menuMENU    UK Free TV logo Freeview

 

 

Click to see updates

Full Freeview on the Divis (Northern Ireland) transmitter

first published this on - UK Free TV
sa_streetviewGoogle Streetviewsa_gmapsGoogle mapsa_bingBing mapsa_gearthGoogle Earthsa_gps54.607,-6.009 or 54°36'24"N 6°0'34"Wsa_postcodeBT17 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.

Are there any planned engineering works or unexpected transmitter faults on the Divis (Northern Ireland) mast?

Divis transmitter - Divis transmitter: Possible effect on TV reception week commencing 25/03/2024 Pixelation or flickering on some or all channels Digital tick


Choose from three options: ■ List by multiplex ■ List by channel number ■ List by channel name
_______

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.

MuxH/VFrequencyHeightModeWatts
PSB1
BBCA
 H max
C27 (522.0MHz)551mDTG-100,000W
Channel icons
1 BBC One (SD) Northern Ireland, 2 BBC Two Northern Ireland, 9 BBC Four, 23 BBC Three, 201 CBBC, 202 CBeebies, 231 BBC News, 232 BBC Parliament, plus 14 others

PSB2
D3+4
 H max
C21+ (474.2MHz)551mDTG-100,000W
Channel icons
3 UTV (SD) (UTV), 4 Channel 4 (SD) NI ads, 5 Channel 5, 6 ITV 2, 10 ITV3, 13 E4, 14 Film4, 15 Channel 4 +1 NI ads, 18 More4, 26 ITV4, 28 ITVBe, 30 E4 +1, 35 UTV +1 (UTV),

PSB3
BBCB
 H max
C24 (498.0MHz)551mDTG-100,000W
Channel icons
46 5SELECT, 101 BBC One HD Northern Ireland, 102 BBC Two HD Northern Ireland, 103 UTV HD (UTV), 104 Channel 4 HD NI ads, 105 Channel 5 HD, 106 BBC Four HD, 107 BBC Three HD, 204 CBBC HD, 205 CBeebies HD, plus 1 others

COM4
SDN
 H -3dB
C23 (490.0MHz)551mDTG-850,000W
Channel icons
20 Drama, 21 5USA, 29 ITV2 +1, 32 5STAR, 33 5Action, 38 Channel 5 +1, 41 Legend, 42 GREAT! action, 57 Dave ja vu, 58 ITVBe +1, 59 ITV3 +1, 64 Blaze, 67 TRUE CRIME, 68 TRUE CRIME XTRA, 78 TCC, 81 Blaze +1, 83 Together TV, 89 ITV4 +1, 91 WildEarth, 209 Ketchup TV, 210 Ketchup Too, 211 YAAAS!, 267 Al Jazeera English, plus 30 others

COM5
ArqA
 H -3dB
C26 (514.0MHz)528mDTG-850,000W
Channel icons
11 Sky Mix, 17 Really, 19 Dave, 31 E4 Extra, 36 Sky Arts, 40 Quest Red, 43 Food Network, 47 Film4 +1, 48 Challenge, 49 4seven, 60 Drama +1, 65 That's TV 2, 70 Quest +1, 74 Yesterday +1, 75 That's 90s, 233 Sky News, plus 11 others

COM6
ArqB
 H -3dB
C30 (546.0MHz)528mDTG-850,000W
Channel icons
12 Quest, 25 W, 27 Yesterday, 34 GREAT! movies, 39 DMAX, 44 HGTV, 52 GREAT! romance, 56 That's TV (UK), 61 GREAT! movies extra, 63 GREAT! romance mix, 71 That’s 60s, 73 HobbyMaker, 82 Talking Pictures TV, 84 PBS America, 235 Al Jazeera Eng, plus 18 others

LBT
 H -13dB
C36 (594.0MHz)528mDTG-125,000W
Channel icons
from 29th September 2014: 7 NvTv,

NIMM
 H -40dB
C48 (690.0MHz)551mDTG-10W
Channel icons
from 4th September 2019: 53 TG4, 54 RTÉ One, 55 RTÉ Two,

DTG-8 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?

regional news image
BBC Newsline 0.6m homes 2.5%
from Belfast BT2 8HQ, 1,044km northeast (51°)
to BBC Northern Ireland region - 46 masts.
regional news image
UTV Live 0.6m homes 2.5%
from Belfast BT7 1EB, 1,044km northeast (51°)
to UTV region - 46 masts.

