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Help with Freeview across the sea to Co.Down?

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    #62
    Peter Rhea
    Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    Vince Cable wrote: »
    Moel-Y-Parc doesn't use UHF 50 . . .

    It does use 49+ and 51- offset channels which make a 'sandwich' of channel 50.
    Also I read somewhere about T2 transmissions using an 'extended carrier' mode which shifts them further into the lower adjacent channel (in this case already offset towards it).
    This might be a case of a little knowledge & all that; any interference caused is probably well within limits but I might as well join in the speculation. :)


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    #63
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    Peter Rhea wrote: »
    It does use 49+ and 51- offset channels which make a 'sandwich' of channel 50.
    Also I read somewhere about T2 transmissions using an 'extended carrier' mode which shifts them further into the lower adjacent channel (in this case already offset towards it).
    This might be a case of a little knowledge & all that; any interference caused is probably well within limits but I might as well join in the speculation. :)
    Very interesting if it wasn't all frustrating,I found the same annoying problem when I swung around to Welsh transmissions and Freeview HD was always the first to drop out,leaving SD sometimes 100% signal and S/N.
    As for aerials being a "Dark Art",I am still trying three years in to receive BBC FM and Dab stations from S Down.Perhaps paying for the services should be directly proportional to Signal strength,S/N and prop conditions.
    Thats just the "Wireless",wait until someone perfects transmitting "The worst quality HD in Europe".(From an earlier thread.Re BBC)


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    #64
    [Deleted User]
    Posts: 0 ✭ [Deleted User]


    reboot wrote: »
    As for aerials being a "Dark Art",I am still trying three years in to receive BBC FM and Dab stations from S Down.Perhaps paying for the services should be directly proportional to Signal strength,S/N and prop conditions.
    Thats just the "Wireless",wait until someone perfects transmitting "The worst quality HD in Europe".(From an earlier thread.Re BBC)
    Will this help ?
    Peter Rhea wrote:
    It does use 49+ and 51- offset channels which make a 'sandwich' of channel 50.
    Also I read somewhere about T2 transmissions using an 'extended carrier' mode which shifts them further into the lower adjacent channel (in this case already offset towards it).
    This might be a case of a little knowledge & all that; any interference caused is probably well within limits but I might as well join in the speculation.
    I hadn't thought of the offsets situation.I can see how that would make a muck of iom reception in Down.
    ch 49 afaik from presely is still on it's old low power versus ch50's hd service on 20kw's.
    There may be trouble ahead for those of us on the fringes of that tx :(

    I've itv1 hd swapped over to replace itv1 wales on my freeview hd tv and pvr.It's the london version thats broadcast and gives the london local news which is a bit unusual but in a good way.RTE 1,2 and tv3 are on numbers 6,7 and 8 respectively,just like they were in the analogue days here.
    All tv's in the house are configured that way with satellite on a back up analogue channel with a magic eye.
    All tv's are also used as radios,with the irish and uk channels making for a great mix.The eco functions on most telly's these days meaning you can turn the tv screen totally off and listen to the radio in stereo.
    I like!


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    #65
    Peter Rhea
    Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    Sam Russell wrote: »
    I think the major difference between FreeviewHD and Saorview is the use of T2 encoding. This puts more emphasis on the compactness of the coding to get more out of the transmission, and there is no free lunch. The cost is obviouly robustness of the transmission. Now I understood that the UK had chosen parametrs that allowed the same reception of the muxes for both T1/MPEG2 and T2/MPEG4. That may be true for local reception, but may not apply for Dx reception. This may be more marked for multi-path and multiple co-channel reception.

    This BBC document from the testing phase of T2 refers to marginal or 'slightly lower' differences in coverage wrt DVB-T, although the former has much greater resistance to impulse interference.

    Page 15 has a short section dealing with out of area reception.


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    #66
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    Peter Rhea wrote: »
    This BBC document from the testing phase of T2 refers to marginal or 'slightly lower' differences in coverage wrt DVB-T, although the former has much greater resistance to impulse interference.

