Digital Switchover - UTV Region (DigitalUK)

reboot

Digifriendly wrote: »

On a related note the Saorview signal from Clermont Carn is so strong at present that even with masthead amp turned off the ROI channels are coming through loud and clear on both my TVs. Would be interesting to know how far this signal is getting in NI especially where old analogue signal did not penetrate.

Very odd situation at this local,North of Analong,almost in sight of C/C,but looking at Kilkeel with Group B/V, nothing from C/C.
Mast head amp etc,Txs available ,3Rock,Kippure,IOM and Kilkeel.
All signals fine and pics steady,but nothing on CH 52.Wrong aerial ,on wrong pol,pointing wrong way,but gets everything else but C/C?
Not a problem as pictures are much superior to Sky on HD,but just interesting.Weakest sigs detected at several locals,as predicted,are on the HD Mux.Take the amp out?,or content myself?

lawhec

Digifriendly wrote: »

I once saw an aerial for CC just south of Armoy although what the reception was like I don't know. There are quite a few aerials for CC in and around Ballymena.

Despite being close to 90km in a straight line, almost all of Ballymena has a either a clear line of sight to Clermont Carn or any local obstacles are not big enough to be a major hindrance.
Armoy village centre is 117km straight line from Clermont Carn - below the horizon from Clermont Carn but looking at the terrain there's no major obstacles like large hills or mountains in the signal path. If Moville reception isn't possible, Clermont certainly seems to be worth a shot in the area.

If you want to see what the terrain between yourself and Clermont Carn is like, try http://www.heywhatsthat.com/?view=PLS83CM3 and click on "show profile" once you have set your receiving location.

jeltz

Digifriendly wrote: »

On a related note the Saorview signal from Clermont Carn is so strong at present that even with masthead amp turned off the ROI channels are coming through loud and clear on both my TVs. Would be interesting to know how far this signal is getting in NI especially where old analogue signal did not penetrate.

160kW is very strong, Divis is strong at 100kW and they are getting it 120km away. If CC wasn't vertically polarized they wouldn't be allowed to have it that high powered.

It may be closer but it is getting into dips behind hills in Down despite vertical higher frequencies having a reputation of not propagating as well over such topography, into places where the analogue wasn't getting into or was unwatchable (but you could make out something happening in all the snow). As far as I know that is why it is so powerful, to get into the drumlins of Monaghan and Down. The drumlins of Monaghan make reception of Cairn Hill variable despite being more powerful than CC. The NIMM is meant to cover everywhere else.

lawhec

jeltz wrote: »

160kW is very strong, Divis is strong at 100kW and they are getting it 120km away. If CC wasn't vertically polarized they wouldn't be allowed to have it that high powered.

It may be closer but it is getting into dips behind hills in Down despite vertical higher frequencies having a reputation of not propagating as well over such topography, into places where the analogue wasn't getting into or was unwatchable (but you could make out something happening in all the snow). As far as I know that is why it is so powerful, to get into the drumlins of Monaghan and Down. The drumlins of Monaghan make reception of Cairn Hill variable despite being more powerful than CC. The NIMM is meant to cover everywhere else.

Both Clermont Carn and Carin Hill are rated for a maximum ERP of 160kW.

jeltz

Cairn Hill used to be 800kW analogue. I thought it was 200kW at switch over, but obviously not.

The engineers must have calculated that Clermont Carn would be as important for infill in Monaghan as before and kept the power high. It certainly works in Down and I would suppose so for Monaghan unless anyone knows otherwise.

jeltz

reboot wrote: »

Very odd situation at this local,North of Analong,almost in sight of C/C,but looking at Kilkeel with Group B/V, nothing from C/C.

High frequency vertical transmissions tend to be more prone to topo problems. Just out of sight is often too far out of sight despite the power. Thats why main transmitters are horizontal and prefer the lower frequencies unless the service area is fairly flat. Vertical low powered relays in hilly areas are usually in group A to improve the chances of reception. Clermont Carn has to be vertical if they want it to be powerful or it may cause problems with other transmitters in a wide area including GB.

That said it may be that if you align right on CC or near enough you may still get a signal, it is very powerful that close.

Peter Rhea

jeltz wrote: »

The engineers must have calculated that Clermont Carn would be as important for infill in Monaghan as before and kept the power high.

RTENL probably intend the more-power-than-is-needed-to-replicate-analogue-coverage CC to help cover areas that were previously served by VHF analogue from Monaghan & can't get decent UHF from there.

watty

It's to cover Bangor (N.I., not Wales)

Peter Rhea

reboot wrote: »

Very odd situation at this local,North of Analong,almost in sight of C/C,but looking at Kilkeel with Group B/V, nothing from C/C.

Clermont is restricted in that direction: the ERP on that bearing should only be a fraction of full power.

jeltz

The same power restriction exists in part of the ards penninsula, they are further away but could still get a weak but watchable analogue signal in many places even though the maps had a big blank area of no reception. Saorview is much better there than analogue.

