Full Freeview on the Divis (Northern Ireland) transmitter
Brian Butterworth first published this on - UK Free TV
Google Streetview | Google map | Bing map | Google Earth | 54.607,-6.009 or 54°36'24"N 6°0'34"W | BT17 0NG |
The symbol shows the location of the Divis (Northern Ireland) transmitter which serves 440,000 homes. The bright green areas shown where the signal from this transmitter is strong, dark green areas are poorer signals. Those parts shown in yellow may have interference on the same frequency from other masts.
_______
Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
DTG-12 QSPK 8K 3/4 8.0Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
Which Freeview channels does the Divis transmitter broadcast?
If you have any kind of Freeview fault, follow this Freeview reset procedure first.Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
DTG-12 QSPK 8K 3/4 8.0Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
Which BBC and ITV regional news can I watch from the Divis transmitter?
BBC Newsline 0.6m homes 2.5%
from Belfast BT2 8HQ, 1,044km northeast (51°)
to BBC Northern Ireland region - 46 masts.
Are there any self-help relays?
Chapel Fields | Transposer | Central Belfast | 61 homes |
How will the Divis (Northern Ireland) transmission frequencies change over time?
1950s-80s | 1984-97 | 1997-98 | 1998-2012 | 2012-13 | 4 Mar 2020 | ||||
VHF | A K T | A K T | A K T | K T | W T | ||||
C1 | BBCtvwaves | ||||||||
C21 | C4waves | C4waves | C4waves | +D3+4 | D3+4 | ||||
C23 | SDN | SDN | |||||||
C24 | ITVwaves | ITVwaves | ITVwaves | BBCB | BBCB | ||||
C26 | ArqA | ArqA | |||||||
C27 | BBC2waves | BBC2waves | BBC2waves | BBCA | BBCA | ||||
C29 | ArqB | ||||||||
C30 | LBT | ||||||||
C31 | BBC1waves | BBC1waves | BBC1waves | ||||||
C33 | com7 | ||||||||
C34 | com8 | ||||||||
C36 | _local | ||||||||
C48 | NIMM | NIMM | |||||||
C55tv_off | com7tv_off | ||||||||
C56tv_off | COM8tv_off |
tv_off Being removed from Freeview (for 5G use) after November 2020 / June 2022 - more
Table shows multiplexes names see this article;
green background for transmission frequencies
Notes: + and - denote 166kHz offset; aerial group are shown as A B C/D E K W T
waves denotes analogue; digital switchover was 10 Oct 12 and 24 Oct 12.
How do the old analogue and currrent digital signal levels compare?
Analogue 1-4 | 500kW | |
BBCA, D3+4, BBCB | (-7dB) 100kW | |
SDN, ARQA, ARQB | (-10dB) 50kW | |
com8 | (-16dB) 12.7kW | |
com7 | (-16.1dB) 12.4kW | |
LBT | (-20dB) 5kW | |
Mux 1*, Mux 2*, Mux A*, Mux B* | (-23.4dB) 2.3kW | |
Mux C* | (-24dB) 2kW | |
Mux D* | (-24.9dB) 1.6kW | |
NIMM | (-47dB) 10W |
Which companies have run the Channel 3 services in the Divis transmitter area
|
|
Thursday, 29 November 2012
niall burns: I have had a few thoughts:
Can you see the top of the Newcastle transmitter tower (where the radiating antennas are situated) or are they obscured by Tollymore Forest? If they are behind the trees, then this could be a cause of poor reception. How did you fare for analogue? Was the picture changing such as during high winds? This might be an indication to the effects of the trees being in the path.
If you are receiving Clermont Carn and Newcastle you will be unable to combine the feeds using a diplexer due to the channels that each transmitter uses. If you have the feeds combined using a splitter in reverse, then, whilst it can work, results can be unpredictable and could therefore be a source of poor reception on one or both transmitters - try removing it and tuning to Newcastle without Clermont Carn connected.
link to this comment |
niall burns: In answer to your original question of whether reception from Divis is possible, it isn't possible to provide an exact answer.
It might be worth looking around to see what others have done. In Dundrinne Gardens there are (November 2008) some Divis aerials.
It appears as if Slievenaslat and Castlewellan Forest might be the difficulty in your area, although this is just based on looking at a map.
Digital UK Postcode Checker doesn't reckon Divis is a possibility, although such predictors are in no way infallible and it should therefore be taken with a pinch of salt.
It may be that satellite reception is the best option. There are solutions that allow reception of Freesat and Saorsat using a larger dish and two LNBs. Can't really advise more than that; try searching the internet for information.
link to this comment |
N
niall burns1:04 PM
The analogue picture was perfect. The picture never changed during high winds, the only time it did was during a thunderstorm. I might try to turn the aerial towards divis to try. It couldn't really be any worse.
link to this comment |
niall burns: You should confirm that you are tuned to Newcastle transmitter by viewing the signal strength screen. On BBC One it should be tuned to C50, UTV is C55 and BBC One HD is C59.