    Page 15 has a short section dealing with out of area reception.
    Very interesting document,seems that if you have always lived in a fringe area,you always will,but now you may blame it on the fridge!
    Just to beat myself up more, I have swung round to CH 67,HD from somewhere in Wales,no amp required yet.
    Even if it is "High pressure lift",I could do with some.
    If we had ham,we could have ham and eggs,but we have no eggs.


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    #67
    [Deleted User]
    Posts: 0 ✭ [Deleted User]


    Llandonna has presely on 43 and 46 totally wrecked with me today,one of the very rare occasions that happens...speak of the devil and it shall pour forth and spit you in the face :D

    The bbc and itv muxes from there are pretuned here as a back up though and at 100% quality,60% strength at the moment.
    Hd is coming in on ch53 with some drop outs.

    kippure ch 54 is very poor to gone.


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    #68
    Peter Rhea
    Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    Peter Rhea wrote: »
    It does use 49+ and 51- offset channels which make a 'sandwich' of channel 50.
    Also I read somewhere about T2 transmissions using an 'extended carrier' mode . . .

    I don't think this should cause a problem, as the IOM HD mux isn't offset.

    The Moel-Y-Parc channels would have to be received at a much higher power.

    See here, pages 30 & 57.


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    #69
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    Peddyr wrote: »
    Technika STBHDV2010 Freeview HD Set Top Box. I've got one from Tesco for £70. it's basic to say the least and so far it's doing Irish DTT and the RTENL HD test looks great! At least at £70 it won't break the bank hopefully!

    See: http://direct.tesco.com/q/R.208-0359.aspx
    Bought the STB in Tesco today reduced to £30,did I do the right thing ,am I right in saying it will receive RTE and BBC Freeview HD?


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    #70
    Peddyr
    Registered Users Posts: 254 ✭✭Peddyr


    reboot wrote: »
    Bought the STB in Tesco today reduced to £30,did I do the right thing ,am I right in saying it will receive RTE and BBC Freeview HD?

    It will.


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    #71
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    reboot wrote: »
    Very interesting document,seems that if you have always lived in a fringe area,you always will,but now you may blame it on the fridge!
    Just to beat myself up more, I have swung round to CH 67,HD from somewhere in Wales,no amp required yet.
    Even if it is "High pressure lift",I could do with some.
    If we had ham,we could have ham and eggs,but we have no eggs.
    Sorry for the typo,I mean Ch 47 ,Arfon of course,coming in to S.Down on basic aerial,no amp,not stable of course but good strength and quality when there.
    Meanwhile IOM,similar aerial,twenty feet higher with amp,nothing on Ch 50,while SD channels 100%.Lets hope they tweek the Tx in May,or I may take up Welsh!
    I would believe C/C is going to be a major problem,Wales and Claremont Carn both on Ch 53,can't pick up Carn,which is only a short ditance away,Kippure ,no prpblem.(On 54 of course,not to confuse things,but you know what I am saying.)


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    #72
    reslfj
    Registered Users Posts: 876 ✭✭✭reslfj


    Sam Russell wrote: »
    ... The error correcting can only do so much, and the more that is crammed into the signal, the more fragile it becomes.
    If there is a significant dead time in the transmission, there is no chance of correcting the signal.

    The error correcting can do as much as the coderate and the FEC code allows. DVB-T2 with UK parameters uses time-interleave over around 20 symbols (~70 ms). With a coderate of 2/3 you must, however, receive over 2/3 of all bits.
    Sam Russell wrote: »
    I think the major difference between FreeviewHD and Saorview is the use of T2 encoding. This puts more emphasis on the compactness of the coding to get more out of the transmission, and there is no free lunch. The cost is obviously robustness of the transmission. Now I understood that the UK had chosen parameters that allowed the same reception of the muxes for both T1/MPEG2 and T2/MPEG4. That may be true for local reception, but may not apply for Dx reception. This may be more marked for multi-path and multiple co-channel reception.

