Digital Switchover - UTV Region (DigitalUK)

tvman2

CRM Ireland wrote: »

Id really love to have the full freeview. At the moment my antenna is vertical and pointing directly at the Kilkeel transmitter. I can see it from my window.

Here is a very short video Ive just taken standing at the front door panning from West to East looking from Castlecoe Hill in Clogherhead towards Northern Ireland. My antenna is pointing in the direction of exactly when the video ends.

Looking at the map location of the Divis transmitter, I should be pointing a bit more to the West. Would I have to turn my antenna so thats its laying horizontal? Does it have to be line of sight? Or does the signal bend over mountains etc? I dont think bend would be the technical term, but Im sure you know what Im asking!

http://www.youtube.com/watch?v=qlr2uOHLjzY&feature=youtu.be

This might be of some interest. The map shows the positions of both tx sites in relation to a position 500m west of the Castlecoe Hill Road Callystown T junction. Looks like the path from Divis is just avoiding most of the highest points in Cooleys and The Mournes.

mrdtv2010

tvman2 wrote: »

This might be of some interest. The map shows the positions of both tx sites in relation to a position 500m west of the Castlecoe Hill Road Callystown T junction. Looks like the path from Divis is just avoiding most of the highest points in Cooleys and The Mournes.

Clogherhead should work. I suddenly remember that I saw BBC2 in a house in Clogherhead in the period when BBC1 and UTV were VHF 405. This would have been before 1970 when UHF BBC1 and UTV started from Divis., so it had to be Divis as Kilkeel would have been converted to UHF working much later. The BBC2 picture was a bit noisy but perfectly watchable (CCIR Grade 3.0). The OP should look at the surrounding aerials. Obviously after Kilkeel opened all the installs would have been for Kilkeel as until 1997-1998 the channel choice from Divis was identical.

kazoo106

Regarding Divis - Everywhere south of the Cooleys is blocked, this however does not mean that reception will not be possible.
I attach some images below


Divis To Clogherhead church - Note that part of the freznel zone is under the water of Dundalk bay.


Divis to Dundalk - Completely blocked by the cooleys, however satifactory results still being obtained.


Divis to Dublin Airport - As can be seen here, Divis is over the horizon, plus the Mornes are in the way 60km out.

550MHz does not work on a pure Line of sight basis however - The next two images are based on total coverage from Divis and the same focused in on Co. Louth. - Anywhere with even light blue will work

mrdtv2010

kazoo106 wrote: »

Regarding Divis - Everywhere south of the Cooleys is blocked, this however does not mean that reception will not be possible.
I attach some images below


Divis To Clogherhead church - Note that part of the freznel zone is under the water of Dundalk bay.


Divis to Dundalk - Completely blocked by the cooleys, however satifactory results still being obtained.


Divis to Dublin Airport - As can be seen here, Divis is over the horizon, plus the Mornes are in the way 60km out.

550MHz does not work on a pure Line of sight basis however - The next two images are based on total coverage from Divis and the same focused in on Co. Louth. - Anywhere with even light blue will work

Nice software: what are you using? NB according to the mb21 web site Divis B from which BBCA is radiated has a site height of 365.8m and structure height of 156.8m , where did you get your parameters ( The differences in totals are small.) As you correctly say Group A frequencies do diffract better which means it may indeed work in Clogherhead and the results around Dundalk are also significant, but this may be due to OFDM systems able to use reflected signals very efficiently. The blue patches are very interesting indeed.

kazoo106

Here is the same parameters for Kilkeel @ 400W

mrdtv2010

kazoo106 wrote: »

Here is the same parameters for Kilkeel @ 400W

Those two maps you have posted tie in nicely with the emerging reception reports on the ground for Divis and Kilkeel. This should make installers and DIY'ers well informed.

reslfj

kazoo106 wrote: »

Here is the same parameters for Kilkeel @ 400W
<Picture removed>

Very nice graphs and maps.

What values are each colour ?

I think a map with the Camlough transmitter could be very interesting.

And a map where the COM muxes from Brougher is say 20 dB below the Divis PSB muxes (i.e. a map where the same colours represent a (noise) signal 20 dB below the colours on the Divis map)

Lars

Peter Rhea

Might be a help if people didn't quote the maps in their replies too.

lucernarian

Camlough is by no means omnidirectional so someone will need the relevant data to produce an accurate plot. That was witheld from ukfree.tv's FOI request because it was information materially relevant to ongoing international negotiations between HM Govt. and other countries and would have apparently hindered Ofcom et al.'s bargaining position.

kazoo106

kazoo106

Peter Rhea

Aren't the Divis transmit aerials more like 150 MAGL? And the site itself closer to 360 MASL?

EDIT: Didn't notice this was already asked.

mrdtv2010

Peter Rhea wrote: »

Aren't the Divis transmit aerials more like 150 MAGL? And the site itself closer to 360 MASL?

EDIT: Didn't notice this was already asked.

http://tx.mb21.co.uk/gallery/gallerypage.php?txid=533

kazoo106

The location I have used for Divis is 54.611143,-6.016647
Ther MB21 location is Quite a bit down on the mountain - take a look on Google Earth or maps, so there is a possibility I'm using the wrong site

Peter Rhea

The tv masts are down the mountain to the southeast.

kazoo106

will prob make very little difference - cant be bothered running that 16bit program to see !!! takes about 15 minutes to run the prediction. Plus I have underestimated the mast height

mrdtv2010

kazoo106 wrote: »

The location I have used for Divis is 54.611143,-6.016647
Ther MB21 location is Quite a bit down on the mountain - take a look on Google Earth or maps, so there is a possibility I'm using the wrong site

After a bit of searching on Divis E27:

551m, page 36:

http://licensing.ofcom.org.uk/binaries/tv/sup_dso/v8.pdf

Also gives all the parameters for the other stations and frequencies. I also understand that the withheld radiation patterns may be released post-DSO as the bilateral negotiations are effectively concluded now.

mrdtv2010

kazoo106 wrote: »

will prob make very little difference - cant be bothered running that 16bit program to see !!! takes about 15 minutes to run the prediction. Plus I have underestimated the mast height

Yes, your aggregate aerial height is only 10m out from the official Ofcom licence. So it will make little difference. Thanks for posting all those runs: highly informative and ties in with the anecdotal evidence on the ground.

davehey79

im absolutely useless at these things but i have saorview from cairn hill perfectly what im wondering is can i pick up the Freeview HD channels. Im in Longford Town 48m ASL

sesswhat

davehey79 wrote: »

im absolutely useless at these things but i have saorview from cairn hill perfectly what im wondering is can i pick up the Freeview HD channels. Im in Longford Town 48m ASL

It would be a good starting point if you have ever received any of the UK channels through an aerial before?

Richard

kazoo106 wrote: »

The location I have used for Divis is 54.611143,-6.016647
Ther MB21 location is Quite a bit down on the mountain - take a look on Google Earth or maps, so there is a possibility I'm using the wrong site

davehey79 wrote: »

im absolutely useless at these things but i have saorview from cairn hill perfectly what im wondering is can i pick up the Freeview HD channels. Im in Longford Town 48m ASL

Can you get the BBC digital channels now? If not, Freeview (and Freeview hd with the appropriate receiver) should be available in Longford with the right aerial. Best to ask a local aerial installer to be sure. Freesat may be easier.

reslfj

kazoo106 wrote: »

The location I have used for Divis is 54.611143,-6.016647
Ther MB21 location is Quite a bit down on the mountain - take a look on Google Earth or maps, so there is a possibility I'm using the wrong site

Google earth has these values for Lat, Lon (decimal)

Black Mountain 54.587063°    -6.021882°

Divis          54.607500°    -6.009444°

I think your position is the two smaller mast on the hilltop behind the new Divis mast (in this MB21 picture it's under construction)
http://admin.mb21.co.uk/tx/userimages/3005orig.jpg
They are also show here:
http://www.panoramio.com/photo_explorer#user=5683581&with_photo_id=49765654&order=date_desc

With a ~150 m mast I think the 500-510 masl is all all that matters (some 30-40 m higher than shown on your graphs)


Lars

lawhec

Plenty of homes in Longford town have large (but not excessively high above ground or roof) aerials pointing towards Brougher Mountain. If analogue reception previously was OK, Freeview reception (at least for the PSB multiplexes) shouldn't be too much of a problem.

JJDoherty

kazoo106 wrote: »

The location I have used for Divis is 54.611143,-6.016647
Ther MB21 location is Quite a bit down on the mountain - take a look on Google Earth or maps, so there is a possibility I'm using the wrong site

Would there be any chance of creating a coverage map like the others for the Limavady transmitter, having already kindly provided one for Divis and Brougher, to complete the set? I'd definitely find it very useful.

lawhec

Just an anecdotal story from last weekend. The previous weekend I was at my grandparents whom up until that time had the full Freeview service albeit they are right on the fringes of reception from Brougher Mountain and Muxs 2 & A are susceptible to breaking up. Anyway I left the TV to auto-update and if that didn't work, wrote down a set of instructions on how to perform a manual tune and to phone me if necessary. Upon visiting last Saturday, everything seem to work OK with the exception that BBC News for some strange reason was absent - the rest of the BBC Channels were there. Anyway a manual tune solved the problem. On the TV's arbitrary meter, all the pre-DSO multiplexes were 1/7 while the new BBC A multiplex was 3/7, so a definite improvement. Also quite crucially there was no sign of a usable signal of the BBC A mux from Divis on E27 - Digital UK's postcode checker for their home suggests that they could lose the SDN and Arqiva multiplexes post-DSO because of co-channel interference, so at least that looks a little less likely. They also have an aerial aimed at Clermont Carn for RTÉ but this hasn't been working for several months - an installer from the switch over help scheme is coming out to them but because of backlogs it'll be early December before they can come out!

Later on there was a trip up to my uncle's farm (which I occasionally reference here in some posts as being the back arse of nowhere) which is nestled right in among the Sperrins with several tall mountains surrounding them - their primary method of TV reception is via Sky at present in the living room with a FTA receiver in the children's play room, when they moved in a few years ago they had roof aerials installed, a UHF Group A high-gain from Brougher Mountain and a VHF 5-element for Truskmore. On analogue RTÉ1 and RTÉ2 from Truskmore are surprisingly good but the analogue picture from Brougher was quite grainy and Freeview reception pre-DSO not possible except on some days and even then pictures often broke up. He mentioned about BBC2 closing on analogue and I asked him did he check to see if he could get the new BBC multiplex - said he hadn't tried so we went to the main TV first. I was reasonably confident that he'd get a half-decent signal now but he was more sceptical, so he was pleasantly surprised when the single signal meter on E28 was about two-thirds of the way up. Interestingly there was a weak but usable signal on E26 which was actually a bit of a shame because there's nothing there FTA that isn't on the BBC A mux! Not bad though considering the DUK postcode checker predicts no DTT reception at all. We went around two more televisions which had built in DTT tuners and again, the BBC A and Mux B tuned in on both of them. Notably on one of the TVs during an automatic scan, the scan did pause for a while on each of the other four muxs currently from Brougher but the signal wasn't strong enough to store. Also it paused in a similar fashion on E27 but didn't get a usable signal either - I'm not sure wherever that means they'll have enough elbow room when reception of the SDN and Arqiva multiplexes from Brougher post-DSO will already be a fair bit weaker than the PSB's, I suppose I'll find out in just over a week's time. Mentioned to him about the NIMM as well which I said he should be able to receive (with a Freeview HD receiver) too though he was a bit disappointed about no TV3 on it, said that the only way was Saorview. He asked about the RTÉ aerial he currently had and I said that a UHF aerial would need to replace that to be able to receive it. After the 24th, the first chance I can get up there we're going to try a little further up a lane at the mountain they're on using (roughly level to their roof line) a Group C/D aerial to see if either Truskmore, Clermont Carn or Carin Hill can give stable results (I know Carin Hill is not Group C/D, but E47 should still be picked up OK on such an aerial to test with). If it results that all muxs from Brougher come in fine without interference and that Saorview can also be received OK, he'll ditch Sky, as his only main motivation right now to keep it is Champions League soccer.

More to come. Maybe.

Mr. Rabbit

Interestingly Lawhec, Digital UK has downgraded my reception of the COM multiplexes from good to variable post DSO. Even Channel 34 goes from good to variable, dispite the power increase. I don't believe them, as the high power tests on 23 a couple of weeks ago were excellent.

As an aside, a leaflet from Sky in the Belfast Telegrapgh included TV3 along with RTE One, RTE Two, and TG4 in their basic NI package ?????????

Obviously an error, but you never know

I was also pleasantly surprised at how good Carnmoney Hill was off an RTE aerial, despite the fact that analogue receoption is very poor. It's given me a bit of hope that I'll definitely get Saorview from Clermont Cairn once the power is turned up and null to the north is removed next Wednesday. Analogue reception from Clermont Cairn is every bit as good as Divis, but no Saorview at this moment in time.

Roll on next week !

It'll be interesting to see how the new power levels and Carnmoney Hill fare under lift conditions when I get wiped by Caldbeck at this location.

Peter Rhea

Mr. Rabbit wrote: »

Digital UK has downgraded my reception of the COM multiplexes from good to variable post DSO. Even Channel 34 goes from good to variable, dispite the power increase.

You mean mux D that becomes Arqiva B & moves from ch. 34 to ch. 29 on the 24th, were it will be co-channel with Caldbeck's Arq B mux, which only goes to full power on the same day?

Mr. Rabbit

Peter Rhea wrote: »

You mean mux D that becomes Arqiva B & moves from ch. 34 to ch. 29 on the 24th, were it will be co-channel with Caldbeck's Arq B mux, which only goes to full power on the same day?

Yep, that and the other COM multiplexes are downgraded.

Even the high power Caldbeck multiplexes don't come in here except under lift conditions.

Personally, I can't see it being too much of a problem now that Arqiva B is at 50 kw and Calbeck is off the back of a small wideband aerial pointing at Divis.

Still, we'll see what it's like under lift conditions, and at least I've got Carnmoney Hill to fall back on now !

mrdtv2010

Mr. Rabbit wrote: »

Yep, that and the other COM multiplexes are downgraded.

Even the high power Caldbeck multiplexes don't come in here except under lift conditions.

Personally, I can't see it being too much of a problem now that Arqiva B is at 50 kw and Calbeck is off the back of a small wideband aerial pointing at Divis.

Still, we'll see what it's like under lift conditions, and at least I've got Carnmoney Hill to fall back on now !

Divis is going to 50kW for COMs as are the co-channel Caldbeck COMS on the morning of the 24th. However, Caldbeck is a long way from your location and probably has beam tilting implemented. Cambret Hill is used to complete the PSB coverage in Dumfries & Galloway as Caldbeck has such a long sea path from the Lake District along the Solway Firth.

In fact:

http://www.digitaluk.co.uk/postcodechecker/main/trade/DG+8+8PY/33/0/NA

this shows that beam tilting appears to be implemented by Caldbeck and Divis in both directions: makes sense.

Ronnie Raygun

mrdtv2010 wrote: »

... this shows that beam tilting appears to be implemented by Caldbeck and Divis in both directions: makes sense.

Why do you keep going on about beam tilting? Doesn't every transmission site (the high power ones anyway) implement it to some extent, for reasons of efficiency if nothing else?