Full Freeview on the Divis (Northern Ireland) transmitter
 | 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.
This transmitter has no current reported problems
The BBC and Digital UK report there are no faults or engineering work on the Divis (Northern Ireland) transmitter._______
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
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Tuesday, 16 October 2012
Dave Lindsay: In theory, it is possible. However, Ofcom has a policy of NOT allowing MPEG4 on DVB-T, because there is a clear consume update path: Freeview HD.
You may recall that the "Sky Picnic" idea was rejected for this reason.
The long-term plan is to migrate all services to DVB-T2/MPEG4, even if they are not HD. This is in the "2020-25" planning area.
If 4G mobile services are going to expand, it is possible (not confirmed) that the three commercial multiplex will move to three single-frequency network using DVB-T2/MPEG4. Or even DVB-T2 with HEVC http://en.wikipedia.org/w…HEVC
I have created a graphic to help understand which boxes work on what...
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... Saorview is DVB-T not DVB-T2.
DVB-T2 not only offers better rates, but is more "robust" (less prone to interference) and works better in single-frequency networks.
See Freeview modes - a simplified explanation | ukfree.tv - 10 years of independent, free digital TV advice for full details
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Briantist: Thanks.
So Freeview HD (PSB3 mux) uses DVB-T2 with 256QAM. Is the reason that the NIMM is much more robust (and can therefore carry further with much less ERP) because it uses 16QAM?
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Wednesday, 17 October 2012
Dave Lindsay: Yes, that is correct.
DVB-T2 is also more robust than DVB-T at the same outputs as it has a more "modern" error correction system and it also uses advances such as the "rotated constellation".
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M
mrdtv12:38 PM
Briantist: The mode used by NIMM is in fact QPSK, 32k, 1/32, one of the most robust modes. See DUK's postcode checker.
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Saturday, 20 October 2012
E
elaine8:39 PM
very bad digital signal on c 5 and and utv is there a problem in the lisburn area bbc fine bt28
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K
KMJ,Derby10:05 PM
elaine: From Wednesday (24th October 2012) UTV, C5 etc will be carried on Mux D3+4 at 100kW. This is an increase in power from the present 2.3kW on Mux2. You should have much improved reception from then.
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K
KDM10:06 PM
I'm in N'ards, just on the fringe of the green area for Divis. After retuning on the 10th, I lost about 30 channels and UTV is now pretty unwatchable, interspersed with chirps inteh audio and blocky video. I had multiple cable drops from my antenna and have even removed my splitter and patched the aerial directly to the main TV.
Still not a lot of joy. Any suggestions gratefully received, please.
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K
KMJ,Derby10:29 PM
KDM: As with my post above to elaine, following DSO stage 2 on Wednesday 24th October 2012, when the Divis PSB muxes will all radiate at 100kW and the COM muxes will be at 50kW you should notice a considerable improvement in reception. At present some receivers do not perform well on the low power transmissions due to the presence of the high power Mux BBCA.
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K
KDM10:50 PM
Thanks for response. I understand the signal boost on 24th and I'm also given to believe that we have a third retune sometime in November which not everyone does. Am I reading you right that, basically, some channels have already been boosted and they're overpowering the others as far as my TV is concerned? Thanks again.
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