    The UK DVB-T2 CR=2/3 parameter makes it slightly (~.5 dB C/N) less robust in AWGN and Ricean channels, about the same in Rayleigh/echo/multipath channels and very much more robust against impulse noise.
    The planned bitrate for the UK HD mux was 36 Mbps (CR 3/5), but this was changed to 40.2 Mbps (CR=2/3) after the BBC tests. The PSB (simulated) coverage was around 0.2% lower with this change.
    Note, the spec (D-Book and Nordig) has a requirement for a 1dB lower noise figure for DVB-T2 receivers.

    Lars smile.gif

    PS! With digital transmission the RF parameters are just one side of the picture - don't overestimate the importance of the RF side.


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    #73
    reslfj
    Registered Users Posts: 876 ✭✭✭reslfj


    The Cush wrote: »
    VHF DTT frequencies allocated at RRC-06
    DVB-T VHF Channels (7 MHz) allocated to Ireland at RRC-06
    5 (174 - 181) - IRL DTT NTH WEST, IRL DTT STH EAST
    6 (181 - 188) - IRL DTT WEST
    7 (188 - 195) - IRL DTT MIDLANDS
    8 (195 - 202) - IRL DTT EAST
    9 (202 - 209) - IRL DTT NTH EAST, IRL DTT STH WEST
    Finland got 2 DTT layers in VHF band III at GE06. The company DNA.fi is installing 2 DVB-T2 HD muxes HD1 and HD2 using these VHF channels.
    This is decribed here on page 11: http://dvb.org/news_events/dvbscene_magazine/DVB-SCENE37.pdf

    Finland has now (April 2011) agreed with Russia, Estonia and Sweden on using VHF band III spectrum for a third mux for SD.

    Lars :)

    PS! In addition Finland has 4 UHF DVB-2/MPEG-2 muxes, 1 UHF DVB-T2/MPEG-4 mux and a regional UHF DVB-T2/MPEG-4 mux around Helsinki.


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    #74
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    reslfj wrote: »
    Finland got 2 DTT layers in VHF band III at GE06. The company DNA.fi is installing 2 DVB-T2 HD muxes HD1 and HD2 using these VHF channels.
    This is decribed here on page 11: http://dvb.org/news_events/dvbscene_magazine/DVB-SCENE37.pdf

    Finland has now (April 2011) agreed with Russia, Estonia and Sweden on using VHF band III spectrum for a third mux for SD.

    Lars :)

    PS! In addition Finland has 4 UHF DVB-2/MPEG-2 muxes, 1 UHF DVB-T2/MPEG-4 mux and a regional UHF DVB-T2/MPEG-4 mux around Helsinki.
    Very interesting set of articles,seems things are far from agreed re T/T2.and even VHF.Did someone say a long time ago ,there are problems as you keep going up in frequency?
    It does seem odd that I can see the IOM,receive 100% Freeview SD,but not the HD Mux on 50?Seems work will be done on the Tx in May,which may alter things,but the future for relays may not be clear sailing for the public,this is hardly a Dx location.


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    #75
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    lawhec wrote: »
    There's been an unconfirmed (though likely to be reliable as it came from a broadcast engineer) report of DTT reception from the Winter Hill transmitter after DSO took place there earlier this year in parts of the East Down coast that had a clear view of the Irish Sea. Winter Hill serves the NW of England (Manchester, Liverpool, Blackburn, Preston etc) and parts of North Wales, so it may be worth a shot. Again propagation may prove to be a factor in reliable long-term reception.
    Moving conversation on from "Mullingar "old thread,sorry again.
    Interesting reception/prop conditions over the weekend where Winter Hill appeared to completely wipe out IOM Tx in this direction,(thanks P/R)
    Could this be the long standing reception problem this end ,where Ch 50 HD hardly ever available from IOM?and zero reception on any IOM channels while Winter Hill romped in ,except for Ch 54 Rte also there but T not T2? Looking at a relay with a powerful Tx behind it from this local,may need attenuation/filtering,or a better view of Wales?


