I'm somewhat surprised the Gloucestershire MUX is completely absent from this listing - IIRC from the earlier maps, there were quite a few additional sites planned for the Cotswold valleys and the Forest of Dean.
Of course, those are the areas where BBC Radio Gloucestershire (uniquely I think) re-opened AM services because FM was poor, and this plan is about adopting FM equivalence...
Subject to further technical analysis, across the
UK the stations which BBC management would expect to continue to transmit in
Medium Wave include Radio 5 Live, BBC Asian Network, BBC Radio Jersey, BBC
Radio Guernsey, BBC Gloucester, BBC Derby, Radio Scotland, Radio Wales and
Radio Ulster/Foyle
I'm also surprised about the lack of London mux improvements considering it was a bit more in depth than that on the first report that was published which also included coverage maps in...2011?
Having said that it did sound as though the extra transmitters and work for London were the last phase (Phase 3) which probably won't be published in a detailed listing such as this at the moment. I mean, that's enough to be getting on with there.
I don't think Stage 1 and Stage 2 directly tally with any Phase in the buildout plans. Seems to be a cherry-picked hybrid version of Phase 2 and 3.
London will require works, at least for London III as this is required for Sussex. Unless they have switched Sussex to 10B instead of London III which was planned, but I'd be surprised given planning with neighbouring multiplexes.
The document does say that the list is not definitive and final. That some additional works may take place given subsequent spectrum analysis etc. Therefore that doesn't rule out changes to London.
Interesting to see they're putting the Bournemouth mux on Bincombe. I'd always thought a new mux would be created for Weymouth and Dorchester, but it seems not. (Maybe I missed an announcement.)
I wonder where that leaves Wessex FM.
The area was originally allocated 12A but it was never advertised. It think it makes more sense for it to be an extension of Bournemouth as the population is too small to support it's own MUX.
It seems a bit ridiculous that Wirral is not included in the BBC expansion. It would probably be served ok with St John's Beacon but the BBC National is the ONLY one that is not due to be on this transmitter.
As a result, we will still have almost non existent and blotchy reception in Birkenhead which gets part signal from Moel Y Parc and part from Winter Hill. The centre of Birkenhead is slap bang in between and is not covered properly.
Thanks, but that is the one I used. What is the advantage of dbw over watts and kilowatts, or is it just a new ISO standard?
The advantage is that when you quote a dBW (or dBm for dB relative to 1 milliWatt for my profession, cellular) then if you have the antenna horizontal radiation pattern available e.g. via Ofcom's TX txparams, and know your bearing relative to the TX, you can very quickly calculate the dBW power value radiated in your direction via a direct subtraction. The quoted dBW values will be peak forward power, i.e. at the maximum forward gain orientation of the transmitting antenna.
Sure you can start out from a quoted value in Watts, but you're never quite sure whether the bloke doing the quoting has remembered to add the TX forward gain to get ERP, or whether that's just the power at the end of the feeder. Using dBW makes it unambiguous, and in any case to do anything with a value in Watts you have to convert it to a log at some stage anyway.
The advantage is that when you quote a dBW (or dBm for dB relative to 1 milliWatt for my profession, cellular) then if you have the antenna horizontal radiation pattern available e.g. via Ofcom's TX txparams, and know your bearing relative to the TX, you can very quickly calculate the dBW power value radiated in your direction via a direct subtraction. The quoted dBW values will be peak forward power, i.e. at the maximum forward gain orientation of the transmitting antenna.
Sure you can start out from a quoted value in Watts, but you're never quite sure whether the bloke doing the quoting has remembered to add the TX forward gain to get ERP, or whether that's just the power at the end of the feeder. Using dBW makes it unambiguous, and in any case to do anything with a value in Watts you have to convert it to a log at some stage anyway.
OK well I managed to change from imperial to metric so may as well get used to it.