So he may still have a chance if he thinks it is peeking through. The only way to know is to try. Interesting to find out, not essential as he gets 3 Rock and Kippure anyway.

jeltz

Whatever the engineers intentions they have certainly made a lot of people very happy!

Mr. Rabbit

Clermont Cairn must have one of the best coverage areas in the British Isles from an analogue radio point of view.

It's receivable as far north as Portrush, believe it or not. On a bus tour down south a couple of years ago, I was able to receive it well south of Dublin. I don't think any radio transmitter on the mainland has coverage anything like this.

With an ERP of 160 kw, digital TV must be something similar. It's certainly the strongest transmitter at this location, Divis included.

jeltz

Crystal Palace tv could be received on the Belgian and Dutch coasts. If Clermont Carn was not restriced in their direction, Saorview would be easily received in coastal parts of the Blackpool, Southport and Liverpool areas.

CC radio extends a good distance west but I am not sure how much because Truskmore takes over on FM as it gets hilly in that region and chops up the CC signal.

lawhec

Mr. Rabbit wrote: »

Clermont Cairn must have one of the best coverage areas in the British Isles from an analogue radio point of view.

It's receivable as far north as Portrush, believe it or not. On a bus tour down south a couple of years ago, I was able to receive it well south of Dublin. I don't think any radio transmitter on the mainland has coverage anything like this.

FM radio from Clermont Carn does get out a fair distance, especially as 87.8 and 105.5 are fairly clear frequencies across most of Ireland, north & south. However in terms of sheer coverage area, it doesn't compete with Mount Leinster or Holme Moss in England. Kippure would also be close to both of them - it can often be received on a good radio in certain parts of Tyrone and I believe that in the pre-RDS days it was popular for many long-distance commuters and lorry drivers as you could go from Dublin to Galway without retuning. Truskmore also gets out pretty good too, I remember back in the late 90's listening to Today FM on 100.0MHz with a portable radio in a holiday home in Portstewart (this was before they eventually started on 100.1MHz from Moville).

marno21

lawhec wrote: »

FM radio from Clermont Carn does get out a fair distance, especially as 87.8 and 105.5 are fairly clear frequencies across most of Ireland, north & south. However in terms of sheer coverage area, it doesn't compete with Mount Leinster or Holme Moss in England. Kippure would also be close to both of them - it can often be received on a good radio in certain parts of Tyrone and I believe that in the pre-RDS days it was popular for many long-distance commuters and lorry drivers as you could go from Dublin to Galway without retuning. Truskmore also gets out pretty good too, I remember back in the late 90's listening to Today FM on 100.0MHz with a portable radio in a holiday home in Portstewart (this was before they eventually started on 100.1MHz from Moville).

I've been able to get steady radio from Clermont Carn in Tullylease, Co. Cork at a distance of 280km. I havent been there in a while, but the last time I was there 87.8 and 105.5 had RDS. I'll check 87.8 next time I'm there but 105.5 will likely be blocked by Christmas FM from Woodcock Hill.

Mount Leinster is receivable on the FM radio on my phone here, around 177km away from the transmitter. This includes Beat 102 103 on 102.0, although that's not great because of Today FM on 101.8. (22km from Mullaghanish)

lawhec

jeltz wrote: »

The same power restriction exists in part of the ards penninsula, they are further away but could still get a weak but watchable analogue signal in many places even though the maps had a big blank area of no reception. Saorview is much better there than analogue.

So he may still have a chance if he thinks it is peeking through. The only way to know is to try. Interesting to find out, not essential as he gets 3 Rock and Kippure anyway.

The bearing from Clermont to Annalong is approx 083 degrees, which collaborates with an ERP restriction of approx 17db down (effective ~3kW power radiated in this direction). OTOH Portaferry has a rough bearing of about 056 degrees, with about 5db down (~50kW).

Richard

jeltz wrote: »

Crystal Palace tv could be received on the Belgian and Dutch coasts. If Clermont Carn was not restriced in their direction, Saorview would be easily received in coastal parts of the Blackpool, Southport and Liverpool areas.

I'm a bit skeptical about that. No FM from CC here in Liverpool. Or is FM radio nulled also?

SRB

lawhec wrote: »

The bearing from Clermont to Annalong is approx 083 degrees, which collaborates with an ERP restriction of approx 17db down (effective ~3kW power radiated in this direction). OTOH Portaferry has a rough bearing of about 056 degrees, with about 5db down (~50kW).

That's interesting - I've a friend who is way higher than where I am in Portaferry Town, he's out on a hilltop in Ballygalget and while he had analogue CC, he can't get a decent DTT signal at all. Keeps breaking up, has a 60% strength reading, but only 4% quality. Mine is 50% and 15%.

jeltz

SRB wrote: »

That's interesting - I've a friend who is way higher than where I am in Portaferry Town, he's out on a hilltop in Ballygalget and while he had analogue CC, he can't get a decent DTT signal at all. Keeps breaking up, has a 60% strength reading, but only 4% quality. Mine is 50% and 15%.

Strange to get decent strength and poor quality.

On a hilltop as well!