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    #76
    lucernarian
    Registered Users Posts: 9,235 ✭✭✭lucernarian


    I was thinking about this, wouldn't Caldbeck be a better option and you wouldn't have to worry about co-channel on the COM muxes from Divis where you are? I know it's 120 miles away but it's closer than Winter Hill and is also broadcasting at a high ERP. There may well be fewer sources of Co-channel-interference, particularly for the BBC HD mux which is on Ch. 30 I think.


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    #77
    Peter Rhea
    Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    reboot wrote: »
    Winter Hill appeared to completely wipe out IOM Tx in this direction,(thanks P/R)
    Could this be the long standing reception problem this end ,where Ch 50 HD hardly ever available from IOM?and zero reception on any IOM channels

    Winter Hill shouldn't harm the IOM channels; if not the SFN factor then Llanddona would be the main suspect.


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    #78
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    Peter Rhea wrote: »
    Winter Hill shouldn't harm the IOM channels; if not the SFN factor then Llanddona would be the main suspect.
    Thanks for the helpful suggestion,looking into it.


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    #79
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    To_be_confirmed wrote: »
    I was thinking about this, wouldn't Caldbeck be a better option and you wouldn't have to worry about co-channel on the COM muxes from Divis where you are? I know it's 120 miles away but it's closer than Winter Hill and is also broadcasting at a high ERP. There may well be fewer sources of Co-channel-interference, particularly for the BBC HD mux which is on Ch. 30 I think.
    False dawns,caused by high pressure lift?
    All gone from Caldbeck,and Wales at this location,but maybe good news,work today on IOM Txs,seeing some improvement but not enough to clear my reception problems,give them time,will monitor over the next few days,Ch50 is the problem T2.


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    #80
    lucernarian
    Registered Users Posts: 9,235 ✭✭✭lucernarian


    Have you tried with a horizontally polarised Group A (or Group B at a pinch) and turned it towards Caldbeck? You won't get much with a VP aerial for the Isle of Mann.

    There's a far lower chance of interference on Ch 30 going on its allocations across the UK.


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    #81
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    To_be_confirmed wrote: »
    Have you tried with a horizontally polarised Group A (or Group B at a pinch) and turned it towards Caldbeck? You won't get much with a VP aerial for the Isle of Mann.

    There's a far lower chance of interference on Ch 30 going on its allocations across the UK.
    Thanks for the helpful suggestion,will give it a try.I was looking at Calbeck with a WB/H.


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    #82
    lucernarian
    Registered Users Posts: 9,235 ✭✭✭lucernarian


    What sort of wideband aerial? I didn't understand your earlier post, so you're saying that you have indeed tried Caldbeck once before with a correctly aligned aerial but the signal wasn't reliable due to weather?

    The fluctuations with DX reception can only be mitigated against by getting a Group A instead of a WB aerial, the increase in gain may not be enough for the more dramatic variation of reception that can happen with a transmitter 120 miles away!


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    #83
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    To_be_confirmed wrote: »
    What sort of wideband aerial? I didn't understand your earlier post, so you're saying that you have indeed tried Caldbeck once before with a correctly aligned aerial but the signal wasn't reliable due to weather?

    The fluctuations with DX reception can only be mitigated against by getting a Group A instead of a WB aerial, the increase in gain may not be enough for the more dramatic variation of reception that can happen with a transmitter 120 miles away!
    I thought the Freeview Tx site was pointing us towards WB for "Full services" although I do see group A .
    I tried a log periodic WB a few days ago,but with the lift,I was spoilt for choice.Today,after your suggestion I have tried Calbeck,with a very quick look,group A/H,not promising results.I suppose best results for stable signal should be looked for in bad weather conditions,although,not plesent work.Will try properly tomorrow.Thanks.


