Is the max power of a dab transmitter 10 kw , if so how far would that get out , as far as a 250 kw on fm ?
Looking at a fairly average TX, the THV9 product line from Rohde & Schwarz, they'll be happy to sell you up to 30 kW which in this case is presumably two side-by-side 15 kW racks. As far as I've seen the Beeb and others use 1+1 arrangements, with two independent TXs driving separate antennas, ranging all the way from a couple of dipoles up to fairly mean arrays. In theory this is so that one chain can be worked on, while the site is still on half-power working on the other chain.
Unlike FM where the power is envelope ERP, DAB and other C/OFDM systems quote average power without crest factor. As with any ERP, add the cable loss, and subtract the antenna gain to obtain the power required at the TX. For the 10 kW TX sites with sizeable arrays, this is probably about 2-3 kW (mean) in the cab, feeder and connector quality dependent. This is on the border between liquid- and air-cooling, high power FM sites invariably being liquid-cooled.
Depending on who you listen to, the Digital Audio advantage over FM is between 12 and 18 dB, but this is dependent on the characteristics of the FM broadcast with which you're comparing it. So a 10 kW mean DAB signal may be more or less in reach than a 250 kW envelope power MP FM signal. In a densely-crowded region like Western Europe, with a new country every 300 km or so linear distance, forget about being able to co-ordinate anything greater than 10 kW digital between country-wide SFNs. Even 10 kW is a pretty mean feat, considering the very high sites used in the UK.
Depending on who you listen to, the Digital Audio advantage over FM is between 12 and 18 dB, but this is dependent on the characteristics of the FM broadcast with which you're comparing it. So a 10 kW mean DAB signal may be more or less in reach than a 250 kW envelope power MP FM signal. In a densely-crowded region like Western Europe, with a new country every 300 km or so linear distance, forget about being able to co-ordinate anything greater than 10 kW digital between country-wide SFNs. Even 10 kW is a pretty mean feat, considering the very high sites used in the UK.
Plus, of course, the fact that we're comparing FM on Band 2, with DAB on Band 3. In real-world conditions, wouldn't you expect a band 2 signal to be audible further away than a band 3 signal of the same ERP?
Plus, of course, the fact that we're comparing FM on Band 2, with DAB on Band 3. In real-world conditions, wouldn't you expect a band 2 signal to be audible further away than a band 3 signal of the same ERP?
And the TV DSO has left several relay masts in good order and can take extra DAB transmitters of up to 10kw, which means DAB rollout is now easier, Also with the DAB SFN any overlap between all the transmitters can add to the received signal, not waisted, making DAB more effecient.
Also with the DAB SFN any overlap between all the transmitters can add to the received signal, not waisted, making DAB more effecient.
Which is also why you'll be less likely to see many transmitters over 10kW. Often having multiple smaller transmitters is favourable over the setup of the olden days where you'd have one very high power transmitter blasting as far and wide as possible.
Which is also why you'll be less likely to see many transmitters over 10kW. Often having multiple smaller transmitters is favourable over the setup of the olden days where you'd have one very high power transmitter blasting as far and wide as possible.
AND...the original FM network was modelled (more or less) on the earlier Band 1 BBC TV transmitter plan, which was designed for fixed reception. That allows rather more tolerance of variations in received field strength, as the person receiving the signal can put up a bigger aerial, or move it, to compensate. Not an argument that works with portable radios where the expectation is it'll work everywhere. Most of the gaps were filled in later, but I'm not sure that's how you'd design the network if you were designing, from the outset, for rugged coverage.
It doesn't matter how bright a light you shine at a brick wall - the other side will be dark.
Notice only two transmitter sites are cleared for D2 in Northern Ireland, Black Mountain and Colinward, limiting reception to greater Belfast and Newtownabbey.
Notice only two transmitter sites are cleared for D2 in Northern Ireland, Black Mountain and Colinward, limiting reception to greater Belfast and Newtownabbey.
