Reception from NI in Trim

PauloMN

Apologies if this is covered already somewhere else, I couldn't find it. Just wondering what the reception of NI transmissions is like in Trim, Co. Meath. I see a lot of UHF antennas directed towards (I presume) Divis, and in most cases a smaller contract antenna pointed roughly the same direction for reception of RTÉ etc. (again I presume) from Clermont Carn.

How is the analogue reception of BBC/ITV there, and has anyone received digital there?

coylemj

From Trim Camlough and Divis are inline so it's more likely those people are receiving from Camlough. What gives it away is the alignment of the aerial, Camlough is vertical polarity while Divis is horizontal.

If you don't get a response here about reception your best bet is to probably knock on a few doors and ask.

mrdtv

coylemj wrote: »

From Trim Camlough and Divis are inline so it's more likely those people are receiving from Camlough. What gives it away is the alignment of the aerial, Camlough is vertical polarity while Divis is horizontal.

If you don't get a response here about reception your best bet is to probably knock on a few doors and ask.

Exactly. Find out if they are receiving Channel 5 analogue or Freeview: if they are its Divis! If not go for Freesat which is a very good UK FTA solution.

pg555

The analogue reception in Navan is just OK with a 10 yr old wideband ariel. I can currently reveive patchy digital from Divis on CH26 only.

lucernarian

Most people get Divis in Trim. If you go there, it's not hard to tell the polarity of those large hirschmann aerials.

Also, Camlough has slightly worse coverage than Divis except in parts of Dundalk and worse, it's wiped out by whatever DTT channels are broadcasting from Kippure/Three Rock.

And if you go for Camlough, the powerful C/D masthead amp needed will be overloaded by the much stronger (and in same direction) Clermont Carn. The signal strength difference is around 20dB and Camlough has a lower transmitter which is more obscured by the hills/Slieve Gullion in the area.

PauloMN

Thanks for the feedback all. I was there the other day and took a look at some of the aerials - they are horizontal so Divis makes sense. According to this:
http://www.bbc.co.uk/reception/transmitters/tv/tv_divis.shtml

Camlough is only around 600 watts as opposed to the 500kW from Divis, so I guess Camlough covers a relatively local area compared with Divis.

coylemj

PauloMN wrote: »

Camlough is only around 600 watts as opposed to the 500kW from Divis, so I guess Camlough covers a relatively local area compared with Divis.

Correct! I misread the power number as Kw so it's only a relay station for the folk in Newry, it's not a main transmitter so of little or no interest to us down south.

FREETV

HI, I know people living in Trim who are receiving ok reception of UTV, BBC1,2, CH4 in Analogue and Freeview sometimes in good weather but usually only the BBC Mux. The aerials are pointing in a south westerly direction but they cannot tell me the name of the Transmitter. Could it be Divis I wonder?

fat-tony

FREETV wrote: »

HI, I know people living in Trim who are receiving ok reception of UTV, BBC1,2, CH4 in Analogue and Freeview sometimes in good weather but usually only the BBC Mux. The aerials are pointing in a south westerly direction but they cannot tell me the name of the Transmitter. Could it be Divis I wonder?

Divis is in the opposite direction - North or maybe North East

coylemj

SW from Trim is looking down to Offaly and Nth Tipperary where there are no TV transmitters, certainly none transmitting BBC & ITV anyway!

Divis is 23 degrees true (NNE) from Trim, that's most likely what they're picking up but there's no digital, NI isn't scheduled for DTT until 2012.

fat-tony

Freeview is certainly available on Divis, but at low power (2Kw). Doesn't go analogue switch off (and thus full power digital) until 2013.

PauloMN

I thought there was digital from Divis, but low power until the switchover:
http://www.ofcom.org.uk/static/reception_advice/dtt_pocket_guide_4_1.pdf

Whether any digital can be received in Trim is something I'm interested in. I guess reasonable analogue can be judging by the amount of houses with UHF aerials pointed that way.

coylemj

Apologies, I wasn't aware that Divis was testing Freeview but if it's low power then I doubt if it's being picked up in Trim which is 128 kms away.

PauloMN

Yes that's what I was wondering. The analogue transmitters are 500kW, the digital only 2 or 3kW, for the moment anyway. I can't see the planned full output power for them once switched over though.

fat-tony

coylemj wrote: »

Apologies, I wasn't aware that Divis was testing Freeview but if it's low power then I doubt if it's being picked up in Trim which is 128 kms away.

