DTT now broadcasting from Castlebar on UHF channel 22.

Mayo Exile

Down in the folks house at Murrisk, near Westport. Did a scan just a while ago on a Sony V4500 TV and DTT is now coming from the Castlebar relay on UHF channel 22.

I think it's just come on today as I had scanned earlier this morning and nothing was there. There's a contract group A aerial in the attic and the signal is at full strength according to the TV's own signal meter. Site is elevated with the relay is visible from the house.

godskitchen

So were you getting content or is it just a test signal?

Do you know if the mast on Croaghmoyle is broadcasting anything..........

Link to said mast

http://www.mds975.co.uk/masts/castlebar.html
http://en.wikipedia.org/wiki/Castlebar_transmitter

It pretty much covers most of west/central Mayo so I would expect it to be broadcasting at some point......

John mac

I am getting all the channels. it only came on today after 12:00 (i scanned just before 12 )

Pete2k

Getting a good signal here from Castlebar on the West Roscommon/North Galway border. Kind of surprised tho as on CH21 we have Channel 4 from the Balla deflector and on CH23 we have TG4 so thought there might be too much co-channel interference to receive DTT but seemingly not.

Mayo Exile

godskitchen wrote: »

So were you getting content or is it just a test signal?

Do you know if the mast on Croaghmoyle is broadcasting anything..........

Link to said mast

http://www.mds975.co.uk/masts/castlebar.html
http://en.wikipedia.org/wiki/Castlebar_transmitter

It pretty much covers most of west/central Mayo so I would expect it to be broadcasting at some point......

Yes, all DTT content available.

Same place. Castlebar relay site also sometimes called Croaghmoyle.

@John mac. Yeah, same here. I scanned around 11am and nothing, then rescanned just after 1pm and they were there.

Smeagol

Good enough signal in north Leitrim near Manorhamilton. (S:61% Q:97% on Mvision HD200)

John mac

Smeagol wrote: »

Good enough signal in north Leitrim near Manorhamilton. (S:61% Q:97% on Mvision HD200)

Isn't that from Truskmore?

lawhec

I wonder if this is affecting anyone's BBC1 (analogue) reception in and around north Connacht?

Galway

Pete2k wrote: »

Getting a good signal here from Castlebar on the West Roscommon/North Galway border. Kind of surprised tho as on CH21 we have Channel 4 from the Balla deflector and on CH23 we have TG4 so thought there might be too much co-channel interference to receive DTT but seemingly not.

I am 10 km south of Tuam and Cbar DTT channel 22 is very strong, over 40db on an unamplified group A Triax supergain Yagi aerial held at shoulder height. I also get Ch 4 from Balla on chan 21 which is unaffected, however TG 4 analogue Cbar is badly degraded by DTT mux from Tonabrucky just outside Galway City off the N59, not very good frequency planning as it is also on ch. 23. I also wondering if BBC 1 analogue ch 22 from Brougher Mountain is being affected in east Mayo and Roscommon.

Smeagol

Isn't that from Truskmore?

Believe me I know the difference between E22 and E53. + I can see Truskmore tx from kitchen window.

Aerial is a 18 element yagi pointed towards Truskmore (S:89%Q:98), signal boosted using a 25db distribution 4-way amp. So circa 50° off for Castlebar.:eek:

I wonder if this is affecting anyone's BBC1 (analogue) reception in and around north Connacht?

I can't tell from my location because Thur mtn. is blocking the signal from both Brougher and Divis almost completely. But I'll ask around.:)

Kristopherus

Picking it up on my Sagem Picnic Box. Getting subtitles that are ahead of the speech. Is this RTENL or the box?

Mike 1972

Just happen to be staying at the parents place for a few days and picking it up.

Some observations

On an autoscan RTE2 appears before RTE1
On the RTENL (test card channel) selecting audio option "Iri" produces a test tone while selecting "Eng" gives -errrr Radio na Gaeltacht

EPG data on RTE 1 and 2 only seems to be now/next while on TG4 is a bit more comprehensive.