Anyway looking at that that list I should get a good signal from Llangollen (really strong on FM here) and maybe the Liverpool service from Winter Hill. So a bit more choice.
Although Manchester gets a couple more transmitters nothing is being done about the fact that since the closure of the Regional multiplex transmitters the Manchester Multiplex is full to burst, surely a second local Multiplex would be of more value to a large catchment area.
Why on earth is North Hessary Tor being added for Cornwall?!
IIRC Cornwall and Plymouth are under the same DAB licence but are two different muxes - perhaps someone fat-fingered at Ofcom/Arqiva?
(do these new transmitters relay from an existing one and not get their own feed? Perhaps they're doing Cornwall because it is transmitted from Caradon Hill and is a lot easier to receive than Plympton for Plymouth? totally uninformed speculation, of course)
Interesting to see that a good number of relays are planned for Cornwall though. I've never had any complaints about the reception (even in car) but I live within LOS of Caradon Hill anyway (and can get Plymouth with a good aerial)
Essex to get a boost. Yes! ☺ The local DAB is shocking in Central Essex and Chelmsford. The modification on Bakers Wood and the addition of Great Braxted will be brilliant. Also, where is Whestley Heights, one of the new transmitters?
In parts of Cornwall North Hessary Tor transmitter is a better signal than the Caradon Hill. Places like West Looe where the Caradon Hill transmitter is behind the hills and Plymouth and North Hessary Tor looking towards Devon is straight across the water!
(do these new transmitters relay from an existing one and not get their own feed? Perhaps they're doing Cornwall because it is transmitted from Caradon Hill and is a lot easier to receive than Plympton for Plymouth? totally uninformed speculation, of course)
My understanding is that it would be incredibly difficult to have DAB relays (other than in-shop ones) if they're operating on the same channel. There'd be the major issue of the output aerial feeding signal back into the input aerial in an endless loop.
Even if they're on a different channel, there'd be adjacent channel interference to some degree.
Now that I have digital radio in the car it's amazing the amount of time it drops out whilst driving around locally in falkirk area. Still not up to the standard you'd expect
I can't see how relays could work with DAB but I'm not an engineer.
The BBC conducted tests for an 'on channel' DAB relay at Mapperley Ridge about 10 years ago. It's all rather tricky to set up and align, and I don't think it has ever been used
in anger ?
Now that I have digital radio in the car it's amazing the amount of time it drops out whilst driving around locally in falkirk area. Still not up to the standard you'd expect
Coverage will be boosted in line with the equivalent FM coverage of each area's largest commercial radio operator.
Coverage will increase from an average of 72% to 90% (in some areas more, others less). But some DAB sites will not go live until a radio DSO is announced, the target is 50% listening and is currently at 38% so may be some time yet. (Unless Suzi Perry's radio ads made a big switch?)
In the event that the Government announces a digital radio switchover date, additional local DAB transmitters will be launched within 12 months of the switchover date, further boosting coverage.
Coverage will increase from an average of 72% to 90% (in some areas more, others less). But some DAB sites will not go live until a radio DSO is announced, the target is 50% listening and is currently at 38% so may be some time yet. (Unless Suzi Perry's radio ads made a big switch?)
In November 2013 shadow culture minister Helen Goodman suggested this should be increased to 75% (including 50% DAB). I don't think there will be any switchover announcement before 2020:
There could be some objections to making it 75% especially set makers ( but many may agree)
I expect some BBC, Bauer and Global local stations and Absolute will soon close on AM, R4 LW 2020 and a FM switch off target date of large stations maybe 2022 assuming digital radio listening continues to grow slowly?
My understanding is that it would be incredibly difficult to have DAB relays (other than in-shop ones) if they're operating on the same channel. There'd be the major issue of the output aerial feeding signal back into the input aerial in an endless loop.
Even if they're on a different channel, there'd be adjacent channel interference to some degree.
Transmitters are either line fed or satellite fed.