I wonder if that is an older installation with an 18 element contract aerial and an unshielded amp. If the cable goes through a wall plate I have found that is more than enough to put it over the edge even when it is apparently strong. I wouldn't use wall plates these days, I drill holes in thin blank face plates. Perhaps the amp has started corroding or the aerial connection has started corroding. Perhaps damp has managed to get into the cable. Maybe there are hidden joins in the cable somewhere.

jeltz

Beware that some blank face plates are unbelievably strong. I was doing some for old people for the DSO and found the cheap thin ones best, you could drill through easily. They don't support any weight just close off the ugly hole so the thickness doesn't matter. The thick ones blunt your bit so it ends up being an expensive pain in the long run.

jeltz

Richard wrote: »

I'm a bit skeptical about that. No FM from CC here in Liverpool. Or is FM radio nulled also?

I don't know what array they use to transmit FM but I suspect that it is directed over the land and not in the sea direction. I would imagine there could be interference issues in GB if there was high power in that direction. So yes I think there will be some form of restriction.

As far as I know Kippure and Mount Leinster radio are more often received in north west England and Wales. Their height and location and the need to serve part of the seaboard means any restrictions would not be as severe.

I have used a big home made Band II aerial over 800cm long in an attic with a fairly noisy broadband VHF amp to receive FM over 200+ miles so if there is any signal to the Liverpool area, that sort of thing should pick it up.

SRB

jeltz wrote: »

Strange to get decent strength and poor quality.

On a hilltop as well!

I wonder if that is an older installation with an 18 element contract aerial and an unshielded amp. If the cable goes through a wall plate I have found that is more than enough to put it over the edge even when it is apparently strong. I wouldn't use wall plates these days, I drill holes in thin blank face plates. Perhaps the amp has started corroding or the aerial connection has started corroding. Perhaps damp has managed to get into the cable. Maybe there are hidden joins in the cable somewhere.

No, install is just over 2 years old, it's CT100 cable throughout, no faceplates and grouped Triax aerial and screened amp. It is diplexed for Divis, might ask him to try pulling the low channel leg in case it's pulling something in that's causing a problem. Given he had decent enough analogue from CC and mine was unwatchable it is a bit strange.

stam

Hi im getting dtt from brougher mt all fine just a question is there any hope they will add more power to CH 21 /24 / 27 muxs they seem to be on 2.000 Watts where CH 22 /25 / 28 the other ones seems to be 20.000 Watts

excollier

Freeview is now at full power, no increases planned, or required

Peter Rhea

stam wrote: »

Hi im getting dtt from brougher mt all fine just a question is there any hope they will add more power to CH 21 /24 / 27 muxs they seem to be on 2.000 Watts where CH 22 /25 / 28 the other ones seems to be 20.000 Watts

The commercial muxes from Brougher are co-channel with the PSB muxes from Divis & PSBs take priority where interference issues are concerned.

Mr Cumulonimbus

tvman2 wrote: »

Ch23 fine this morning I assume with the change in weather, no fluctuations in signal strength/quality.

Been away for a week. Checked mine now as well. Signal quality around 30% again. C/N: 18 to 19. Picture steady. Yes, I'd say lift conditions around 24 October affected signal.

tadgh

Mr Cumulonimbus wrote: »

Been away for a week. Checked mine now as well. Signal quality around 30% again. C/N: 18 to 19. Picture steady. Yes, I'd say lift conditions around 24 October affected signal.

Ch. 23 keeps alternating between 0% and 33% quality for me. (3 miles south of Dundalk).
No channels found on manual scan on Ch. 23
Ch. 21 showing approx. 85% quality

jeltz

I am starting to wonder if a vertical stack might be the cure for some peoples problem.

It isn't really fair on the average person though as there are no easy cures at all.

lolie

Not sure where to put this so went here.
My sister bout a new LG freeview hd telly at the weekend for her flat in oldcastle meath.
So on sunday evenin i wired it up and tuned in all stations.
All the saorview stations and bbc's perfect but some like Dave, Viva, Quest Sky news were suffering from some breakup.
But channels 21, 22, 24, 25, 27, 28 , 30 and 47 all showing 90-100% signal strength and 100% quality.
I'm wondering whats causing the break up if there's 100% quality, interference? to strong of signal?

The Cush

lolie wrote: »

All the saorview stations and bbc's perfect but some like Dave, Viva, Quest Sky news were suffering from some breakup.
But channels 21, 22, 24, 25, 27, 28 , 30 and 47 all showing 90-100% signal strength and 100% quality.
I'm wondering whats causing the break up if there's 100% quality, interference? to strong of signal?

Channels like Dave, Viva, Quest, Sky News are on the lower power commercial multiplexes, signal strength is probably closer to the 90% end of the scale and may be prone to occasional drop in signal quality and picture breakup.

47 - Saorview, Cairn Hill (160kW)
22, 25, 28 - Freeview PSB muxes, Brougher Mt (20kW)
21, 24, 27 - Freeview COM muxes, Brougher Mt (2kW)
30 - Freeview NImux, Brougher Mt (1kW)