RTE2 and TG4 are labelled correctly wheras on analouge they STILL use the names NET2 and TnG :rolleyes:

All RTE radio services including Pulse/Chill/Gold etc (otherwise unavailable in the West of Ireland) appear to be present.

lawhec wrote: »

I wonder if this is affecting anyone's BBC1 (analogue) reception in and around north Connacht?

I daresay the choice of UHF channel is going to mean a lot of "fun" for some deflector operators along with anyone trying to pull in TV from Brougher.

Having said that direct reception of Brougher is impossible in most parts of Mayo due to various mountain ranges coupled with the riduclously low ERP used at the "Enniskillen"* transmitter. At some hilltop locations Divis actually comes in better.

Can see there being issues in parts of Co. Sligo, Roscommon etc though

* Yes I know its really in Tyrone

watty

The Deflectors are ALL supposed to close shortly.

Besides anyone rural is going to get better UK TV and more of it now free on a dish.

godskitchen

Mayo Exile wrote: »

Yes, all DTT content available.

Same place. Castlebar relay site also sometimes called Croaghmoyle.

@John mac. Yeah, same here. I scanned around 11am and nothing, then rescanned just after 1pm and they were there.

I thought, correct me if I am wrong, that the deflector site was further down the mountain on the Castlebar side next to a house........

I did not think that it was on top of Croaghmoyle, where there is one main mast which has been there for years (Since the 70's), and a smaller mast that was put up 3 years ago.

Mike 1972

The "Castlebar" RTE site and the Castlebar deflector are at different locations (albeit within the same range of hills and an aerial pointed at the latter will usually bring in the former.

The Wikipedia article which someone linked to above explains the setup fairly well.

For what its worth the Castlebar deflector still seems to use terrestrial off air feeds for some channels and Satellite (SW England region IIRC) for others. THey also carry TV3 on Ch 39 but picture quality on the latter is pretty abysmal due to (among other things) BBC2 from Westport being co-channel.

TBH (other than for TV3) there probably isint much need for a deflector service in this day and age and its all due to end come 2012 anyway

byte

A workmate of mine was talking to me today about his BBC1 from Brougher having gone poor in the past 2 days. I get a funny feeling it's because of Castlebar DTT.

He is at the highest point of Mountcharles, Donegal looking over the sea, and I'd doubt there'd be much to block Castlebar DTT.

I'll have ot call to his house someday to sort it - he really shouldn't have a masthead amp for Brougher, considering his location, as signal bangs in there.

lawhec

Mike 1972 wrote: »

Having said that direct reception of Brougher is impossible in most parts of Mayo due to various mountain ranges coupled with the riduclously low ERP used at the "Enniskillen"* transmitter. At some hilltop locations Divis actually comes in better.

Can see there being issues in parts of Co. Sligo, Roscommon etc though

Brougher isn't really underpowered unless you consider 100kW a "ridiculously low ERP", but rather that the transmissions are slightly directional to the NE with a slight null to the SW (I know that for FM radio the null is 6db under international agreement but Downtown and Q101 have slightly higher nulls to be cautious, not sure for UHF) and that it's serving an area whose terrain is quite tricky to cover. Divis OTOH has no directional restrictions and so its 500kW ERP goes towards WSW whereas the same location is probably reduced to somewhere between 10-25kW from Brougher.

A significant problem are hills in West Fermanagh, south of Lower Lough Erne that weaken Brougher's signal. Locally, there's relay stations at Gortnalee (near Belleek, which is actually a relay of Limavady via Strabane) and Belcoo to fill the gaps there. My own adventures into Mayo have been few, but I do remember seeing TV aerials aimed at Brougher at Charlestown.

* Yes I know its really in Tyrone

...and I have no problem reminding them where what county it really is in.

Back on topic, if Byte's story has legs, then we might have more potential stories similar to "Mt. Leinster/Preseli" down the line in future.

Mike 1972

lawhec wrote: »

Brougher isn't really underpowered unless you consider 100kW a "ridiculously low ERP", .