Are there any self-help relays?

Chapel FieldsTransposerCentral Belfast61 homes

How will the Divis (Northern Ireland) transmission frequencies change over time?

1950s-80s1984-971997-981998-20122012-134 Mar 2020
VHFA K TA K TA K TK TW T
C1BBCtvwaves
C21C4wavesC4wavesC4waves+D3+4D3+4
C23SDNSDN
C24ITVwavesITVwavesITVwavesBBCBBBCB
C26ArqAArqA
C27BBC2wavesBBC2wavesBBC2wavesBBCABBCA
C29ArqB
C30LBT
C31BBC1wavesBBC1wavesBBC1waves
C33com7
C34com8
C36_local
C48NIMMNIMM
C55tv_offcom7tv_off
C56tv_offCOM8tv_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

Oct 1959-May 2006Ulster Television
May 2006-Dec 2014UTV plc
Feb 1983-Dec 1992TV-am•
Jan 1993-Sep 2010GMTV•
Sep 2010-Dec 2014ITV Daybreak•
• Breakfast ◊ Weekends ♦ Friday night and weekends † Weekdays only. Divis was not an original Channel 3 VHF 405-line mast: the historical information shown is the details of the company responsible for the transmitter when it began transmitting Channel 3.

Comments
Saturday, 14 September 2019
C
CP
12:25 PM

Thanks so much Chris.SE. What is the plan for the channels that currently reside on com7/8 when they close down? I actually like some of them!

I haven't changed anything, but am now able to receive and tune com8 on Ch 60, albeit with pretty variable signal quality, but get nothing on com7 on Ch 51.

I used an SDR dongle as a very rudimentary spectrum analyser, and I am receiving an 8MHz wide signal that is centred around 714MHz, which corresponds to Ch 51. In terms of raw received power it is actually comparable to the other muxes, but as you suggest it must be getting scrambled with interference as all of my devices read 0 signal quality and are unable to tune it. I'm not sure that there is too much I can do about that.

link to this comment
CP's 4 posts GB flag
Tuesday, 1 October 2019
C
CARL READE
sentiment_satisfiedBronze

2:27 PM

Hi can anyone confirm Claremont Carn has reduced its power on 52 and 56? As there is no response the site.

link to this comment
CARL READE's 51 posts GB flag
C
Chris.SE
sentiment_very_satisfiedPlatinum

3:22 PM

CARL READE:

Don't know if these sites are any help, Clermont Carn has supposedly changed channels to 42 & 45.
http://coverage.2rn.ie/in….php
Saorview

Information certainly seems sparse, I wonder if anyone else has any info/links etc.?

link to this comment
Chris.SE's 4,101 posts GB flag
C
CARL READE
sentiment_satisfiedBronze

5:18 PM

Chris.SE: Yea was on the site zero info. They are still at 52, 56 and 42, 45 but people telling me they have lost 52, 56. Strange as they didn't move after the retune.

link to this comment
CARL READE's 51 posts GB flag
Wednesday, 2 October 2019
C
Chris.SE
sentiment_very_satisfiedPlatinum

3:58 PM

CARL READE:

It's possible they may be simulcasting for a while (possibly on lower power?) so that people with unsuitable aerials have time to get them changed. They've simulcasted PSB1/BBCA on a few transmitters in GB when main mux channels have moved from group C/D aerial to group A.

link to this comment
Chris.SE's 4,101 posts GB flag
Sunday, 6 October 2019
D
Denis
sentiment_satisfiedBronze

3:33 PM
Downpatrick

CP re Ch51

I am in a 2nd floor flat in Killyleagh, not line of sight from Divis. Communal small-ish log-periodic in the loft. LG TV.

Ch51 shows sig strength of 70%, a bit variable but no pic drop outs or pixellation on any of the 10 TV channels (including BBC News HD and Smithsonian.
Ch60 is weaker at 50% but the picture is OK.
Ch33 is not shown on the main list, but has good signal strength. Carries only NvTv and a few Sony channels.

