it. Some old boxes give up the ghost entirely and may not be revivable although many of the old OnDigital boxes are reported to handle it properly. Other set top boxes will report “New Channels Found” or something similar and suggest a rescan. Still others will rescan automatically and also report “New Channels” but require no action from the viewer but might have lost some channels.
The problem with rescanning is that until it is tried you don’t know if yours is one of the boxes affected adversely by the change to a Split NIT and nor how bad the problem is, and this is what Broadstairs was warning about in his initial posting. You would think that it would be a simple matter to publish a list of all affected models but, because of legal liability wrangles, that doesn’t seem to be likely to happen. (See the link to the Freeview UK site for some model numbers.) Some of the manufacturers that have had reported problems are Novapal, Daewoo, Labgear and Triax but only on some early manufactured models, but the affected models are rendered unusable by a rescan. Other manufacturers whose products may be affected include Access Devices, Sagem, Thomson and Panasonic but I’m lead to believe that over air downloads of upgraded software (OADs) will resolve their problems. This may not be possible after a rescan because the channel the update is being broadcast on may not be receivable after the rescan. Of course your initial action for any failed equipment is to return it to the seller under the Sale of Goods Act but most will require a receipt as proof of purchase and after a few years who can find receipts, but for recently bought equipment this is the way to go.
OADs are broadcast according to a schedule you can find at http://www.dtg.org.uk/retailer/download_schedule.pl but it only covers two weeks at a time and DTG (Digital Television Group) are dependent on the respective manufacturers as to the timing of each OAD availability. This means you have to keep checking. This is not really necessary in many cases because many set top boxes automatically search for OADs that are relevant and download and apply them. I have to resort to advising you to consult your particular user’s guide/handbook for details on updating. If you discover that DTG has scheduled an OAD for your model you can force a manual update. Once again the handbook will tell you how.
My own digital recorder is a Digihome PVR80 which I bought on Ebay but which was sold initially by Argos I believe. This make together with many others were made by the Turkish company, Vestel, and rebadged. Vestel manufactured (and still does manufacture) set top boxes and PVRs for many well know names and good quality kit they are too, but they do need the latest software loaded to handle the split NITs so I’m watching the DTG schedule carefully hoping for an OAD before 25th. March when I have to do a retune because Rowridge (my local transmitter) channels are being altered. The more modern PVRs sold by Argos are equipped with the latest software and should be fine but do read your handbook about OADs. It’s always better to have the latest software and it should all happen seamlessly if you follow the handbook instructions. This may mean leaving your recorder switched to standby overnight (not “OFF”) which allows it to power up when your not using it and do its thing if it finds an OAD. Many engineers and environmentalists will find that unacceptable but it may be easier than a forced update.
I do have a fallback position in that my recorder has a serial input socket and I have downloaded the latest software .bin file and in extremis I can update it locally but that’s more trouble than an OAD so I’m keeping my fingers crossed. I expect other PVRs have the same facility but the procedure may be different to the Digihome. PC cards for digital reception may be able to download software updates from the card manufacturer’s site.
Another change that will happen at Digital Switch Over in your area is the change to so called 8K from 2K modulation. Don’t ask what this means please! Just be grateful it is likely that all the boxes surviving up to DSO will almost certainly work with 8K if they have up to date software.
Some other links you may find helpful or interesting.
http://www.futaura.co.uk/vestel.html
http://www.digitalspy.co.uk/forums/showthread.php?p=29039388 Serial port update procedure
http://www.freeview.co.uk/
http://www.freeview.co.uk/freeview/Resolutions/About-Freeview-availability/Aerial-information/Transmission-changes-affecting-some-Freeview-digital-boxes
http://www.digitaluk.co.uk/when_do_i_switch/meridian/rowridge
As a last resort even if your prized integrated digital TV bought at some very high price at the outset of DTT turns out to be unupdateable (Is that a word?), you could purchase a set top box at a supermarket for £20 or less and connect it to your TV with a scart cable. If the TV is so old it doesn’t have a scart you can buy a box with a built in modulator that you can connect to your TV via the aerial as we did for video tape recorders. In our kitchen we have an old TV receiving DTT by this means although it will have to go when small integrated digital TVs become cheap enough. My wife isn’t keen though because you can’t store useful stuff on top of an LCD screen like you can a “proper” TV!