It's not testing Freeview - it's had it since Freeview began, but at low power.

coylemj

That's splitting hairs, I meant a test transmission of Freeview. If they're still blasting out 500 Kw of analogue than I'd respectfully submit that the Freeview signal at 2 Kw is a 'test'.

fat-tony

coylemj wrote: »

That's splitting hairs, I meant a test transmission of Freeview. If they're still blasting out 500 Kw of analogue than I'd respectfully submit that the Freeview signal at 2 Kw is a 'test'.

Freeview launched 2002 in NI. I'm not "splitting hairs". The reduced power on digital is to protect analogue signals until analogue switch off. The DTT service in RoI, on the other hand, is a "test" because the engineers are playing around with the settings.

polyfusion

FREETV wrote: »

The aerials are pointing in a south westerly direction but they cannot tell me the name of the Transmitter. Could it be Divis I wonder?

The aerials are probably "pointing" the opposite direction; it only "appears" they are pointing south westerly, because the arrow-shape of an aerial appears to be pointing that direction.

fat-tony

polyfusion wrote: »

The aerials are probably "pointing" the opposite direction; it only "appears" they are pointing south westerly, because the arrow-shape of an aerial appears to be pointing that direction.

But the arrow shape does point towards the transmitter, which in this case is NNE, not SW.

FREETV

fat-tony wrote: »

But the arrow shape does point towards the transmitter, which in this case is NNE, not SW.

I see, my Brother owns a house there so he told me this evening about the south westerly direction. A compass would be needed I assume to find out the direction. Is there a website that can tell one the coordinates or bearings of UK Transmitters so that the correct transmitters can be found using a compass?

coylemj

Yes there is.. http://www.bbc.co.uk/reception/transmitters/tv/index.shtml

The GB transmitters are given as OSGB grid references, in the case of the NI transmitters they are Irish grid references.

I have the NI and Welsh transmitter locations stored in a Garmin Mapsource digital map so can give you distance and bearing from anywhere to any of those transmitters, that's how I was able to give the exact bearing from Trim to Divis in my earlier post.

polyfusion

fat-tony wrote: »

But the arrow shape does point towards the transmitter, which in this case is NNE, not SW.

That arrow isn't a physical part of the aerial; I would have thought it's detachment from the obvious aerial and labelling would clearly indicate that the arrow is to show in which direction the transmitter is.

Maybe not the best example of a picture I could have posted, but it's late, and the picture was one of the first in a google search.

Taking a more typical representation of an aerial you're likely to see, in the following picture, the transmitter should be to the right, and if you want to be pedantic about it, since the observer is relatively close to the aerial as it's possible to see individual components of the aerial, behind the observer of that picture.



The "arrow" (the reflector) in that picture is pointing to the left though, making it look like maybe it should be pointing to a transmitter to the left.

FREETV

coylemj wrote: »

Yes there is.. http://www.bbc.co.uk/reception/transmitters/tv/index.shtml

The GB transmitters are given as OSGB grid references, in the case of the NI transmitters they are Irish grid references.

I have the NI and Welsh transmitter locations stored in a Garmin Mapsource digital map so can give you distance and bearing from anywhere to any of those transmitters, that's how I was able to give the exact bearing from Trim to Divis in my earlier post.

Excellent, it's good to know that there are helpful people like yourself still out there. I would love the bearings for the Welsh transmitters and Divis from Here in Swords and from Trim to Divis for my Bro. Thanks again.

mrdtv

DTT began operationally in N Ireland in 1998 in the ITVdigital era. The transmissions are only from the three main sites, Divis, Brougher Mountain & Limavady. They have always been low powered because of a shortage of available UHF channels due to proximity to ROI, Scotland and the IOM. Freeview took over in 2002 when ITVDigital collapsed. The highest DTT transmissions are currently 2.3kW compared to analogue PAL ERP of 500kW. Because of these low power DTT transmissions Freeview only covers about 58% of Northern Ireland which is also why the overspill is limited into ROI. In addition Divis DTT current channels are cochannel on some muxes with Three Rock which limits reception along the East Coast.