I think that's out of date. Now that Irish analogue TV on Band III has been switched off I think 11A is cleared for DAB use across NI.
The Ofcom advertisement document doesn't refer to any restrictions for NI as far as I can see, and the Cork regional 11A allocation is unaffected by the use of 11A in NI.
I think that's out of date. Now that Irish analogue TV on Band III has been switched off I think 11A is cleared for DAB use across NI.
The Ofcom advertisement document doesn't refer to any restrictions for NI as far as I can see, and the Cork regional 11A allocation is unaffected by the use of 11A in NI.
I don't think there's any reason why D2 would be restricted to Greater Belfast. I'd be surprised if they didn't use at least another two or three transmitters, probably Limavady, Brougher Mountain and Derry/Londonderry would be enough to provide significant coverage for most of the province.
Woah woah woah. There are a lot of people here that seem to be confused by Ofcom's cleared transmitter list.
The cleared transmitter list is effectively an updated version of the old Reserved Assignment List of TXs. The list is simply the TX sites where a multiplex operator is free to launch without having to worry about complying with ACI rules. There's nothing to stop D2 going on at Wrotham for example, but the TX would need to not cause ACI, and if it did then the mux operator would need to provide either a power increase or a new TX for the mux(es) being interfered with.
Even sites that are on the list must still comply with interference with France/Belgium/Ireland. So even though sites like Chillterton Down are listed, the D2 will still need to be careful with ERP and transmission pattern.
That suggests reception on the southern M25 may be disappointing because Croydon is screened by the North Downs. Originally the London muxes used Otford and Kemsing as local fillers before Wrotham finally made its very tardy appearance.
It looks like the same mistakes will be made all over again, but that's the story of DAB !
Woah woah woah. There are a lot of people here that seem to be confused by Ofcom's cleared transmitter list.
The cleared transmitter list is effectively an updated version of the old Reserved Assignment List of TXs. The list is simply the TX sites where a multiplex operator is free to launch without having to worry about complying with ACI rules. There's nothing to stop D2 going on at Wrotham for example, but the TX would need to not cause ACI, and if it did then the mux operator would need to provide either a power increase or a new TX for the mux(es) being interfered with.
Even sites that are on the list must still comply with interference with France/Belgium/Ireland. So even though sites like Chillterton Down are listed, the D2 will still need to be careful with ERP and transmission pattern.
Yep, as I understand it this is just a list of sites that a Mux operator could use without much trouble, if they wanted to.
It is not a list of sites used for D2. Not all the sites on the list will be used for D2, not all sites used for D2 will be on the list.
The company that wins the tender will decide which sites it plans to use. As there is no winner yet we don't know which sites will be used.
That suggests reception on the southern M25 may be disappointing because Croydon is screened by the North Downs. Originally the London muxes used Otford and Kemsing as local fillers before Wrotham finally made its very tardy appearance.
It looks like the same mistakes will be made all over again, but that's the story of DAB !
There are plenty of unused tranmistters on the ral where a neighbouring site was used - as you've already pointed out the London multiplexes originally used the ral sites but following negotiation (post DSO?) Switched to Wrotham.
There are plenty of unused tranmistters on the ral where a neighbouring site was used - as you've already pointed out the London multiplexes originally used the ral sites but following negotiation (post DSO?) Switched to Wrotham.
I suspect that Arqiva will get this licence and they will use the existing D1 sites. If Ofcom award it to another operator they will need deep pockets to roll out the infrastructure and there is no guarantee that D2 will be filled with stations. That's a much bigger gamble than handing it to Arqiva and letting them get on with it alongside the D1 expansion (a further 35 sites are promised for D1 by 2016).
I think that's out of date. Now that Irish analogue TV on Band III has been switched off I think 11A is cleared for DAB use across NI.
Yes, I think you're probably correct, although why didn't D1 use those two sites much earlier and yes, I am aware they weren't licenced to broadcast to NI until fairly recently due to the digital economy act ????????
