Want to know which transmitters will carry extra Freeview HD?

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  • jj20xjj20x Posts: 2,079
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    lotrjw wrote: »
    remember the extra HD MUXs will only be on 30 transmitters anyway, so people on the other 50 main transmitters will also loose out!

    The interesting fact here is that the top 10 sites being used cover 46% of the population, adding the next 10 increases coverage to 64%, so only an additional 18%. Adding the final group of 10 extends coverage to 69%, so only an additional 5%. So the marginal benefits of adding additional sites are diminishing. Areas with relatively low population densities, such as the highlands and islands of Scotland, have been excluded.

    Also, the powers that be, won't want to upset our continental neighbours already using the 600MHz range. Many transmitter sites along the south and east coast, west Wales and bordering the Irish Republic are also excluded. Use of 600MHz in those areas will need to be co-ordinated with our neighbours.
  • jj20xjj20x Posts: 2,079
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    Winston_1 wrote: »
    Interesting. Off topic but the DAB aerial is useless as it only covers the very top of band 3. Block 5A at the very bottom of the band has been allocated for local ensembles in the UK so why are Triax and other aerial companies marketing aerials that don't cover this?

    http://en.wikipedia.org/wiki/Digital_radio_in_the_United_Kingdom

    5A isn't in use yet and that document was possibly targeted at the existing market (although even 10B to 10D would be out of range for that spec.). The flyer quotes the range as 217 - 240 MHz, their website quotes the range as 200 - 240 MHz. It's quite possible that it also covers 175MHz. It appears to be a simple omni-directional dipole, it will possibly work perfectly well for 5A and more a case of the marketing documentation needing an update than the product.
  • [Deleted User][Deleted User] Posts: 1,775
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    David (2) wrote: »
    Yep that's the new group T. I think these are only just starting to appear. For years we were told to go wideband but now everyone should have group T. If your one of the many with an old type wideband your at much higher risk of picking up 4g.

    SatCure call it Group L and have some Log Periodics on sale for this group. So it looks like the name is not adequately standardised.
  • [Deleted User][Deleted User] Posts: 1,775
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    jj20x wrote: »
    It was quite right to recommend wideband aerials when many areas had multiplexes scattered across the full UHF range. Clearly that became a problem when the 800MHz range was cleared, now those aerials will have no protection against 4G signals in that range.

    Gain on aerials does not roll off fast enough above the band to provide any significant protection against 4G. You need a filter for that. What the reduction in band does mean is that either wideband aerials of the same gain are shorter, or one the same length has higher gain. This is particularly beneficial at bottom of band where wideband aerials have always been bad.
  • jj20xjj20x Posts: 2,079
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    Winston_1 wrote: »
    Not convinced. Aerial manufacturers have previously marketed aerials that only cover part of the band 'cos that is all that is used (at the moment). Examples are FM aerials that only covered up to 100MHz that had to be replaced and all those TV aerials that did not cover ch 35 to 38.

    Yes, but for a basic dipole, gain won't fall off rapidly at the end of the quoted scale. It's easier to limit the range with multi-element models, but they wouldn't be omni-directional.

    It largely depends on the size of the dipole and the centre frequency it is designed to work on. The problem is that the tech. specs don't give that information. They do however give the dimensions, and it would appear to be centred on the 228 MHz (wavelengths of around 1.3 metres). That's at the top end of the range used in the UK, but also gives a smaller aerial size which may be more aesthetically pleasing.

    5A would be around 1.7 metres, so would possibly benefit from a larger dipole should anyone desire a custom built dipole specifically for that channel. ;)
  • jj20xjj20x Posts: 2,079
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    OwenSmith wrote: »
    Gain on aerials does not roll off fast enough above the band to provide any significant protection against 4G. You need a filter for that. What the reduction in band does mean is that either wideband aerials of the same gain are shorter, or one the same length has higher gain. This is particularly beneficial at bottom of band where wideband aerials have always been bad.