Timing is critical though, with the use of GPS to ensure consistency. If timing is out on one tx, it'll punch a massive hole in coverage.
I can't see how relays could work with DAB but I'm not an engineer.
Hmm maybe. Perhaps getting the necessary leased line to NHT is expensive/hard (it's somewhat remote and currently only really does BBC FM plus a tiny TV relay) but they can send the Cornwall mux to it over microwave, or something (as NHT and Caradon Hill have line of sight, if I remember correctly)? Again, total speculation.
Similar bodges have happened, for example Barnstaple/North Devon which doesn't get its own mux, but simply what was the Exeter and Torbay multiplex
Essex to get a boost. Yes! ☺ The local DAB is shocking in Central Essex and Chelmsford. The modification on Bakers Wood and the addition of Great Braxted will be brilliant. Also, where is Whestley Heights, one of the new transmitters?
Westley Heights is just to the west of Basildon, roughly equidistant from the A127 and A13. I guess it's intended to cover those A-road and the bits of west Basildon uncovered at indoor level by the Benfleet TX. As you travel eastwards on the A127 and look SE a mile or so before Basildon, you can see the mast poking out of a hilltop thicket. OT, but Westley Heights/Langdon Hills is not a bad place for a Sunday stroll and pint, amazing considering it's next door to Bas-vegas.
Great Braxted will help enormously, not just locally but all over central Essex and down into the Dengie peninsula. Depending on what the 'DB' is relative to, the transmit array 'STAGGERED_DIPOLES_13DB' is at least 6 co-phased dipoles. Such an antenna is an enormous beastie at the Band III wavelength of 1.5m, probably about 6 to 7m in length, and will have to be delivered to site and erected as a unit due to the critical length cabling - no mean feat.
Ofcom reckoned they achieved about 100W erp with a recent DAB OCR demo at Baldock. Considering that most local TXs are in the 250W to 2kW erp bracket this is a very useful power level to have achieved, and ideal for singe-town coverage holes.
Hmm maybe. Perhaps getting the necessary leased line to NHT is expensive/hard (it's somewhat remote and currently only really does BBC FM plus a tiny TV relay) but they can send the Cornwall mux to it over microwave, or something (as NHT and Caradon Hill have line of sight, if I remember correctly)? Again, total speculation.
Some local muxes are delivered by a ring of microwave links (so if you lose one link, you've got redundancy in the other direction). As you say, Caradon and NHT are easy
line of sight with each other. I suspect NHT will simply be fed by microwave from Caradon.
On the subject of the South Hampshire mux, there was one proposal to use Hannington, to give a nice solid lump of coverage along the A303 corridor. It would also have served out of area Basingstoke, and actually a big chunk of North Hampshire, so presumably abandoned due to that being the N Hants/Berks area. A pity, it would have been nice to have the S Hants mux here in Basingstoke
Not a relay as such, I don't think. I believe there are split ads on that frequency.
Yes, there might be. You're quite right though, not a relay (I had BBC national FM in my mind ), And I've just remembered there's an audio delay between that and Bincombe Hill when the RDS flips between the two.
Comments
http://downloads.bbc.co.uk/aboutthebbc/reports/pdf/dqf_detailedproposals.pdf http://www.bbc.co.uk/news/world-europe-guernsey-12932345
I don't think Stage 1 and Stage 2 directly tally with any Phase in the buildout plans. Seems to be a cherry-picked hybrid version of Phase 2 and 3.
London will require works, at least for London III as this is required for Sussex. Unless they have switched Sussex to 10B instead of London III which was planned, but I'd be surprised given planning with neighbouring multiplexes.
The document does say that the list is not definitive and final. That some additional works may take place given subsequent spectrum analysis etc. Therefore that doesn't rule out changes to London.
Time will tell, in the next 18 months.
As a result, we will still have almost non existent and blotchy reception in Birkenhead which gets part signal from Moel Y Parc and part from Winter Hill. The centre of Birkenhead is slap bang in between and is not covered properly.