As far as I know, Black mountain and Colinward are also due to be decommissioned with the local mux moving to Divis and Carnmoney Hill, though I don't think this has happened yet.
Digital One also use Divis and Carnmony Hill (rather than Black Mountain and Colinward) so it would be logical to assume Digital 2 will do the same.
I suspect that Arqiva will get this licence and they will use the existing D1 sites. If Ofcom award it to another operator they will need deep pockets to roll out the infrastructure and there is no guarantee that D2 will be filled with stations. That's a much bigger gamble than handing it to Arqiva and letting them get on with it alongside the D1 expansion (a further 35 sites are promised for D1 by 2016).
Rathet than a single operator, like the last D2 bid it could be a consortium with broadcasters as shareholders?
It's possible that European DAB operators/transmission providers VDL or Media Broadcast could also get consortiums with broadcaters and bid? VDL has the advantage it already provides transmission facilities for UTV Switchdigital and Muxco, and has a mast share arrangement with Arqiva?
Piers Collins, Director, Switchdigital London, said: “We have been very impressed with VDL’s fresh approach, value for money and desire to work with Switchdigital as a strategic partner.”
Yannick Andre-Masse, VDL’s CEO: “For VDL, the establishment of a presence in the UK digital radio transmission market represents an important strategic extension of the company’s existing FM and digital transmission network operations in France and Belgium.”
What are the chances of a country music type station returning to DAB playing a mix of old as well as new country.
I did used to listen to 3c once in a while but it 85% of the time only played new country and country from the last few years.
At times I like to listen to a mix of old and new country.
I do also like pop, 80s music and power ballads but there are now to many stations playing that sort of music and at times to many networked shows meaning the listening choice has dropped a little over the years.
What are the chances of a country music type station returning to DAB playing a mix of old as well as new country.
Country 1035/Easy could not find a format to keep country fans happy and like 3c failed.
Probably the best chance is Lee William's CMR Nashville http://www.cmrnashville.com
He has managed to get a show on the Wireless in London, but to go full time national DAB will probably need investment plus an ad sales team, but backers for Country music may not be easy to find?
Country 1035/Easy could not find a format to keep country fans happy and like 3c failed.
Probably the best chance is Lee William's CMR Nashville http://www.cmrnashville.com
He has managed to get a show on the Wireless in London, but to go full time national DAB will probably need investment plus an ad sales team, but backers for Country music may not be easy to find?
Shame for I do like to listen to Country music from time to time and have over 100 country songs on my desktop PC.
I once in a while do also listen to country music via the TuneIn radio app on my Samsumg 22inch LED smart TV in my bedroom.
I now also got the Tune In radio app on my Nexus 4 and 2012 verson of the Nexus 7
Country 1035/Easy could not find a format to keep country fans happy and like 3c failed.
Country 1035 failed not because of its format but because it had only an abysmal MW channel that was weak in the daytime and was the only London station that failed to reach the M25.
At night it was inaudible because of continental interference.
Had it secured a standard London-wide 4kW FM transmitter, the outcome might well have been very different.
Country 1035 failed not because of its format but because it had only an abysmal MW channel that was weak in the daytime and was the only London station that failed to reach the M25.
At night it was inaudible because of continental interference.
Had it secured a standard London-wide 4kW FM transmitter, the outcome might well have been very different.
Thanks
From the wiki under RTL Country 1035 was getting 250k listeners, if they had got an stereo FM frequency to keep the listeners, might have survived, but RTL's longwave Atlantic 252 was also declining, and RTL radio sadly exited the UK in 2002, selling Country 1035 to a record company who seemed did not know how to run a radio station and audiences dropped.
Perhaps with DAB and internet listening increasing, and JazzFM surviving, a niche terrestrial country station may be viable again if an investor is willing to take a risk and employ the right people to run it?