Well given that most UK main TX sites are 500Kw (1000kw in a couple of cases). And as you pointed out yourself it struggles to cover Fermanagh (Yes this may be more due to directional restrictions but I did mention ERP)

The old 405 line TX from Strabane despite being further away (being on VHF probably helped) made it somewhat further into Mayo.

Anyway back to Castlebar/Croaghmoyle TBH the thing is more of a gap filler than a relay given the distance between Truskmore and Maghera

watty

VHF maybe has x4 coverage or more. This why RTE abandonded VHF close down. They could not afford enough UHF "transposers" (relays).

Sam Russell

watty wrote: »

VHF maybe has x4 coverage or more. This why RTE abandonded VHF close down. They could not afford enough UHF "transposers" (relays).

Perhaps they should look at using VHF for DTT as it is in the spec, and coverage would be good into NI.

lawhec

Mike 1972 wrote: »

Well given that most UK main TX sites are 500Kw (1000kw in a couple of cases). And as you pointed out yourself it struggles to cover Fermanagh (Yes this may be more due to directional restrictions but I did mention ERP)

The old 405 line TX from Strabane despite being further away (being on VHF probably helped) made it somewhat further into Mayo.

Being pedantic and having little else better to do, I checked the now legacy list (in shutdown mode but not yet fully closed) of the UK analogue transmitter network, of the 51 main transmitters the most common type was a 100kW station (23) with 5 250kW, 13 500kW, 1 870kW and 3 1MW.

Regardless, an ERP increase at Brougher Mountain wouldn't be likely to plug the reception gaps, and with only four dependants, it's has one of the fewest relays of any of the main UK transmitters, Wenvoe and Winter Hill were former 500kW analogue powerhouses but both had/have ridiculous amounts of relays. An increase in tower or mast height would be a much better advantage, but again doing so means having to take more care of international restrictions and thus reducing power further in those directions.

Finally, unlike the Irish Authorities, the UK never has had a policy to deliberately broadcast across the border, so any such reception that occurs is the luck of physics, with UTV and Channel 4 taking advantage of that case so unlike RTÉ, who try to cover all 32 counties where practical, BBC terrestrial reception in Mayo, Sligo, Cavan etc. is of little concern unless there's a chance of it causing interference to domestic services in the Republic. </offtopic>

Kristopherus

godskitchen wrote: »

I thought, correct me if I am wrong, that the deflector site was further down the mountain on the Castlebar side next to a house........

I did not think that it was on top of Croaghmoyle, where there is one main mast which has been there for years (Since the 70's), and a smaller mast that was put up 3 years ago.

That other mast belongs to UPC.

The Cush

watty wrote: »

VHF maybe has x4 coverage or more. This why RTE abandonded VHF close down. They could not afford enough UHF "transposers" (relays).

The other reason was that following an EBU recommendation in the 90's the Odtr directed RTÉ in the early 2000's to retain the Band III frequencies at the five main high-power VHF transmitters for RTÉ 1 & 2 until ASO so that their allocated UHF frequencies could be used to kick-start DTT. I remember seeing this on the old Aertel Technical Information page 530 at the time. Previously posted here.

Sam Russell wrote: »

Perhaps they should look at using VHF for DTT as it is in the spec, and coverage would be good into NI.

The last we heard from Comreg they have no plans to use the Band for DTT.

watty

The Cush wrote: »

The other reason was that following an EBU recommendation in the 90's the Odtr directed RTÉ in the early 2000's to retain the Band III frequencies at the five main high-power VHF transmitters for RTÉ 1 & 2 until ASO so that their allocated UHF frequencies could be used to kick-start DTT. I remember seeing this on the old Aertel Technical Information page 530 at the time. Previously posted here.

A very good later rationalisation. The silver lining of the earlier cloud of ceasing upgrades. It certainly makes 2 x Mux channels available at the main VHF RTE1 & RTE2 sites (or nearby). Of course these Sites were picked for massive Band I coverage. They are mostly not great UHF sites for any big population centres. This is why they had to add Three Rock, Woodcock Hill and Spur Hill. The UHF only, but on all Sites TG4 is less than 95% decent coverage. TV3 are artificially on only 80% as they won't pay for full coverage.

