Digital Switchover - UTV Region (DigitalUK)

holidaysong

Is there a reason why the RTÉ channels aren't showing for postcodes covered by Divis? Why is this transmitter not carrying them?

mrdtv2010

Mr. Rabbit wrote: »

Along the Ards peninsula I've noticed there are quite a lot of aerials for Clermont Carn, even in places such as Donaghadee, Millisle, and Ballywalter.

I would imagine the likes of Holywood and Bangor should get adequate reception from Carnmoney Hill if Black Mountain is difficult.

Newcastle could be a real blackspot.

Yes, the Ards peninsula is well served by CC. Even if there is a multipathed analogue CC picture such as at Strangford, Portaferry or in the lee of the Mournes, the post DSO CC signal will provide excellent coverage. Note that the post DSO CC signal is 32kW, not the 160kW analogue ERP but this will replicate the analogue coverage nicely as per the usual Chester arrangements for DSO conversions across Europe. Hollywood and Bangor should have coverage from both Black Mountain and Carnmoney Hill (line-of-sight) which will give the 'Gold Coast' RTE terrestrial service for the first time ever.

Newcastle will remain problematic if there is no service from Black Mountain as it is in the lee of the Mournes, shielded from Three Rock and Kippure, and in the firing line for MyP overspill. Further south at Annalong and beyond Kippure/Three Rock should be no problem although there will be CCI from Winter Hill.

mrdtv2010

holidaysong wrote: »

Is there a reason why the RTÉ channels aren't showing for postcodes covered by Divis? Why is this transmitter not carrying them?

To be transmitted from Black Mountain. It is shown on Belfast postcodes: just put in UTV or BBCNI's postcode. Its NIM in the DUK checker.

holidaysong

mrdtv2010 wrote: »

To be transmitted from Black Mountain. It is shown on Belfast postcodes: just put in UTV or BBCNI's postcode. Its NIM in the DUK checker.

Yeah, I was using an NI postcode, from Newtownhamilton, Co. Armagh. Says only Divis coverage there and nothing about Black Mountain.

Peter Rhea

mrdtv2010 wrote: »

. . . Note that the post DSO CC signal is 32kW, not the 160kW analogue ERP

Post switchover ERP of Clermont will be 160kW, according to this document.

The current analogue output is 250kW, or maybe you know different?

Mr. Rabbit

Note that the post DSO CC signal is 32kW, not the 160kW analogue ERP.

Sorry, you've lost me here. I thought Clermont Carn was 250kw analogue, and 160 kw post DSO (but restricted until the 24th October ???????):

http://www.rtenl.ie/wp-content/uploads/2011/12/SAORVIEW-Frequencies-Rev-1.0.pdf

Peter Rhea

holidaysong wrote: »

Yeah, I was using an NI postcode, from Newtownhamilton, Co. Armagh. Says only Divis coverage there and nothing about Black Mountain.

Even Divis doesn't look so hot on the Newtownhamilton postcode I tried.

Mr. Rabbit

holidaysong wrote: »

Is there a reason why the RTÉ channels aren't showing for postcodes covered by Divis? Why is this transmitter not carrying them?

UTV HD still isn't showing either when you enter an NI postcode. Only 3 HD channels post DSO, though we now know this is wrong.

Digifriendly

Mr. Rabbit wrote: »

Along the Ards peninsula I've noticed there are quite a lot of aerials for Clermont Carn, even in places such as Donaghadee, Millisle, and Ballywalter.

I would imagine the likes of Holywood and Bangor should get adequate reception from Carnmoney Hill if Black Mountain is difficult.

Newcastle could be a real blackspot.

TBH I haven't seen too many CC aerials in Donaghadee but more further down the coast. I know there is co-channel problems with receiving CC analogue in Bangor due to Whitehead transmitter but mini-mux as stated above should solve the Bangor and Holywood 'blackspots' for RTE.

ardmacha

Yeah, I was using an NI postcode, from Newtownhamilton, Co. Armagh. Says only Divis coverage there and nothing about Black Mountain.