DSO works have just started at Divis I am reliably informed. A new taller mast is to be constructed at Divis which has recently received planning permission assents from Belfast City Council. Divis DSO will transmit 100kW ERP omnidirectional on the PSB multiplexes (equivalent to the analogue ERP of 500kW) and 50kW ERP IIRC on the COM multiplexes which are cochannel with Three Rock analogue but not Three Rock Digital. Both Limavady and Brougher Mountain will be 20kW ERP (equivalent to their current analogue 100kW ERPs). These stations will transmit all six Freeview muxes including HD from 2012.
The relay stations in N Ireland will all be converted to three mux PSB working including HD: this means that the Kilkeel relay which serves the East Coast down to Dublin will go digital in 2012.

For ROI viewers it means that those who are getting good or passable analogue signals should get excellent NI DTT including HD with the right equipment. By 2012 the price of Freeview HD receivers will fall considerably making it very attractive.

This change replicates the current situation unfolding in the South East where those who had good or passable analogue Welsh services off-air are starting to get very good digital services from Arfon, Preseli, possibly Llanddona where the changeover is underway right now. In March 2010 Blaen-Plwyf will be converted to high power DTT operating at 40kw, with a 9dB restriction in a narrow arc towards Arklow reducing ERP to 5kw. Note however that new Arfon DTT is now being received in Wicklow very well at 2kW ERP. Therefore by next spring it will be very clear in every sense of that word exactly what the degree of DTT overspill is in the South East and possibly Dublin from Wales.

Digifriendly

mrdtv wrote: »

DTT began operationally in N Ireland in 1998 in the ITVdigital era. The transmissions are only from the three main sites, Divis, Brougher Mountain & Limavady. They have always been low powered because of a shortage of available UHF channels due to proximity to ROI, Scotland and the IOM. Freeview took over in 2002 when ITVDigital collapsed. The highest DTT transmissions are currently 2.3kW compared to analogue PAL ERP of 500kW. Because of these low power DTT transmissions Freeview only covers about 58% of Northern Ireland which is also why the overspill is limited into ROI. In addition Divis DTT current channels are cochannel on some muxes with Three Rock which limits reception along the East Coast.

DSO works have just started at Divis I am reliably informed. A new taller mast is to be constructed at Divis which has recently received planning permission assents from Belfast City Council. Divis DSO will transmit 100kW ERP omnidirectional on the PSB multiplexes (equivalent to the analogue ERP of 500kW) and 50kW ERP IIRC on the COM multiplexes which are cochannel with Three Rock analogue but not Three Rock Digital. Both Limavady and Brougher Mountain will be 20kW ERP (equivalent to their current analogue 100kW ERPs). These stations will transmit all six Freeview muxes including HD from 2012.
The relay stations in N Ireland will all be converted to three mux PSB working including HD: this means that the Kilkeel relay which serves the East Coast down to Dublin will go digital in 2012.

For ROI viewers it means that those who are getting good or passable analogue signals should get excellent NI DTT including HD with the right equipment. By 2012 the price of Freeview HD receivers will fall considerably making it very attractive.

Excellent and very informative summary. I maybe wrong but think that Mux C on Ch. 48 DTT from Divis is on 3kw while all others are as you say 2.3kw. Ironically it is Mux C I have most problems with though I am only about 15 miles as crow flies from Divis. I have a wideband aerial which struggles higher up the frequencies and also due to foliage in summer I get occasional breakup but all the other multiplexes come through without any difficulties. As you say after DSO, Freeview should be easily picked up in much of ROI where analogue is now received.

mrdtv

Digifriendly wrote: »

Excellent and very informative summary. I maybe wrong but think that Mux C on Ch. 48 DTT from Divis is on 3kw while all others are as you say 2.3kw. Ironically it is Mux C I have most problems with though I am only about 15 miles as crow flies from Divis. I have a wideband aerial which struggles higher up the frequencies and also due to foliage in summer I get occasional breakup but all the other multiplexes come through without any difficulties. As you say after DSO, Freeview should be easily picked up in much of ROI where analogue is now received.

Thanks. You are right re Mux C. There is probably CCI on Ch 48 from somewhere and wideband aeriials are not so good.

