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.
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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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Sunday, 21 October 2012
Briantist: Going back to what devices will receive the NIMM, what about Full HD TVs that don't have a DVB-T2 tuner in?
Will these be able to decode the MPEG4 using DVB-T?
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Briantist: Sorry, I confused NIMM and Saorview!
The question should be will Full HD TVs that don't have DVB-T2 built in be able to receive Saorview? I guess that they might be able to do as they will have MPEG4 decoders in. Is this correct?
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Tuesday, 23 October 2012
At switchover the Divis transmitter will be off air from midnight until 6am on 24th October 2012 - see UK Digital switchover ends - Northern Ireland completes on 24th October 2012 | ukfree.tv - 10 years of independent, free digital TV advice for full details.
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At switchover the Divis transmitter will be off air from midnight until 6am on 24th October 2012 - see UK Digital switchover ends - Northern Ireland completes on 24th October 2012 | ukfree.tv - 10 years of independent, free digital TV advice for full details...
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Neil Robertson11:33 AM
Not really a question or comment but a little bit of news of what can be one with
a little bit of ingenuity and luck.
I live in Largs on the west coast of Scotland and we have been able to get a reasonable
(but not perfect) analogue picture from Divis provided we pointed our group A aerials in the right direction (I have a sea-path all the way although I am only about 30ft above sea-level). When we switched over to digital we were only provided with the usual 3 x multiplexes from our local relay (Rothesay) which gave us more channels than the 4 analogue
ones we had. There is no possibility of receiving the other multiplexes from a main station
due to topography.
Since my new Smart TV has USB record and will only record from terrestrial digital
and not from SCART/HDMI I wondered if I could get some extra channels from Divis
post-DSO which I could record.
I built (Yes-built) myself another Group A aerial and pointed it at Divis. This last week
has been really handy as I have been able receive both analogue and digital signals from
Divis. The analogue signals make it easy to align the aerial.
Today (1 day before switch-over) with my aerial in the roof-space I can get a noisy analogue signal from Divis (at 500KW) which would be almost watchable while the BBCA Multiplex (at 100Kw) is fine with no dropouts. Interesting that there is enough resilience
in the data stream to cope with this!
Tomorrow (post-DSO) I will find out if my plan to get more channels via the SDN ARQA
and ARQB multiplexes from Divis will work -these will be at 50Kw so they are 3db down
on the BBCA Multiplex
if my plans work out I will have digital TV on
Ch 21 Divis D3+D4
Ch 22 Rothesay BBC
Ch 23 Divis SDN
CH 24 Divis BBC B
Ch 25 Rothesay D3+D$
Ch 26 Divis ARQA
Ch 27 Divis BBC A
Ch 28 Rothesay BBC A
CH 29 Divis ARQB
This is something the frequency planners never foresaw - will the tuner cope?
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Neil Robertson: The frequency planners use the frequencies that are available. There are some areas that can receive the "right" region from the local PSB-only relay and the COM channels from a transmitter of another region, but who cannot combine the two due to the channels used not allowing so.
Largs has its own relay on top of the Academy which is Group B, so can you receive from it you could diplex it with Divis. Or is there another transmitter that you could pick-up from?
The other alternative is to have two tuners. Make the "main" one (e.g. that in your TV) tuned to Divis for PSB and COM channels. Then switch to the secondary (set-top box) for regional programming.
I don't know how much of an issue receiving channels from different regions will be with regards the EPG data and recording. I know that a few regions broadcast EPG data for neighbouring regions for this reason, but this isn't something that reciprocates between Black Hill and Divis regions (that I know of). If it does prove to be an issue, then you may have to resort to using Divis except where there is regional programming only available from your local transmitter.
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Wednesday, 24 October 2012
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william1:55 PM
what is needed to get RTE on freeview in Ballyclare area?
Have re-tuned and have 120 channels but RTE isn't amongst them
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william: Reception of RT from Black Mountain (which is adjacent to Divis) requires a Freeview HD receiver. This is because the signal uses the DVB-T2 specification which is that used by Freeview HD broadcasts, although these channels are in standard definition only.
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PaulN2:54 PM
Reporting MUCH improved signal quality from Divis in islandmagee area from early this morning. Avoidance of CH33 nicely prevents horrors of "lift effect" which previously caused severe interference from the Cumbria mast.
Also happy to report that my T2 equipped Panasonic is nicely picking up NIMM albeit with less quality reported by the UI but no visible defects noted yet.
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sweetymillar2:57 PM
I can't get utv channels. The menu button does not bring up the right icons or instructions. I have a digital tv with built in freeview. Can anyone help
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