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.
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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Friday, 20 December 2013
J
jb3810:32 AM
Gavin: Considering the fact that this transmitter is only on test and is not due to go into service until next year, then the fluctuations seen in the signal level could well be as a result of the equipment being tested as engineers have a free hand in this type of situation.
However, as far as your location is concerned, I tried out quite a few test p/codes around your area and with none of them indicating that you would be able to have reliable reception from C30 transmitter even when in service, although this can be verified or not as the case may be with knowledge of your post code.
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Thanks for the reply. The coverage maps on this page show me on the edge of really good Divis reception for all muxes, with C30 signal a bit weaker than the others. Seems to tie in quite well with the signal I was getting last night since I have:
PSB muxes at 75%/100% (strength/quality)
COM4-6 at 70%/100%
COM 7 at 62%/100%.
I was just wondering if anyone else was monitoring C30 and experiencing similar fluctuations - since as you point out the tx is only on test. Should be interesting to see what the signal ends up being here due to the radiation patters depicted on this page.
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J
jb381:20 PM
Gavin: Well yes! so long as you have selected LBT and blown the picture right up, although you can obtain a more detailed prediction of reception by clicking on the undermentioned link, entering your post code and checking the "detailed view" box, this method retaining your privacy as far as exact location is concerned, although any predictions seen have always to be taken with the proverbial pinch of salt as no-one can give a 100% accurate prediction of where an UHF/RF signal will, or will not be received.
That said, the other aspect of knowing a post code is that it enables a detailed terrain check to be carried out for the purpose of determining if the signal received at a given location is via line-of-site or not, because if not then that received is via diffraction (bending) and can, dependant on other factors, be susceptible to the reflective effects of seasonal changes to the terrain, i.e: the so called "summer and winter" effect.
Digital UK - Coverage checker
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J
jb382:30 PM
Gavin: Having read over my previous reply I just noticed my grammatical error of "site" being typed in when obviously "sight" was being referred to, I shall put this down to pre Christmas fatigue!
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P
PJH11:47 PM
Gavin: I'm in the same position as you. Carmoney Hill is only a few miles away and I can see the transmitter from my bedroom window (I'm in Jordanstown).
Did a quick manual scan and found nothing on channel 30. Is it off air now ?
Com 7 coming in well although signal strength well down on even the commercial muxes, but with no break up.
Digital UK indicates no reception from channel 30 at this location, which is strange as they give me good coverage of the NI mux from Black Mountain. In practice Black Mountain is well down on the Commercial muxes from Divis, even though they're claiming variable reception for these.
I'm actually receiving Carnmoney Hill off the side of the RTE aerial.
Clermont Cairn is by far the best signal at this location. I get multiple signals from RTE !
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Saturday, 21 December 2013
G
Gavin5:43 PM
Hi PJH
C30 is still on right now. Today I'm getting mostly 40-50% strength and 70-90% quality, with some short dips to 50% quality. Still getting a few picture dropouts though.... so quality must be dropping lower than that.
Yea no probs with COM7 though :)
Thanks for the link jb38, I have looked there before, gives good reception on COM7 on C33 but no mention of C30. However the same site says I have good reception from the Black Mountain NIMux, but I can tell you I can't get a thing on C39+, probably due to the strong signal from Carnmoney Hill on C40!
As for Clermont Carn, signal is great with a Antiference XG16EW + masthead..... diplexed with the Divis aerial.
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G
Gavin5:46 PM
BTW my Divis aerial is a cheapo Maplin job from >20 years ago. I'll wait and see what the final signal is like on C30, and if there is any programme material worth watching thereon, before thinking about changing it ;-)
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Sunday, 22 December 2013
P
PJH1:27 AM
Yep, now getting the local TV multiplex on channel 30 but badly broken up. Hopefully it'll improve on launch.
Currently my Humax box is giving a 43% signal with 10% quality.
I find signals strength meters on STBs very subjective as no two models.are ever the same.
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Tuesday, 24 December 2013
P
PJH6:20 PM
Local TV mux much stronger today.
Still quite weak but no break up.
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Still dropping out occasionally for me. Tried manually tuning a liitle high because I thought it might be interference from c29, but it didn't help :/
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