Is it all three of these channels that are playing up?
Perhaps it could be a possibility (800W @ 3.7miles) that the signal level is too high going into your receiver. This can appear as too little or too poor a signal:
Freeview signals: too much of a good thing is bad for you | ukfree.tv - 10 years of independent, free digital TV advice
If you have an amplifier then it might be worth trying removing or turning it down. Or you might need some attenuation (the opposite of amplification).
The former analogue signals from Newcastle were at 1,000W each. The power of digital signals to serve the same area are -7dB of the analogue which is 200W.
The power of the signals now are 800W each which is -1dB on the analogue. So in real terms the signal is stronger than the former analogue.
You might be able to build a crude attenuator (prior to getting a proper one) by connecting only the inner core of the aerial lead by leaving the screen disconnected for a short distance (a few CM maybe). This will hopefully "loose" some signal.
link to this comment |
P
Peter Henderson2:43 PM
Newtownabbey
Dave: At Niall's location the Newcastle transmitter shouldn't be a problem post DSO at his location (literally only a few miles from the transmitter site). Whether or not the photographs on streetview were taken in 2008, he still should have no problem with the PSB multplexes from this transmitter.
There are alos numerous properties with CC aerials so Saorview shouldn't be a problem either (i.e. he shouldn't need to faff around with Saorsat).
Nial: Reception from the Newcastle transmitter should be near perfect at your location so I've no idea what's wrong. I'd check out all connections just to be sure a co ax plug hasn't come lose for example. Failing that I'd get somwone out just to see if there's something wrong outside (e.g. water ingress etc.}. You should be able to diplec CC and Newcastle at your location with no problems.
If Divis is a no no I'd go for Freesat, as Dave suggests. Freesat combined with Saorview would ive you a pretty good choice of free to air channels, in my opinion. By all means have a go at Divis, but bear in mind there's always Feesat if it doesn't work out.
link to this comment |
Peter's: mapP's Freeview map terrainP's terrain plot wavesP's frequency data P's Freeview Detailed Coverage
Peter Henderson: How can you diplex Newcastle and CC as they are both C/D?
CC uses 52 and Newcastle uses 50, 55 and 59.
link to this comment |
Friday, 30 November 2012
P
Peter Henderson12:04 AM
Newtownabbey
Well, whatever it is they're using as an alternaitive in Castlewellan Dave.
There definitely doesn't appear to be a problem either with Newcastle or CC in the village, so they must be using something to combine the two. Certainly, there's no point in worrying about Saorsat if you can receive Saorview without any problems.
Unless Niall knows of someone getting Divis in the area there's probably no point in putting up large aerials for Divis. This can work out quite expensive in the long run, believe me (I know this from experience). Freesat would would be the better option, in my opinion. OK, so there are 4 or 5 channels missing on Freesat that aren't on Freeview but, conversely, there is so much more on Feesat that's not on Freeview, so it's really horses for courses.
Castlewellan does seem to be a black spot for Divis, even with the power increase at DSO, for some reason.
link to this comment |
Peter's: mapP's Freeview map terrainP's terrain plot wavesP's frequency data P's Freeview Detailed Coverage
Saturday, 22 December 2012
K
Keith1:51 PM
hi. Im in Blackrock, Co.Louth, I got a 52 element group A aerial hoping to pick up divis. When I try tuning in tv it doesnt find any services. I am getting full or almost full signal strength but signal quailty is always at zero.
I am using a Wolsey Wfav 25 variable gain mast head amp. I have tried turning it down etc and still no joy.
Anyone any Ideas
link to this comment |
Sunday, 30 December 2012
G
g duffy10:24 PM
I live in Plumbridge, Tyrone - no rte - has anyone any information - from the maps it doesnt look good. I get my Uk channels from ch. 45
link to this comment |
Monday, 31 December 2012
g duffy: The C45 signal is from the Strabane transmitter.
RT coverage is not uniform across Northern Ireland; a few pockets can't receive it.
You are looking to see if you can receive either:
1. Saorview from one of the transmitters in the Republic (overspill), or;
2. A signal from one of the three RT transmitters in the North. These are intended to complement the coverage of the overspill.
I agree that you are going to be lucky to receive RT and, as such, will probably be best consulting with an aerial installer.
The difficulty is obviously that you're in a valley.
I had a look at the centre of Plumbridge on Streetview (photos taken well before switchover in March 2009) and quite a few houses have a UHF aerial on Strabane and a horizontally-polarised VHF aerial pointing roughly 90 degrees clockwise of Strabane. By my reckoning these are pointing to Truskmore.
Prior to switchover, Ireland used VHF for some transmitters, including Truskmore:
TELEVISION FREQUENCY CHANNELS USED IN IRELAND
I'm not a professional so I wouldn't like to say whether those who could receive the VHF might be able to receive the current UHF Saorview signal.
However, as you're in a valley what can and can't be received might vary over a short distance.
link to this comment |
Select more comments
Your comment please