Digital Region Overlap
The old analogue TV signals provided lots of nations and regions for the public service channels, and these have large areas of overlap. Places like Yeovil, Basingstoke, Colwyn Bay, King's Lynn, York and Berwick could choose the BBC and ITV services they watched.
The old low power digital TV signals were at very low levels and reception of signals from more than one transmitter was a rare event.
All Freeview boxes automatically scan the available broadcast frequencies looking for channels, and they do this from C21 to C69. Whilst scanning, if a duplicate version of a channel is found, such as another BBC One region, they are placed in the 800-899 channel range.
The 800-899 is easy to access by pressing CH- from 1, and in most programme guides is just a single scroll up.
The transmitters in Wales also put Channel 4 on "logical channel number" 8, because the fourth position is reserved for S4/C.
Quite a few people that use the Winter Hill or Mendip transmitters (or one of the relay transmitter) will probably find that they will now have:
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What can I do about this?
There are basically three options.
OPTION 1: Live with it. If the signals are strong enough you get a few extra channels (S4/C has English subtitles). There are techniques for sorting out the channel numbers below, but any future automatic scan will restore the channels to the order you now find them in.
OPTION 2: You can clear the all of the channels from the box and manually scan for the multiplex from only one transmitter. For the details, see the transmitter pages
OPTION 3: If the Freeview box has no "manual add" option, the only technique left is to pull out the aerial, start the automatic scan and insert the aerial just before the lowest channel number appears. For example, Winter Hill this is C54.
Some Freeview boxes will show a "percentage complete" as they scan, under this scheme C21 is "0%", C22 is "2%", C42 is "42%", C54 is about "66%".
Even if you manual scan, many boxes will scan during the night for new channels and may still add channels in the 800-899 range.
jb38: I have checked the signal quality on Mux Ch21 and it is at a steady 100% with signal strength of 80%.
I have carried out a factory re-set and when I do this I get loads of extra 800 channels so had to do another manual search and all the channels tuned in no problem with the exception of the Mux Ch24 which are all grouped under Channel 0.
I can't understand why the 'flickering' problem is only appearing on STV HD. Have I posted in the wrong section re this?
Thanks for your help!
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9:14 PM
Liz Falconer: As regards to lots of extra channels in the 800 ranges, you shouldn't really have had that result if you blanked out the channels already stored, as the only other station that its possible for you to receive on a much less reliable basis is Keelylang Hill @ 35 miles away, although I would discount that as a possibility even although its indicated as such on the trade predictor. There shouldn't really be any problems with receiving Mux Ch24 either, as STV North / Ch4 / Ch5 etc are all on that multiplex.
I suggest you try carrying out a scan "without" the aerial connected, as this "will" blank the channels stored out, then re-connect the aerial and make another auto-tune scan and see what comes up.
The reason I asked you to try a factory re-set was in case anything had been corrupted whilst you were carrying out the original tuning, as I noticed that you have had some seriously bad reception problems in the past, and tuning whilst reception is erratic can cause various difficulties to spring up at a later point in time.
Another thing that concerns me is you saying that its only STV HD that's affected, so does that mean other HD channels are OK? as if they are then it could indicate either a box fault or alternatively one at the transmitter, albeit I haven't seen any complaints as yet, but will certainly make further checks elsewhere.
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jb38: I only get the 800 channels if I carry out an auto tune. When I do a manual search I get the channels at the correct signal quality but they are not in the correct order and all grouped together under Channel O.
I forgot to say that when it starts tuning it shows 10 channels as being found but at the end it shows 20 although there are only 10 listed.
I will certainly try carrying out a scan without the aerial connected as you suggest. Think I'll leave it until Monday as need a rest!
A message did come up during the scan to say that multiple channels had been found and to confirm that the area I live in is the North of Scotland. I thought it should be Highlands and Islands?
Re the flickering it is only STV HD which is affected. All the other HD and SD channels are fine.
I really, really appreciate your help.
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jb38: I forgot to say that my reception problems have been sorted with a new aerial and coax cable. The signal quality is now a consistent 100% and signal strength is between 75% and 80%
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9:42 AM
Liz Falconer: Thanks for the update, and pleased to hear everything is OK now, although I have to surmise that STV HD must be your main viewing channel and that is why it was noticed there, as if whats been done has rectified the problem then all HD channels must have been affected as they are all from the same transmitter.
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jb38: No sorry I meant my 'past' reception problems which you referred to have been sorted.
The problem with STV HD remains I'm afraid.
I do think I may have a faulty unit.
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8:43 PM
Liz Falconer: Your best policy by far is to try and make local enquires with anyone else in your area who can view HD transmissions to find out if they have noticed any problem with STV HD, if not then its likely to point to a fault with your box, as you have effectively tried all the procedures thats possible for a user to try.
I havent as yet found anyone else making a similar complaint to yourself regarding the Rumster Forrest transmitter, either on this site or another that I use, although with your area being quite small its not necessarily the case that complaints would be made via the web but possibly more to a local TV shop etc.
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2:27 PM
Liz Falconer: I've had similar problems with a Humax HDR Fox T2 down here in The Midlands. Following switchover last week, my auto tune did exactly the same as yours. It told me there were multiple transmitters, but only gave me a choice of one. I then had umpteen '800' channels as well as the correct channels. Switching from SD to HD even went to the wrong HD channel.
Rightly or wrongly, I put it down to bugs in the HDR's firmware, and I doubt that any amount of factory resetting or scanning aerial-less would change a thing.
I didn't bother with manual tuning. I just deleted the '800' channels (you can select them and delete them all in one go). I was left with the proper list of channels, with their correct names and numbers, and all was well. Easy really.
Regarding the flicker on STV HD, this could be nothing to do with the reception. I think it is more likely to be an issue with the HDR not talking to your TV properly (for lots of possible reasons). My advice would be to check you have the latest firmware from Humax's web site, as they have fixed lots of bugs, including some with the HDMI interface.
HDMI is well-known for compatibility problems, especially with older TVs. My HDR wouldn't work at all with my Samsung TV until I upgraded the HDR firmware. Could you borrow a TV (or a PC monitor) of a different make to yours and see if you still get the problem? Your TV itself might even need a firmware upgrade.
Finally, just changing the V-FORMAT from 1080i to 1080p or 720p (or whatever) might be sufficient.
I don't want to offend jb38 or anyone else here, as this really is a great site, but sometimes a different kind of expertise is required. If my suggestions don't help, you might find that someone on the Humax forums can sort you out.
Good luck! And let me know how you get on.
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10:59 PM
Halifax
Another potential regional overlap issue which may crop up in September 2012,is the Bilsdale main transmitter becoming all digital 1 year from now today,Wednesday 26 September 2012 to be precise.The Bilsdale mast covers much of North Yorkshire and also parts of West,South and East Yorkshire too,and where i reside at present in Halifax,HX2 9JY postcode,there is an outside possibility that come DSO three of Bilsdale's mux's BBCA,BBCB (HD),D3+4 on 100kw maximum power could be received in my locality,maybe yes/no in relation to their 50kw maximum powered SDN,ArqA,ArqB mux's.The reason i am bringing this issue up is because a few miles away over the hill in Bradford,some households in particular the south and west of that city,have horizontally polarised external aerials pointing towards Bilsdale,thus receiving BBC1 North East & Cumbria,as well as ITV1 Tyne-Tees regional programming/adverts.
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Mark's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
Mark Fletcher: Yes, the TTTV-Yorkshire overlap has been there since the 1960s, and was especially handy when Emley Moor fell down in 1969.
I must actually do an "overlap" map showing ONLY the overlap areas, would be quite interesting.
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