Sunshine the country station in Dublin seems to be doing well on FM and is also testing regional DAB+, so perhaps a UK DAB+ station on d2 is possible?
Country 1035 failed not because of its format but because it had only an abysmal MW channel that was weak in the daytime and was the only London station that failed to reach the M25.
At night it was inaudible because of continental interference.
Had it secured a standard London-wide 4kW FM transmitter, the outcome might well have been very different.
I think in the boom years of the mid-late 90s it could have different. However I suspect by now it would have morphed into something more mainstream – maybe it would have got to the “easy listening” format before 102.2 did.
I would like to see some specialist music services on D2 such as country. However I can only see this happening through operators using radio as a showcase for other activities – think the TeamRock model and Jazz FM in the early 2000s pre-GMG.
Comments
Unlike FM where the power is envelope ERP, DAB and other C/OFDM systems quote average power without crest factor. As with any ERP, add the cable loss, and subtract the antenna gain to obtain the power required at the TX. For the 10 kW TX sites with sizeable arrays, this is probably about 2-3 kW (mean) in the cab, feeder and connector quality dependent. This is on the border between liquid- and air-cooling, high power FM sites invariably being liquid-cooled.
Depending on who you listen to, the Digital Audio advantage over FM is between 12 and 18 dB, but this is dependent on the characteristics of the FM broadcast with which you're comparing it. So a 10 kW mean DAB signal may be more or less in reach than a 250 kW envelope power MP FM signal. In a densely-crowded region like Western Europe, with a new country every 300 km or so linear distance, forget about being able to co-ordinate anything greater than 10 kW digital between country-wide SFNs. Even 10 kW is a pretty mean feat, considering the very high sites used in the UK.
Plus, of course, the fact that we're comparing FM on Band 2, with DAB on Band 3. In real-world conditions, wouldn't you expect a band 2 signal to be audible further away than a band 3 signal of the same ERP?
Which is also why you'll be less likely to see many transmitters over 10kW. Often having multiple smaller transmitters is favourable over the setup of the olden days where you'd have one very high power transmitter blasting as far and wide as possible.
AND...the original FM network was modelled (more or less) on the earlier Band 1 BBC TV transmitter plan, which was designed for fixed reception. That allows rather more tolerance of variations in received field strength, as the person receiving the signal can put up a bigger aerial, or move it, to compensate. Not an argument that works with portable radios where the expectation is it'll work everywhere. Most of the gaps were filled in later, but I'm not sure that's how you'd design the network if you were designing, from the outset, for rugged coverage.
It doesn't matter how bright a light you shine at a brick wall - the other side will be dark.
http://www.a516digital.com/2014/07/10-things-to-know-about-digital-2-dab.html#more
I think that's out of date. Now that Irish analogue TV on Band III has been switched off I think 11A is cleared for DAB use across NI.
The Ofcom advertisement document doesn't refer to any restrictions for NI as far as I can see, and the Cork regional 11A allocation is unaffected by the use of 11A in NI.
I don't think there's any reason why D2 would be restricted to Greater Belfast. I'd be surprised if they didn't use at least another two or three transmitters, probably Limavady, Brougher Mountain and Derry/Londonderry would be enough to provide significant coverage for most of the province.
The cleared transmitter list is effectively an updated version of the old Reserved Assignment List of TXs. The list is simply the TX sites where a multiplex operator is free to launch without having to worry about complying with ACI rules. There's nothing to stop D2 going on at Wrotham for example, but the TX would need to not cause ACI, and if it did then the mux operator would need to provide either a power increase or a new TX for the mux(es) being interfered with.
Even sites that are on the list must still comply with interference with France/Belgium/Ireland. So even though sites like Chillterton Down are listed, the D2 will still need to be careful with ERP and transmission pattern.
That suggests reception on the southern M25 may be disappointing because Croydon is screened by the North Downs. Originally the London muxes used Otford and Kemsing as local fillers before Wrotham finally made its very tardy appearance.