The Black Mountain RTE channels are listed at 2kW eirp, but it must have been upped a lot as I am now getting 100% signal strength, as with the PSB transmissions. Perhaps they have moved it to Divis?

link to this comment
Denis's 24 posts GB flag
Denis's: mapD's Freeview map terrainD's terrain plot wavesD's frequency data D's Freeview Detailed Coverage
Thursday, 10 October 2019
C
CP
1:52 PM

Thanks for the detailed info Denis. I'm a couple of miles and line of sight from Divis, so I couldn't understand what was going on. In case it helps anyone else I have now solved my tuning problems. It turns out the problem was...my flyleads!

I have 3 flyleads in series - one from the antenna wall socket to a surge suppressor, from the suppressor to my PVR, then another from the PVR to the TV. The ones to / from the PVR came with it.

My problem was that at the TV I was getting a zero signal strength reading for Ch 51 (com7) while Ch 60 (com8) was intermittently reading either 0 signal strength or occasionally 30-40%, but very poor quality.

I mentioned before that using a basic spectrum analyser showed that I appeared to be getting decent signal peaks at the appropriate frequencies, so I didn't know what was going on. However, I was only testing this at the end of the flylead from the wall socket. Doh!

A few nights ago I noticed that when I accidentally touched and moved one of the flyleads to / from PVR I suddenly briefly received better reception on Ch 60. Wondering if they were faulty I then replaced both PVR flyleads with a couple of homemade ones I put together from WF100 cable I had lying around. After replacing one, Ch60 signal strength improved to around 60%, and after replacing the second I now have a signal strength of 80+% on Ch60 and 50+% on Ch51, both with 100% signal quality!

The old flyleads were typical of those you get with devices like PVRs. They weren't that thick, but didn't appear particularly cheap. Their connectors appeared alright too. I'm not sure if they had a really poor frequency response and were overly attenuating higher frequency channels, which became noticeable when the Com7 / 8 muxes moved up to Ch 51/60, or if they just have very poor shielding and were picking up lots of interference at those frequencies. In any case, replacing them with good quality, well shielded cabling has completely solved my problem and was relatively quick and easy to do. Worth considering if anyone else has similar problems.

Thanks to all those here who contributed advice / information.

link to this comment
CP's 4 posts GB flag
C
Chris.SE
sentiment_very_satisfiedPlatinum

5:55 PM

CP:

Glad you have solved your problem. From my experience with these "pre-fabricated" fly-leads, they can often develop a break on the centre core where they enter the back of the plug. I've never discovered whether it's just a poor method of connection or the wire physically breaking, I've just binned them!

link to this comment
Chris.SE's 4,101 posts GB flag
Friday, 11 October 2019
D
Denis
sentiment_satisfiedBronze

10:42 AM
Downpatrick

CP
It happens! <lol> I've found flyleads with centre conductor just pushed into the pin, unsoldered. You can get ones with a grubscrew but I prefer to solder them - guess iI'm old fashioned! That's the Belling Lee type, you can't of course solder the F type, where the conductor is the pin.
What antenna do you use? I'm asking because a friend lives a couple of miles from Divis, and gets poor reception with a set-top aerial.
What SDR dongle do you use?

Denis GI3TAC

link to this comment
Denis's 24 posts GB flag
Denis's: mapD's Freeview map terrainD's terrain plot wavesD's frequency data D's Freeview Detailed Coverage
N
nobody
sentiment_satisfiedBronze

10:33 PM

Denis: But, assuming we aren't powering something, do we need a DC connection at all, given that the stray capacitance between the centre conductor and pin is a virtual short at these frequencies?

link to this comment
nobody's 47 posts AT flag
Select more comments

Your comment please
Please post a question, answer or commentIf you have Freeview reception problems before posting a question your must first do this Freeview reset procedure then see: Freeview reception has changed, Single frequency interference, and Freeview intermittent interference.

If you have no satellite signal, see Sky Digibox says 'No Signal' or 'Technical fault'

If you have other problems, please provide a full (not partial) postcode (or preferably enter it in box at the top right) and indicate where if aerial is on the roof, in the loft or elsewhere.

UK Free TV is here to help people. If you are rude or disrespectful all of your posts will be deleted and you will be banned.








Privacy policy: UK Free Privacy policy.