Here's another nice site with Divis stuff:

http://www.thebigtower.com/live/Divis/index.htm

dkane

I live just outside Trim. We pick up analogue from Brougher Mountain with one or two Freeview MUXs coming in if there is lift late at night.
Installers around the area would usually try both Divis and Brougher Mountain and compare the signal as both are usually fairly similar in terms of reception around here (I am talking about Analogue)

mrdtv

dkane wrote: »

I live just outside Trim. We pick up analogue from Brougher Mountain with one or two Freeview MUXs coming in if there is lift late at night.
Installers around the area would usually try both Divis and Brougher Mountain and compare the signal as both are usually fairly similar in terms of reception around here (I am talking about Analogue)

Yes, both are Group A stations. How good is the analogue?

dkane

Analogue is usually ok, never brilliant. UTV and Channel 4 loose colour from time to time, usually UTV will be the first effected.
Our aerial is not very high, maybe 2m of top of single story house but we have a fairly clear view in the direction of Brougher.

I have been threatening to get up there and swing the aerial around to Divis to see if Freeview is any better but never got around to it. View would not be as clear in that direction though.

PauloMN

Thanks for the information Daniel. Assuming a clear view, I suppose Divis would be the transmitter of choice. I'll try both though when I move.

anotherlostie

My Dad, in Cavan, had perfect analogue signal except for channel 4 which was a bit grainy, but when he got a Freeview box, it could only pick up a handful of channels, and they used to drop out frequently. So now he has Sky. If you couldn't get a decent signal in Cavan, I'd be surprised that you could in Trim.

coylemj

FREETV wrote: »

Excellent, it's good to know that there are helpful people like yourself still out there. I would love the bearings for the Welsh transmitters and Divis from Here in Swords and from Trim to Divis for my Bro. Thanks again.

All bearing are true, add 5 to convert to magnetic

Swords to Divis 6
Swords to Llanddona 96
Swords to Arfon 110
Swords to Blaenplwyf 130
Trim to Divis 23

fat-tony

polyfusion wrote: »

That arrow isn't a physical part of the aerial; I would have thought it's detachment from the obvious aerial and labelling would clearly indicate that the arrow is to show in which direction the transmitter is.

Maybe not the best example of a picture I could have posted, but it's late, and the picture was one of the first in a google search.

Taking a more typical representation of an aerial you're likely to see, in the following picture, the transmitter should be to the right, and if you want to be pedantic about it, since the observer is relatively close to the aerial as it's possible to see individual components of the aerial, behind the observer of that picture.



The "arrow" (the reflector) in that picture is pointing to the left though, making it look like maybe it should be pointing to a transmitter to the left.

I think we are cross purposes The arrow that you added to the original picture was quite clear and does show the direction of maximum received signal (ie towards the transmitter). The issue was the direction of the transmitter - North East(NE) This would have the the direction the aerials were pointed - not South West.:)

pg555

I pass through Trim every day and the majority of the ariels are pointed towards Divis (as are those in Navan). I've tried to get a digital signal from the Divis transmitter in Navan and it's unwatchable. The only effective and low cost way to receive a UK digital signal in Trim before the digital changeover is via satellite.

mrdtv

pg555 wrote: »

I pass through Trim every day and the majority of the ariels are pointed towards Divis (as are those in Navan). I've tried to get a digital signal from the Divis transmitter in Navan and it's unwatchable. The only effective and low cost way to receive a UK digital signal in Trim before the digital changeover is via satellite.

This is to be expected: the highest Divis DTT mux is 3kW ERP and Divis analogue is 500kW . Of the current DTT channels used two are co-channel with Three Rock analogue wiping them out. After DSO Divis will reuse the old analogue frequencies 21, 24, 27 at 100kW and 23, 26 and 29 at 50kw. Only one Divis COM mux will be cochannel with Three Rock if it has not turned off analogue. If you get good or respectable analogue pictures from Divis you will get perfect DTT on the same frequencies. As you say Sky or Freesat is the best solution in the interim but can be an expensive route for multiple TVs.

lucernarian

I think people are also forgetting about the proposed Navan DTT relay, which is planned to broadcast on 23, 26 and 29...

mrdtv

To_be_confirmed wrote: »

I think people are also forgetting about the proposed Navan DTT relay, which is planned to broadcast on 23, 26 and 29...

Let's see what happens with Irish DTT and its trials and tribulations. The high power Divis PSB muxes will be clear.