RTÉ in those parts can be easily directly received from Clarmont Cairn, so the level of service from Divis is not important.

mrdtv2010

Current CC analogue power towards NI is 160kW, using the usual Chester rules for DSO conversions the maximum ERP would be 7dB down on analogue or 32kW. The figures published by RTENL do not give the radiation pattern. It is very unlikely that Ofcom would agree to 160kW into Northern Ireland given that post Divis DSO is only 100kW. Note that 32kW COFDM will essentially replicate a 160kW PAL signal with far superior receivability. There will still be restrictions towards the UK from CC in order not to interfere with other stations. The radiation pattern is key to understanding the power restrictions: is this in the public domain?

Peter Rhea

mrdtv2010 wrote: »

There will still be restrictions towards the UK from CC in order not to interfere with other stations. The radiation pattern is key to understanding the power restrictions: is this in the public domain?

I'd forgotten about this transmitter list, it shows directional restrictions to the north & east alright, probably the best the likes of me can access.

Mr. Rabbit

It is very unlikely that Ofcom would agree to 160kW into Northern Ireland given that post Divis DSO is only 100kW

What on Earth has that got to do with Clermont Carn ??????

Divis doesn't share any channels with Clermont Carn. You could say the same thing about any of the ROI transmitters close to the border i.e.Holywell Hill, Moville, Truskmore, and even Cairn Hill.

When I asked Saorview Brian about this he emphatically stated Clermont Carn would be on full power after the 24th October. He said nothing about any restrictions in the direction of NI post DSO.

The Cush

mrdtv2010 wrote: »

The radiation pattern is key to understanding the power restrictions: is this in the public domain?

The current Comreg broadcasting technical parameters for RTÉ/TG4 are available here - http://www.comreg.ie/_fileupload/Technical%20Parameters_20120313.xlsx

reslfj

Peter Rhea wrote: »

I'd forgotten about this transmitter list, it shows directional restrictions to the north & east alright, probably the best the likes of me can access.

This is the analogue restrictions - the digital TX antenna may and likely will be different.

Mr. Rabbit wrote: »

It is very unlikely that Ofcom would agree to 160kW into Northern Ireland given that post Divis DSO is only 100kW

What on Earth has that got to do with Clermont Carn ??????

The general principle is that you are not allowed to radiate into other countries. It is in most cases not possible to avoid some cross border transmission, but transmitting anything like 160kW with the border just 1 mile away - is way outside the rules in the GE06 agreement.

However, the MOU may well have resulted in the two administrations were told to agree and allowing more than 'normal' overspill.

The 52 dbW (160kW) Vertical is the GE06 figure for channel 52, 53, 56, 57 and 60 (plus some 800MHz channels).

Lars

marno21

RTE have stated before that DTT from Clermont currently uses a directional antenna pointing SW, and after DSO it will be transmitted from the antenna system currently used for analogue, which I presume will have the same directional restrictions as analogue.

lawhec

If current analogue power directed northwards is 160kW, then this means it is slightly less than 3db restricted against the direction of peak power, which is rated for 300kW. If the same transmitting aerial is used for DTT, then this would roughly translate into an ERP of 85kW aimed northwards. Don't have it on hand, but the directional restrictions north of Clermont Carn aren't uniform - there are some more deeper restrictions in some directions than others.

While the rule of thumb of -7db ERP for the PSB multiplexes compared to the peak ERP of analogue broadcasts is certainly true for most of the UK sites, there are some exceptions like Rowridge which was 500kW ERP Horizontal which is now 200kW ERP both Horizontal and Vertical (ertical has been added to help viewers avoid co-channel interference) and there are a number of relays whose DTT ERPs will be much higher than -7db compared to analogue e.g. Camlough from 640W analogue to 500W DTT, Carnmoney Hill 20W analogue to 16W DTT, Kilkeel 500W analogue, 400W DTT; same with Larne. Leitrim is going from 63W analogue to 200W DTT! L/Derry from 3.2kW analogue to 2kW DTT etc. there's quite a few relays that'll get effective coverage boosts post-DSO.