Tony
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Thanks Tony for a very good overview and summary of the problems.....
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I have noticed that the video plus on my pvr is not accurate.I thought that it beamed info to start and stop the recording but ive had a couple of films recorded and ive missed the last 2 minutes.Im gonna use the basic 10 minutes before,10 minutes after manual input recording method.
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I notice that regularly and it's almost always the programs that run early or late. In fact I think several channels deliberately "slide" the program timings to make you go to their online "catch-up" services. Or to mess you up if you want to catch the start of something on another channel. >:D
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That's the theory, robinsteele, and it was introduced even with Videoplus on the old analogue services. The problem is that the codes that should control the timings to cater for previous overruns, are not always updated and some services may have not signed up to the scheme. My PVR adds 2 minutes before and after the EPG times but even that's not enough some times and I think I might go to 10 mins too.
Tony
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I agree it's intensely annoying if you miss a couple of minutes at the end of a prog. I assume the time signal for switching on the next prog must also act as an "off switch" for the current prog which is rather annoying.
However with some PVRs if you move away from the standard setting and add minutes "fore and aft" as you suggest the PVR will no longer time shift automatically (ie if the prog is move back an hour or re-scheduled to another day you still end up recording the original time period and not the prog you wanted). It may be worth checking your manual before deciding on the best way out.
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If only ITV Digital could find a backer and make a return.Ive still got my original card,an elvis programmer and the MKF software,oh and the box :lol:
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I've got a Topfield PVR, and after two attempts at retuning I'm a little concerned that I might lose some channels. Dave and Dave+1 appeared at channels 1006 and 1008, but there is a message superimposed on the screen saying that they are relocated lower down, so I should retune. However, after two rescans, they are still stubbornly at 1006/8. Doing the same on my TV set (which has its own Freeview tuner) results in those channels being relocated as they should be, so I fear that the Toppy will lose them.
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Eric your Topfield is suffering from the NIT problem I suspect, this is very similar to the scenario that I have with my set top box. I'd contact the support for your PVR and see when they are releasing an update to fix it.
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Thanks Stuart :)
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And also keep a regular watch on http://www.dtg.org.uk/retailer/download_schedule.pl for over air updates.
Tony
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Thanks for that link Tony. It led me to a downloadable upgrade which is supposed to fix the problem.
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Glad to be able to help
Tony
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Just to let you know that the upgrade was successful. The procedure for upgrading via a PC and a downloaded file is a bit tortuous, and you have to follow every detail in the instructions, but it worked. A rescan after the upgrade located all the channels at their correct positions.
So thanks again for the help.
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Glad it worked Eric, I will probably have to do the same (with the PC) if they don't broadcast an over air download before March 25th. when Rowridge channels change. Until then I shan't rescan.
Tony
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Just to report that I've successfully upgraded my Digihome PVR80, a Vestel produced machine, using a laptop and a downloaded bin file of the latest software (5.7). As Eric has previously said it's a bit torturous but OK if you follow the instructions. Now I'm already for the 25th. March Rowridge channel changes.
Tony
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Excellent :)
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Is itv4+1 on the go yet.I can get dave+1 on my two boxes,but aint found that yet.
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I just did a rescan on my PC TV card, and there's no sign of ITV4+1 here.
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I just did a rescan on my PC TV card, and there's no sign of ITV4+1 here.
Cheers,im sure i seen the other day,while watching itv4,that they said something about it and mentioned on freeview channel 118.
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Kitz. I have made a link to your forum with my bit on Split NITs in this thread on uk.tech.digital-tv where there are questions after the channel changes on Rowridge transmitter today. I hope you have no objection and it might generate a bit of traffic and, who knows, some might register to learn more about ADSL.
Tony
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Links from other forums are OK so long as they don't generate overwhelming amounts of traffic. Google searches find this forum quite readily, and 'digital tv tuning' leads to this thread not very far down the list of hits.
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I wouldn't have thought my posting would lead to too much traffic. I've just looked back at the newsgroup and there's been only one posting referring to my posting with no indication that the link has been used at all so perhaps I don't have to go to the NC!
Tony
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I think you're safe from the NC. We have far more deserving candidates. :lol: