Digital Switchover - UTV Region (DigitalUK)

tvman2

mrdtv2010 wrote: »

Yes, I'm afraid so. This is a known issue. Caldbeck has had a relationship with Divis in terms of channel clashes since 1998. Last week before DSO I did mention the CCI issue with Caldbeck which uses the same COM frequencies and the DUK postcode checker showed CCI effects in places such as Portavogie on the East Down coast during and after the various technical changes. An outside aerial would pull in Divis very well, possibly Cambret Hill, and Caldbeck occasionally. Caldbeck PSB England muxes can be received in East Down, PSB Scotland can't as they are lower power and there is beam tilting to avoid CCI with Divis PSB's. During lifts you will find that Caldbeck will come in so COM muxes may go down. Winter Hill is also possible. An outside aerial with a rotor offers a lot of Dxing fun but it can be a headache too!

Thanks for the reply, not a great problem as I have Freesat on the TV but it would convenient to have trouble free DTT also. I might though dig out the rotator and get back to a bit of DXing. Have a cable running from the living room to a disused 36v sat mount!

Mr Cumulonimbus

Peter Rhea wrote: »

Closer to where? Dundalk is about 145 miles from Caldbeck. It's about 95 miles from Mt.Leinster.



All the com. muxes powered up at Caldbeck, including chs. 26 & 29 & it's nowhere near the same direction as Divis from Louth/south Armagh, although we also have to account for sidelobes in the aerial's radiation pattern.

Chs 26 and 29 unaffected for me from Divis. 100% signal quality on both. It's just 23 being affected. Quality had gone down when i checked it after marclt reported Mt L was up and running Wed evening. What time did Caldbeck power up it's COM muxes?

Peter Rhea

tvman2 wrote: »

Any point in connecting an aerial outside and pointing it to Caldbeck

If you think Caldbeck is causing you problems, try experimenting with the alignment of an aerial on Divis, even moving it off Divis in an attempt to get the unwanted signal into a null in the aerial's response.

Peter Rhea

Mr Cumulonimbus wrote: »

Chs 26 and 29 unaffected for me from Divis. 100% signal quality on both. It's just 23 being affected. Quality had gone down when i checked it after marclt reported Mt L was up and running Wed evening.

Others with the problem have only mentioned ch. 23. Mt. L's transmitting aerials must be about 3,000 ft. asl, far higher than Caldbeck, with no obstacles towards the Dundalk area, apart from Earth's curvature. It wouldn't be putting out max. power to the northeast, but still considerable nonetheless.

lucernarian

Peter Rhea wrote: »

Closer to where? Dundalk is about 145 miles from Caldbeck. It's about 95 miles from Mt.Leinster.



All the com. muxes powered up at Caldbeck, including chs. 26 & 29 & it's nowhere near the same direction as Divis from Louth/south Armagh, although we also have to account for sidelobes in the aerial's radiation pattern.

Fair point. I've described before how I was able to pick up crystal-clear Mt. Leinster analogue TG4 from south Louth, albeit at a more elevated location. Even with a grid vertically polarised towards Kilkeel, watchable TG4 on Ch. 23 was picked up. When the 4 muxes on Ch. 39/42/45/49 fired up a few years back, Kilkeel reception substantially deteriorated on the same aerial.

Also, a poster here described trying to pick up the Caldbeck BBC B mux from Annalong in Co. Down but could never do so outside of lift conditions. However in Co. Louth, I've been easily able to receive watchable Mt. Leinster. Mt. Leinster broadcasts from a higher location than Caldbeck too, which is especially critical over long distances.

lucernarian

Peter Rhea wrote: »

Others with the problem have only mentioned ch. 23. Mt. L's transmitting aerials must be about 3,000 ft. asl, far higher than Caldbeck, with no obstacles towards the Dundalk area, apart from Earth's curvature. It wouldn't be putting out max. power to the northeast, but still considerable nonetheless.

I think it's more or less full power at 0 degrees bearing and must be what, -2dB at 20 degrees bearing. Mt. Leinster does have to serve parts of Kildare along with various valleys in the Wicklow Mountains.

sesswhat

talkabout wrote: »

Anyone from Balybofey, Co Donegal picking up full freeview, i appear to be getting freeview lite only from Strabane.

icom wrote: »

Picking up full freeview from Limavady
Located on high ground outside the town (Meenglass)

Similar to icom, I'm quite high up and with a view to the NorthEast (Sessiaghoneill). If you are lower down, close to the river, your chances of getting Limavady would be greatly reduced.

After years of co-channel interference from RTE2 analogue from Ballybofey on CH58, a new potential problem surfaced when the Castlederg Freeview mux started on the same channel. This is vertically polarised but is still coming in quite strong on the side of my Limavady aerial, so I had to do a bit of tweaking to pick up the Limavady COM5 mux on CH58.

The list of transmitters which can be picked up at this location now are:

Indoor aerial:

Saorview Ballybofey
Saorview Letterkenny
Freeview Strabane

Outdoor yagi:

Above +
Saorview Hollywell Hill
Saorview Truskmore
Freeview Castlederg
Freeview Limavady

Ronnie Raygun

mrdtv2010 wrote: »

... PSB Scotland can't as they are lower power and there is beam tilting to avoid CCI with Divis PSB's.

Ahh, the old beam tilt again. You don't have access to any information about the radiation patterns of UK main transmitter sites, so stop posting this kind of thing.

mrdtv2010

Ronnie Raygun wrote: »

Ahh, the old beam tilt again. You don't have access to any information about the radiation patterns of UK main transmitter sites, so stop posting this kind of thing.

Actually I do but its not for public consumption.

Ronnie Raygun

Well, for someone with access to "sensitive" information, your knowledge of the subject it relates to seems to me to be very lacking indeed.

mrdtv2010

Peter Rhea wrote: »

Closer to where? Dundalk is about 145 miles from Caldbeck. It's about 95 miles from Mt.Leinster.



All the com. muxes powered up at Caldbeck, including chs. 26 & 29 & it's nowhere near the same direction as Divis from Louth/south Armagh, although we also have to account for sidelobes in the aerial's radiation pattern.

Caldbeck's COM muxes went from 12.5kW to 50kW on 24th October as well. I think Mount Leinster would be restricted towards the NW to avoid interfering with other Saorview stations and UK DTT as well eg Divis. Caldbeck is received in lift conditions in that quadrant, and of course different channels can propagate differently. If Divis E26 and E29 go down as well then that is the primary source but its entirely possible there could be a combination of interferers.

mrdtv2010

Ronnie Raygun wrote: »

Well, for someone with access to "sensitive" information, your knowledge of the subject it relates to seems to me to be very lacking indeed.

It all depends how much can be revealed: however most of this is going to be public domain in due course as international negotiations are now wrapped up, these stations are coordinated and all are moving towards their final configurations. Apart of course from the issue of what happens to the 600Mhz band (E31-E38) whether that is going to be for more TV or allocated to MNOs.

Peter Rhea

mrdtv2010 wrote: »

If Divis E26 and E29 go down as well then that is the primary source but its entirely possible there could be a combination of interferers.

Divis Arq. A on ch.26 will probably go when Mt. Leinster mux. 2 starts.

mrdtv2010

Peter Rhea wrote: »

Divis Arq. A on ch.26 will probably go when Mt. Leinster mux. 2 starts.

When will that be, pray?

formerly scottish paddy

mrdtv2010 wrote: »

When will that be, pray?

As soon as another channel wants to go HD, and in the case of TG4, quite soon.
Also TV3 have announced a new HD studio development with Sony, so they won't be far behind.

Sam Russell

As soon as they sort out the tarriffs, I would imagine. TV3 want to go HD, otherwise their HD studio is a bit pointless. TG4 also are ready to go HD, so only RTE 1 have yet to announce plans for HD. The four HD channels would fill the two muxes together with what is already there, plus one or two SD channels.

FREETV

People suffering interference and a drop in signal quality as a result of the Caldbeck Transmitter and Mount Leinster should post over on digital spy and ukfreetv.co.uk in order for it to become widely known, then maybe a channel change may occur in he near future or something to offset the interference.

Peter Rhea

I'm sure the majority here would agree that the problems with the Divis SDN mux. are due to Mt. Leinster starting up on ch. 23.

Any Divis co-channel issues with Caldbeck will have been planned for long ago. The PSB services get better protection from interference.

Benizi

I am getting all RTE channels from Clermont but not from Blackmountain mix. Why?

Benizi

I meant Blackmountain mux.

Benizi

I am in Belfast and in clear view of Blackmountain. Confused. Is RTE being transmitted from NI yet? The RTE channels are listed when I scan, as are the programme schedules etc, but no sound or picture.

FREETV

Peter Rhea wrote: »

I'm sure the majority here would agree that the problems with the Divis SDN mux. are due to Mt. Leinster starting up on ch. 23.

Any Divis co-channel issues with Caldbeck will have been planned for long ago. The PSB services get better protection from interference.

Well RTENL made a stupid mistake in choosing a channel frequency for Mount Leinster the same as Divis, they already did the same with Preseli before and should amend the problem pronto.

MarkK

Benizi wrote: »

I am in Belfast and in clear view of Blackmountain. Confused. Is RTE being transmitted from NI yet? The RTE channels are listed when I scan, as are the programme schedules etc, but no sound or picture.

Is your TV/Box picking up BBC HD and UTV HD?
You need a Freeview HD box/TV for the NIMUX from Black Mountain.

Did you get a good TG4 from Black Mountain before switchover?

Benizi

Thanks for the response. I am getting BBCHD and UTVHD fine. I got TG4 from Clermont before switchover, but only a fuzzy TG4 from Black Mountain. I am on Saintfield Road in Belfast and high enough up to be looking straight at the transmitter towers from my window, so I didn't expect a problem picking up NIMUX. Also, as I noted, the channel names and programme schedules are there no problem, but no picture.

watty

FREETV wrote: »

Well RTENL made a stupid mistake in choosing a channel frequency for Mount Leinster the same as Divis, they already did the same with Preseli before and should amend the problem pronto.

Nonsense.

Any co-channel issues between them [Leinster & Divis] are down to poor designed aerials, poorly screened coax, a 2nd aerial picking it up or too much/poor quality mast amp.

DTT needs a MUCH better [quality] mast amp [, sometimes less gain too].

Transmitters in different places HAVE to use the same channels.

Peter Rhea

FREETV wrote: »

Well RTENL made a stupid mistake in choosing a channel frequency for Mount Leinster the same as Divis

So, did ofcom make an even stupider mistake by having the Brougher coms. co-channel with Divis PSBs? Suitable radio spectrum is a finite resource & the UHF tv band could be subject to further shrinkage in future.

Mr. Rabbit

Did you get a good TG4 from Black Mountain before switchover ?

TG4 didn't broadcast from Black Mountain before switchover, but from a very low powerd relay station at Divis (500w).

Benzi: You should have no problems with the NI Mux from Black Mountain.

It's either:

(1) A problem with your HD box/TV

(2) If you have a Sky box make sure the RF modulater isn't set to a channel close to 39 (i.e. 40 for example)

FREETV

watty wrote: »

Nonsense.

Any co-channel issues between them [Leinster & Divis] are down to poor designed aerials, poorly screened coax, a 2nd aerial picking it up or too much/poor quality mast amp.

DTT needs a MUCH better mast amp.

Transmitters in different places HAVE to use the same channels.

Okay, I don't have any reception problems luckily, I am just trying to look out for the unfortunate people in certain areas with reception problems. I made sure that I got the best equipment available.

Benizi

Got it OK now - simple aerial problem. Many thanks.

kazoo106

What is going on with the NI Mux and the aspect ratios - picked up a Bush (bush branded vestel T7650PVR) in Argos Newry last night (which I had to exchange in Dundalk because of a faulty HDMI - but thats another matter)

Firstly the NIMUX is booming into Dundalk


BUT - whats witht the odd aspect ratios - TG4 seems to be in 4:3 and RTE2 is stretched with the DOG not even appearing properly on the screen. Audio is also crap compared to the saorview MUX - has anyone mentioned this to RTE, or do they have no input to the output?





Oh - and if anyone has a firmware for this box which allows me to re-arrange channels would be much appreciated !