It looks like the same mistakes will be made all over again, but that's the story of DAB !
It is not a list of sites used for D2. Not all the sites on the list will be used for D2, not all sites used for D2 will be on the list.
The company that wins the tender will decide which sites it plans to use. As there is no winner yet we don't know which sites will be used.
There are plenty of unused tranmistters on the ral where a neighbouring site was used - as you've already pointed out the London multiplexes originally used the ral sites but following negotiation (post DSO?) Switched to Wrotham.
I suspect that Arqiva will get this licence and they will use the existing D1 sites. If Ofcom award it to another operator they will need deep pockets to roll out the infrastructure and there is no guarantee that D2 will be filled with stations. That's a much bigger gamble than handing it to Arqiva and letting them get on with it alongside the D1 expansion (a further 35 sites are promised for D1 by 2016).
Yes, I think you're probably correct, although why didn't D1 use those two sites much earlier and yes, I am aware they weren't licenced to broadcast to NI until fairly recently due to the digital economy act ????????
As far as I know, Black mountain and Colinward are also due to be decommissioned with the local mux moving to Divis and Carnmoney Hill, though I don't think this has happened yet.
Digital One also use Divis and Carnmony Hill (rather than Black Mountain and Colinward) so it would be logical to assume Digital 2 will do the same.
It's possible that European DAB operators/transmission providers VDL or Media Broadcast could also get consortiums with broadcaters and bid? VDL has the advantage it already provides transmission facilities for UTV Switchdigital and Muxco, and has a mast share arrangement with Arqiva?
Wonder why the 12year contract only lasted 2 years (or perhaps we will not know) as VDL saw it as important?
http://www.vdluk.co.uk/en/news/17-0-17/press/switchdigital-appoints-vdl-as-its-new-transmission-services-provider-for-the-london-2-dab-multiplex
I did used to listen to 3c once in a while but it 85% of the time only played new country and country from the last few years.
At times I like to listen to a mix of old and new country.
I do also like pop, 80s music and power ballads but there are now to many stations playing that sort of music and at times to many networked shows meaning the listening choice has dropped a little over the years.
Darren
Probably the best chance is Lee William's CMR Nashville http://www.cmrnashville.com
He has managed to get a show on the Wireless in London, but to go full time national DAB will probably need investment plus an ad sales team, but backers for Country music may not be easy to find?
Shame for I do like to listen to Country music from time to time and have over 100 country songs on my desktop PC.
I once in a while do also listen to country music via the TuneIn radio app on my Samsumg 22inch LED smart TV in my bedroom.
I now also got the Tune In radio app on my Nexus 4 and 2012 verson of the Nexus 7
Darren
At night it was inaudible because of continental interference.
Had it secured a standard London-wide 4kW FM transmitter, the outcome might well have been very different.
From the wiki under RTL Country 1035 was getting 250k listeners, if they had got an stereo FM frequency to keep the listeners, might have survived, but RTL's longwave Atlantic 252 was also declining, and RTL radio sadly exited the UK in 2002, selling Country 1035 to a record company who seemed did not know how to run a radio station and audiences dropped.
Perhaps with DAB and internet listening increasing, and JazzFM surviving, a niche terrestrial country station may be viable again if an investor is willing to take a risk and employ the right people to run it?
Sunshine the country station in Dublin seems to be doing well on FM and is also testing regional DAB+, so perhaps a UK DAB+ station on d2 is possible?
I think in the boom years of the mid-late 90s it could have different. However I suspect by now it would have morphed into something more mainstream – maybe it would have got to the “easy listening” format before 102.2 did.
I would like to see some specialist music services on D2 such as country. However I can only see this happening through operators using radio as a showcase for other activities – think the TeamRock model and Jazz FM in the early 2000s pre-GMG.
Having another Dab Mux is just plain stupid to be honest, I don't listen to any music station on DAB.