The -7db rule for (Republic of) Irish main transmitter sites isn't in force as much. Apart from I think Maghera, the main TX sites run at approx 500kW for analogue broadcasts where they're co-located with RTÉ1 & RTÉ2 VHF transmissions - most of the high powered sites will be running at 160kW post-DSO (Mullaghanish 200kW) while directional restrictions on Holywell Hill and Truskmore along with Clermont Carn will be lifted on 24/10. Many of the mid-powered UHF analogue sites will be getting significant comparative increases e.g. Spur Hill from 10kW analogue to 50kW DTT.

Edit: Looking at the document The Cush linked to, there's no effective ERP restrictions into Northern Ireland from Clermont Carn except for those required towards certain directions for Britain.

Peter Rhea

Peter Rhea wrote: »

I'd forgotten about this transmitter list, it shows directional restrictions to the north & east alright

Actually quite severe restriction to the north, much more than would result in 160kW output. I can only assume things have changed since October 2004 (GE06?, new mast?) or the data is incorrect.


This next list meanwhile, only shows easterly/southeasterly restrictions on the analogue transmissions (already mentioned by lawhec).

The Cush wrote: »

The current Comreg broadcasting technical parameters for RTÉ/TG4 are available here - http://www.comreg.ie/_fileupload/Technical%20Parameters_20120313.xlsx

Mr. Rabbit

Many of the mid-powered UHF analogue sites will be getting significant comparative increases e.g. Spur Hill from 10kW analogue to 50kW DTT

Or Three Rock from 25kw to 60kw.

I get the impression that ROI DTT transmitters have far higher ERPs than those in the UK. Moville for example, is 2kw whereas Carnmoney Hill is only 16w (comparing like for like). Moville will have more or less the same ERP post DSO as Divis has at present.

There must be areas in and around Dublin that will have perfectly adequate reception from Three Rock, Kippure, and even Clermont Carn and Mount Leinster.

Mr. Rabbit

which I presume will have the same directional restrictions as analogue

Why ?

Is analogue currently restricted to the north for technical or political reasons ?

I would have thought the MOU would have done away with any political problems.

The only technical reason I can think of is the Whitehead transmitter.

Richard

Mr. Rabbit wrote: »

Why ?

Is analogue currently restricted to the north for technical or political reasons ?

I would have thought the MOU would have done away with any political problems.

The only technical reason I can think of is the Whitehead transmitter.

I didn't think there were restrictions to the north any more. There were certainly some a few years ago before the changes to a transmitter (I think that was Whitehead).

And to be honest, any restrictions would have been technical ones, never political. In fact, the placement of the transmitter at CC, near the border was a political one.

Mr. Rabbit

If I remember correctly Richard, there were political objections (by certain Unionist politicians) to both Clermont Carn and Holywell Hill when they came into service, but in reality no one in the Unionist community was complaining. Looking at the number of Clermont Carn aerials in loyalist/unionist areas in East Belfast (virtually every house) and it's clear there aren't any political objections to RTE.

Wasn't the mast at Clermont Carn increased in height a few years back as well ? The analogue signal's so strong here I didn't notice any difference.

The Cush

A new DigitalUK trade update on the NImux was published on Fri last.

http://www.digitaluk.co.uk/transmitternetwork/tools__and__resources/almanac/special_editions/Special_edition-010612_NI_trade_update_on_Nimux.pdf
http://www.digitaluk.co.uk/transmitternetwork/tools__and__resources/almanac

Some points
- Multiplex name - NImux. Multiplex Broadcasting Services N. I. Limited - the RTÉ/TG4 joint venture company that will operate the mux
- "some programmes may not be broadcast owing to rights restrictions" as previously indicated in the Competition Authority's Determination
- NImux coverage 76%, Saorview NI overspill coverage 56%. Predicted combined NI coverage 93%
- Analogue TG4 from Divis to be switched off at DSO Stage 2 (24th Oct). Most should be able to receive TG4 from Black Mt after DSO, the rest may have to use satellite or cable