Coverage must have pathetic in some areas before Three Rock, Spur Hill, Holy Hill, Claremont Carn and Cairn Hill added. Those last three of course serve the double purpose of deliberate N.I. Coverage on Analogue. Holy Hill TX is almost in N.I. Limerick City IMO as Broadcast Engineer was Fringe Reception from Maghera or Mullaghanish VHF, depending on part of city before Woodcock started.

Mike 1972

watty wrote: »

Of course these Sites were picked for massive Band I coverage.

Er only Maghera ever used Band 1 The four other original sites used Band 3 from the outset.

Although as mentioned earlier Castlebar (and to some extent Cairnhill) do fill some gaps in coverage.

IIRC Mullaghanish covered/s Limerick reasonably well but a few places had to rely on Maghera

watty

I didn't say they were all used on Band I. But the five sites on Band I pretty much do give National coverage.

The EU is looking at DRM, DRM+ or DAB+ on BandI. Just think, National Mobile coverage with five honking big Band I DRM transmitters. Reception in Spain and Norway under suitable conditions. So naturaly a part of the EU study is examing "DX" interference if Band I is used this way.

Sponge Bob

watty wrote: »

This is why they had to add Three Rock, Woodcock Hill and Spur Hill.

Tonabrocky in Galway and Waterford were added even more recently for the exact same reason.

RTE main transmitters were located and designed for VHFI frequencies around 1958 ...and not even the VHFIII frequencies they now broadcast on.

godskitchen

Kristopherus wrote: »

That other mast belongs to UPC.

What are UPC doing with it?

watty

I'd imagine MMDS?

Mike 1972

Sponge Bob wrote: »

RTE main transmitters were located and designed for VHFI frequencies around 1958 ...and not even the VHFIII frequencies they now broadcast on.

Source ?

Surely the original 5 sites would have been based an ST52 allocations ? Is it even physically possible to accommodate a national network on three VHF frequencies (the Beeb struggled with five)

watty

yes, it's barely possible, just. for only 1 channel and only 5 transmitters. Geography helps

You have 3 transmitters down the west
one in east
one in SE

So maybe

1  Truskmore
                    3 Kippure
2 Maghera
                    1 Mt Leinster
3 Mullaghnish

Numbers are not VHF channel numbers, just to distinguish which share same channel.

You could run 5 separate DRM+ or DAB+ stations on 3 frequencies with a mix of national and regional Radio on Band I covering whole country like that.

Sponge Bob

I think the original plan ( 1950s) was VHF1 only and H/V polarisation with 625 lines = 6 combinations using the 3 x 7mhz channels that were available in VHF1. 6 combinations = 6 transmitters.

They found they had to activate VHF3 for the 405 line transmissions in parallel with 625 lines or TV would not have taken off at all.

Galway

This discussion has now gone way off topic.

Mike 1972

watty wrote: »

yes, it's barely possible, just. for only 1 channel and only 5 transmitters. Geography helps.

Ignoring any UK transmitters -which wouldnt really have been a great idea

Galway wrote: »

This discussion has now gone way off topic.

Fair point

Kristopherus

godskitchen wrote: »

What are UPC doing with it?

As Watty said its for UPC's MMDS service. I had it installed last week (Bye,Bye, Sky:D:D:D). The installer got up on the roof and looked out the Glenisland direction. He explained that he was looking for their transposer. I said I thought theirs was on the Eircom mast. He said, no, theirs was beside the RTE mast.

Galway

Kristopherus wrote: »

As Watty said its for UPC's MMDS service. I had it installed last week (Bye,Bye, Sky:D:D:D). The installer got up on the roof and looked out the Glenisland direction. He explained that he was looking for their transposer. I said I thought theirs was on the Eircom mast. He said, no, theirs was beside the RTE mast.