Thanks, but that is the one I used. What is the advantage of dbw over watts and kilowatts, or is it just a new ISO standard?
Sure you can start out from a quoted value in Watts, but you're never quite sure whether the bloke doing the quoting has remembered to add the TX forward gain to get ERP, or whether that's just the power at the end of the feeder. Using dBW makes it unambiguous, and in any case to do anything with a value in Watts you have to convert it to a log at some stage anyway.
OK well I managed to change from imperial to metric so may as well get used to it.
Anyway looking at that that list I should get a good signal from Llangollen (really strong on FM here) and maybe the Liverpool service from Winter Hill. So a bit more choice.
IIRC Cornwall and Plymouth are under the same DAB licence but are two different muxes - perhaps someone fat-fingered at Ofcom/Arqiva?
(do these new transmitters relay from an existing one and not get their own feed? Perhaps they're doing Cornwall because it is transmitted from Caradon Hill and is a lot easier to receive than Plympton for Plymouth? totally uninformed speculation, of course)
Interesting to see that a good number of relays are planned for Cornwall though. I've never had any complaints about the reception (even in car) but I live within LOS of Caradon Hill anyway (and can get Plymouth with a good aerial)
Even if they're on a different channel, there'd be adjacent channel interference to some degree.
Timing is critical though, with the use of GPS to ensure consistency. If timing is out on one tx, it'll punch a massive hole in coverage.
I can't see how relays could work with DAB but I'm not an engineer.
The BBC conducted tests for an 'on channel' DAB relay at Mapperley Ridge about 10 years ago. It's all rather tricky to set up and align, and I don't think it has ever been used
in anger ?
http://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP120.pdf
In November 2013 shadow culture minister Helen Goodman suggested this should be increased to 75% (including 50% DAB). I don't think there will be any switchover announcement before 2020:
http://www.theguardian.com/media/2013/nov/28/analogue-digital-radio-switch-hit-poor
I expect some BBC, Bauer and Global local stations and Absolute will soon close on AM, R4 LW 2020 and a FM switch off target date of large stations maybe 2022 assuming digital radio listening continues to grow slowly?
Hmm maybe. Perhaps getting the necessary leased line to NHT is expensive/hard (it's somewhat remote and currently only really does BBC FM plus a tiny TV relay) but they can send the Cornwall mux to it over microwave, or something (as NHT and Caradon Hill have line of sight, if I remember correctly)? Again, total speculation.
Similar bodges have happened, for example Barnstaple/North Devon which doesn't get its own mux, but simply what was the Exeter and Torbay multiplex
Great Braxted will help enormously, not just locally but all over central Essex and down into the Dengie peninsula. Depending on what the 'DB' is relative to, the transmit array 'STAGGERED_DIPOLES_13DB' is at least 6 co-phased dipoles. Such an antenna is an enormous beastie at the Band III wavelength of 1.5m, probably about 6 to 7m in length, and will have to be delivered to site and erected as a unit due to the critical length cabling - no mean feat.
Ofcom reckoned they achieved about 100W erp with a recent DAB OCR demo at Baldock. Considering that most local TXs are in the 250W to 2kW erp bracket this is a very useful power level to have achieved, and ideal for singe-town coverage holes.
Some local muxes are delivered by a ring of microwave links (so if you lose one link, you've got redundancy in the other direction). As you say, Caradon and NHT are easy
line of sight with each other. I suspect NHT will simply be fed by microwave from Caradon.
On the subject of the South Hampshire mux, there was one proposal to use Hannington, to give a nice solid lump of coverage along the A303 corridor. It would also have served out of area Basingstoke, and actually a big chunk of North Hampshire, so presumably abandoned due to that being the N Hants/Berks area. A pity, it would have been nice to have the S Hants mux here in Basingstoke
Yes, there might be. You're quite right though, not a relay (I had BBC national FM in my mind