The Cush

This is from a DMOL response (from EPG Providers) to an Ofcom consultation on Local TV

I would note that channels broadcast from the new Northern Ireland multiplex („NImux‟) - which is expected to launch at switchover in Northern Ireland carrying TG4, RTÉ One and RTÉ Two – are not public service channels in the UK and are not listed in s.310 CA (despite their status in the Republic of Ireland). As such they will not be eligible for appropriate prominence in the DTT EPG, and would be allocated LCNs in the normal way as per the DMOL LCN Policy. Since those three channels do not appear to be associated with any existing General Entertainment channel we would expect TG4, RTÉ One and RTÉ Two to be allocated the next available LCNs at the bottom of the General Entertainment genre - as and when they make their LCN Applications to DMOL, and subject to those applications.

http://stakeholders.ofcom.org.uk/binaries/consultations/localtv/DMOL.pdf

Ronnie Raygun

Mr. Rabbit wrote: »

I get the impression that ROI DTT transmitters have far higher ERPs than those in the UK. Moville for example, is 2kw whereas Carnmoney Hill is only 16w (comparing like for like).

No way like for like, just look at the area of Derry & north Antrim that Moville is slated to cover after switchover.

I suspect a lot of the ROI txs appear to have very high DTT powers relative to analogue because the analogue output was nowhere near good enough to begin with.

Ronnie Raygun

mrdtv2010 wrote: »

Current CC analogue power towards NI is 160kW

So you know this for a fact or you're basing it on the 52 dBW (158.489 kW) GE06 DTT (wanted) allocation?

Mr. Rabbit

No way like for like, just look at the area of Derry & north Antrim that Moville is slated to cover after switchover

But I would have thought that Moville is not specifically aimed at Derry or North Antrim ?

I suspect a lot of the ROI txs appear to have very high DTT powers relative to analogue because the analogue output was nowhere near good enough to begin with

.

800 Kw analogue for Cairn Holl is a pretty high ERP, I would have thought.

In any case, my point is that why do they need 2 DTT transmitters at 60 kw and 160kw covering roughly the same area, along with overlap from Clermont Carn and Mt Leinster (both 160 kw) ?

It doesn't make any sanse to me, especially when an area like NI is served by 3 main DTT transmittters which only have ERPs of 100/50 kw, 20/10 kw, and 20/2kw and numerous very low powered relays.

mrdtv2010

The 160kW ERP figure was given to me a while back by some RTE insiders and its confirmed by actual measurements. Those restriction patterns in the ComReg document tie in nicely as commented by reslj and others. Ofcom never publish HRP patterns for transmitters in border areas as part of the negotiation process with other Administrations.

The DUK document published by the Cush whilst not explicit appears to confirm that the Black Mountain minimux is indeed horizontally polarised (as per TG4 and C5 analogue.) This makes perfect sense as Divis aerials can be reused and shows that Arqiva/RTENL have been on the case.

Ronnie Raygun

mrdtv2010 wrote: »

Those restriction patterns in the ComReg document tie in nicely ...

No, they don't tie in at all, there's no northwards restriction shown for analogue tv, the restriction is shown in an arc from 60 to 150 degrees (east/southeast as pointed out already by Lawhec & P.Rhea).

Ronnie Raygun

Mr. Rabbit wrote: »

800 Kw analogue for Cairn Holl is a pretty high ERP, I would have thought.

Cairn Hill's DTT output is the typical 20% of analogue, though. It's a poor choice to continue your argument.

In any case, my point is that why do they need 2 DTT transmitters at 60 kw and 160kw covering roughly the same area, along with overlap from Clermont Carn and Mt Leinster (both 160 kw) ?

Three Rock & Kippure are both supposedly at 63 kW.

It should be pretty obvious by now that RTENL have taken a different approach to the UK with regard to coverage from main sites (by this I mean a greater use of overlap between service areas, so a high powered site can fill gaps in its neighbours' coverage, way it seems to me anyway) & eliminating as many of the smaller ones as possible, it's the most striking aspect of the whole switchover process.