None of this has has anything to do with the post title. Can it be locked?

watty

Mike 1972 wrote: »

Ignoring any UK transmitters -which wouldnt really have been a great idea

I'd assumed that who ever gave out the 3 channels had Co-ordinated with Wales, N.I. South West England/Cornwall etc.

I didn't show polarisation. Two eastern ones would have polarisation to reduce interference to UK

The Western ones with same channel then have opposite polarisation.

O2, Meteor, Vodafone each only have 3 channels. These 12 channels are also used in N.I. Each has to build a National network with near 95% coverage
yet not have interference with other cells. Each mast or cell typically has all 3 channels, each on a 120 degree or slightly wider beam so that adjacent pairs on same mast overlap slightly. ALL channels must use BOTH polarities H & V as phone aerials can be any angle.

The VHF 5 TV transmitters, one program with 3 channels and single polarisation is easy compared to 3G radio or DTT

12 element

Galway wrote: »

None of this has has anything to do with the post title. Can it be locked?

Why does it bother you so much? It's still interesting. Let the moderators do the moderating!

givecredit

12 element wrote: »

Why does it bother you so much? It's still interesting. Let the moderators do the moderating!

Well to be fair to "Galway" i too keep returning to this thread to read up to date info on Castlebar DTT, only to find people discussing unrelated topic. I think other forums refer to it as "thread hijacking" and its annoying.

watty

No doubt when the Moderator(s) have time they will split the offending posts into a new topic.

godskitchen

To get back on topic.......

If as has been suggested, all the "reflectors" will be gone by 2012, where for example will Castlebar get its signal from then? If it is from higher up the mountain at the large mast then why not just take the signal from there to begin with?

12 element

godskitchen wrote: »

To get back on topic.......

If as has been suggested, all the "reflectors" will be gone by 2012, where for example will Castlebar get its signal from then? If it is from higher up the mountain at the large mast then why not just take the signal from there to begin with?

What do you mean? I'd presume that Castlebar/Croaghmoyle gets its signal from one of the main sites via microwave link.

The Cush

godskitchen wrote: »

To get back on topic.......

If as has been suggested, all the "reflectors" will be gone by 2012, where for example will Castlebar get its signal from then? If it is from higher up the mountain at the large mast then why not just take the signal from there to begin with?

Which signal, the Irish channels or the UK one's via the deflector?

12 element

I think the deflector gets the UK channels from a satellite box. It has nothing to do with the Croaghmoyle site.

STB

The Luas was late this morning.

Sponge Bob

The local news has the story and a well researched piece it is too. Fair play to the journalist/blogger who wrote it.

http://www.mayotoday.ie/2010/08/23/rte-digital-tv-tests-in-mayo-signal-end-for-deflectors/-9671

The Cush

Sponge Bob wrote: »

The local news has the story and a well researched piece it is too. Fair play to the journalist/blogger who wrote it.

http://www.mayotoday.ie/2010/08/23/rte-digital-tv-tests-in-mayo-signal-end-for-deflectors/-9671

I agree with that, good article. Better researched than some "experts" we have posted about recently.

Including the brand names Saorview/Saorsat would have provided a reference for those new to DTT to learn more on the internet.

Some might assume reading the article that once the deflectors shut down the UK channels would be available on DTT/Saorsat, a reference to freesat or free-to-air could have been included.

Sam Russell

Also the author might have mentioned that Freesat will allow free access to most UK TV services, removing the need to pay a subscription for TV services.

Saoview = GOOD
Saorsat = Good but not yet
Freesat = Good
Freeview = BAD
Freeview HD = Good.

watty

However while Saorsat isn't available at "Soft launch" Saorview only launch time, it seems likely that the "full public launch" is after Saorsat starts, unless Kasat fails.

It should be emphasised that Freesat HD box or Freeview HD boxes don't need HD TVs and give all the channels. The non-HD versions don't.

Saorsat and Saorview has "HD" boxes or TVs as the minimum. Again an actual HDTV is optional.