    Yes, I know, I'm not suggesting that the aerial range limit should be used as a filter. Just that it's better not to include 4G frequencies within the aerial range if that frequency range is not going to be used for tv in that area.
  • reslfjreslfj Posts: 1,832
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    Winston_1 wrote: »
    .... The uncertainty with groups L and H is due to what will happen with the 600MHz band.

    There is very little doubt that the 600 MHz band will be used for DTT - extra spectrum or as replacement for the 700 MHz band.

    I think the GE06 process should be redone if the 700 MHz band is released - it will otherwise be to much a spectrum patchwork.

    But I think the Ofcoms of Europe still hope to avoid such a total replan of ch 21-48 around 2016/17.

    They shoul face the problems and - 'Just do it'

    Unless you need the very largest (group A) aerial - you should install a Wide60 or a ch 21-48 aerial. The extra cost of one size larger W60 aerial is next to nothing.

    Lars :)
  • [Deleted User][Deleted User] Posts: 1,775
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    Winston_1 wrote: »
    Satcure have (unusually ) made a mistake. New group L, low, coded orange is either 21-30 or 21-38. New group H, high, coded blue is either 39-60 or 31-60. New group T, total, coded white is 21-60. The uncertainty with groups L and H is due to what will happen with the 600MHz band.

    Given that everywhere in the country is using the 600Mhz channels to some degree for com7 and com8 I would have thought the Low group would be 21-38 and the High group 31-60 so that both cover the 600Mhz channels (most of which are actually below 600Mhz oddly).

    But really a High aerial 31-60 is pointless, it's going to be hardly any better than a 21-60 Total. I agree with the previous poster, we only need two groups: 21-60 for most people and something like 21-38 for those in old Group A regions that need extreme gain.
  • LinearCandidateLinearCandidate Posts: 32
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    I wonder why the Dover transmitter won't be getting these new multiplexes? :confused: Can we blame that one on the French for hogging the spectrum needed? :cool::D
  • [Deleted User][Deleted User] Posts: 1,775
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    I wonder why the Dover transmitter won't be getting these new multiplexes? :confused: Can we blame that one on the French for hogging the spectrum needed? :cool::D

    Probably a combination of the spectrum planning with the French, plus the number of households served by Dover is presumably not particularly high.
  • technologisttechnologist Posts: 13,334
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    Yes .... Spectrum coordination ... You will note that Heathfield HJV is not on the list.....
    With the arrival Of digital broadcasting Dover lost its audience .. It had more viewers than CP.
  • [Deleted User][Deleted User] Posts: 1,775
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    Yes .... Spectrum coordination ... You will note that Heathfield HJV is not on the list.....
    With the arrival Of digital broadcasting Dover lost its audience .. It had more viewers than CP.

    Presumably to have more viewers than Crystal Palace most of those viewers were in France?
  • technologisttechnologist Posts: 13,334
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    And Belgium and the Netherlands .....
  • DWA9ISDWA9IS Posts: 10,557
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    OwenSmith wrote: »
    Presumably to have more viewers than Crystal Palace most of those viewers were in France?
    And Belgium and the Netherlands .....

    lol so I guess viewers from those countries dont use the Dover transmitter now then?
  • technologisttechnologist Posts: 13,334
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    All fed by DSAT for many years now .... But still a good source of income for the BBC .
  • DWA9ISDWA9IS Posts: 10,557
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    All fed by DSAT for many years now .... But still a good source of income for the BBC .

    why did people from other counties receiving the BBC have to pay the BBC to get our domestic service? I would have thought that it wasnt possible to chase that money?
  • jj20xjj20x Posts: 2,079
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    lotrjw wrote: »
    why did people from other counties receiving the BBC have to pay the BBC to get our domestic service? I would have thought that it wasnt possible to chase that money?

    Cash from the cable networks at a guess.
  • DWA9ISDWA9IS Posts: 10,557
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    jj20x wrote: »
    Cash from the cable networks at a guess.

    Oh right I see that would make sense, viewers pay cable companies then they pay BBC!
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