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    #84
    Joe7
    Closed Accounts Posts: 74 ✭✭Joe7


    By the time you're finished messing about, Kilkeel (or wherever) will be on anyway.


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    #85
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    Joe7 wrote: »
    By the time you're finished messing about, Kilkeel (or wherever) will be on anyway.
    Can't see analogue Kilkeel from this location ,but IOM is line of sight.
    Sure if it wasn't for people like me "messing about",half of Boards .ie would disappear.
    The main thing I have learned from two years looking at T/T2 reception, is that you may not expect to receive T2 transmissions from a Dx location ,even if the Freeview SD signal and quality is !00%
    Not worth spending a lot of money on rigging aerials ,or buying STB's or swanky Tv's until you are sure of your HD reception.
    Maybe that Wireless world article in 1946 ,by that Clark bloke was messing about,but he may have had the answer?
    Thanks for your input,hope Kilkeel works out.


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    #86
    lucernarian
    Registered Users Posts: 9,235 ✭✭✭lucernarian


    Can you get analogue BBC from any of the Northern Irish sites? You might have better line of sight to the Benagh relay but it's quite low-powered.


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    #87
    Peter Rhea
    Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    reboot wrote: »
    . . . work today on IOM Txs,seeing some improvement but not enough to clear my reception problems . . .

    Yes, the 'reception change' (for May 2011) appears to have taken place according to http://www.digitaluk.co.uk/postcodechecker/main/trade/bt344tj/NA/0/ocfejkq69ha7upfbs5093mfrp1


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    #88
    [Deleted User]
    Posts: 0 ✭ [Deleted User]


    Well I can tell you reboot that it's not the T2 per say thats the problem,it may be the sfn or one of the many other things mentioned here including co channel.

    Arfon is only 2kw,albeit on a very high site but much further away from Arklow than you are to the isle of man and yet it's t2 hd mux roars in to the town on a good group B aerial

    I presume you can receive BBC and UTV analogue reasonably from somewhere at your location? Which ever tx that is,when it goes live for freeview,unless the frequency planners have made an un holy mess,you will have hd then.
    Not long to wait but having a bit of fun dx'ing or any dx'ing in the meantime is no harm!


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    #89
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    Deleted User wrote: »
    Well I can tell you reboot that it's not the T2 per say thats the problem,it may be the sfn or one of the many other things mentioned here including co channel.

    Arfon is only 2kw,albeit on a very high site but much further away from Arklow than you are to the isle of man and yet it's t2 hd mux roars in to the town on a good group B aerial

    I presume you can receive BBC and UTV analogue reasonably from somewhere at your location? Which ever tx that is,when it goes live for freeview,unless the frequency planners have made an un holy mess,you will have hd then.
    Not long to wait but having a bit of fun dx'ing or any dx'ing in the meantime is no harm!
    Don't tell me I am not the only person messing about.
    Seriously though no analouge reception from two locations in the Mournes.
    The only interesting feature of the whole project is that RTE romps in on freeview,SD and HD at one location.( DVB-T a factor?)
    Seems to me that future reception of Freeview HD and Dx may not be a worthwhile hobby for a grown man if he wants to keep his marbles.
    May have to knock the idea on the head and torture myself with Dab.
    Pity Digital,like the causeway "Worth seeing,but not worth going to see"


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    #90
    reboot
    Registered Users Posts: 1,460 ✭✭✭reboot


    Peter Rhea wrote: »
    Yes, the 'reception change' (for May 2011) appears to have taken place according to http://www.digitaluk.co.uk/postcodechecker/main/trade/bt344tj/NA/0/ocfejkq69ha7upfbs5093mfrp1
    Don't see any change this end worth mentioning? do you?


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    #91
    Peter Rhea
    Banned (with Prison Access) Posts: 4,285 ✭✭✭Peter Rhea


    reboot wrote: »
    Don't see any change this end worth mentioning? do you?

    In the postcode checker?

    Well, it wasn't showing any reception for the HD mux last time I looked, now it's showing poor reception!


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