RTE to probe Three Rock transmitter breakdown

Antenna

I spotted this in last Sunday's Sunday Independent (January 15, 2006)

RTE to probe service breakdown
RTE are to investigate why the station went off air in the Dublin area for about 15 minutes on Friday night.
Many viewers missed the start of the Late Late Show due to problems with a transmitter at Three Rock, in the Dublin Mountains.
The transmitter picks up a signal from Montrose and this is then relayed to the greater Dublin area.

Anyone know why it happened? Was it just RTE1 that went off or were other TV/radio stations affected too?!

DMC

Did anyone notice?? Three Rock is probably the least viewed transmitter in the country.

Mossy Monk

Antenna wrote:

Many viewers missed the start of the Late Late Show due to problems with a transmitter at Three Rock, in the Dublin Mountains.

i wonder how many actually watch RTÉ through an aerial from Three Rock

Telefís

Where is Three Rock out of interest - is it near Kippure?
And what is its purpose?

DMC

Do you live in Dublin, Telefís? You can see it if you look south on a good day!

Its in the Dublin mountains, and it was used to fill in the black spot along the east coast that Kippure couldn't reach (Dalkey etc) More or less used to replace the 405 relay on top of the mast in RTÉ's grounds at Donnybrook.

L1011

Its also powerful enough in the right direction to ensure that you shouldn't need more than a setup aerial in Dublin, although considering >90% of Dublin has cable...

Telefís

Righto - thanks. Doesn't south Dublin go down into a hollow, and there was some embarrassment when RTÉ first started because the RTÉ execs living around Donnybrook/Mount Merrion/Dalkey couldn't even receive their own station! Is it this the relay on the Montrose Mast that Three Rock replaces?

Okay so which is Three Rock - this is a pic I took of them from Crumlin Village a while ago

Round Cable

I have a set top aerial with booster, RTÉ 1/2 (with some ghosting) come in fairly well, although TV3 and TG4 leave a lot to be desired, DTT will improve this situation.

DMC

Telef&#237 wrote: »

Righto - thanks. Doesn't south Dublin go down into a hollow, and there was some embarrassment when RTÉ first started because the RTÉ execs living around Donnybrook/Mount Merrion/Dalkey couldn't even receive their own station! Is it this the relay on the Montrose Mast that Three Rock replaces?

Okay so which is Three Rock - this is a pic I took of them from Crumlin Village a while ago

The one with the UHF antenna at the top. (the tallest one)

Yes, it more or less replaced the 405 service at Montrose, I think as RTÉ 2 couldnt be accomodated at base camp. Along with Cairn Hill in Longford, it was RTÉ's first UHF tx.

BrianD

Three Rock Mountain apparently has a poor electric supply system that has no redundency. This is surprising given the number of aerials poking out of the mountain.

seamus

TBH, I wouldn't be suprised if some drunken scumbags managed to do some damage, especially given that it was around 9 on a Friday night.

lawhec

DMC wrote:

Did anyone notice?? Three Rock is probably the least viewed transmitter in the country.

I dunno about that. Even though Dublin has around 80-90% cable takeup that would still leave around 100,000 to 200,000 still needing a terrestial signal (excluding Sky) and even with cable, there's probably things like kids bedrooms, student bedsits etc. which might only be able to access a terrestial signal.

I'm surprised that a site like Three Rock doesn't have any electricity redundancy considering the amount of services that use the site, none of which use an extraordinary amount of power. None of them have any diesel backup generators there?

marksi

There is some technical reason that I cannot remember why analogue television transmitters cannot work off generators. Most have dual, independent power supply paths.

lawhec

In the 405 line days, there were stand-by generators for most of the transmitters in the case of a power cut in the UK (dunno about RTÉ) but wern't used for 625 line UHF. They were however re-introduced when DTT was started as a backup supply for them. My guess is that the powers required for UHF broadcasting mean that large generators would be needed and rather unfeasible. Still, they are used for some transmitters when they undergo electrical maintenance and Three Rock itself isn't a terribly powerful UHF transmitter compared to Kippure or Mt.Leisnter.

Telefís

Interesting.

Which of the remaining two in the pic then is Kippure?
I had always thought the elegant Three Rock mast was it - surely the most famous transmitter in Irish broadcastng isn't that stumpy yoke in the middle?!

DMC

Neither. Different hill.

L1011

As DMC said, wrong mountain

Kippure is on, err, Kippure Mountain. Three Rock is on Three Rock Mountain

RTÉ have some imaginative names, you see

Ulsterman 1690

RTE are to investigate why the station went off air in the Dublin area for about 15 minutes

Transmitters in other parts of Ireland have been known to go off for hours, days and (in extreme cases) weeks at a time without newspaper stories about "investigations" being carried out :rolleyes:

There is a perception in some parts of Ireland that RTE is basically a local TV station for for "Dublin Four" that just happens to be carried on some very big deflector systems. This perception seems to be justified here.

Its no suprise that the electricity supply in the Dublin mountains isint up to much. Its pretty typical of any thinly populated area (albeit near some pretty densly populated areas) with difficult terrain but it is a suprise that a fairly major transmission site wouldnt have its own backup generator even if it necessitated thetransmitters running on somewhat reduced power output when powered from the generator.

And theres some pretty big diesel (or gas) powered generators on the market these days.

80% or so of Greater Dublin may be on cable but what about
1) Parts of the City that dont have cable
2) People who dont subscribe to cable (Maybe they can get BBC on an aerial or have a dish)
3) Kitchen/Bedroom TV's not on cable
4) Flats/Bedsits etc -Although in Dublin many of them have cable (unofficially in a lot of cases)
5) People living outside the greater Dublin area (but within the three rock footprint)

Oh and where do the cable headends get RTE from

DMC

To clear matters up.... here's a Google Earth file showing where RTÉ's transmitters are. Initially, I've included the main sites, I'll add in the relays over time.

If you dont have Google Earth, its great and free.

http://earth.google.com/

Then download the file attached here, its zipped, so extract it, then double click the KMZ file, and it should open.

NOTE: Google Earth really needs broadband to operate.

marksi

As an example, there is no generator back-up for analogue television services from Divis, but radio and DTT services are backed up by a generator.

Antenna

Ulsterman 1690 wrote:

Oh and where do the cable headends get RTE from

They possibly have a system to automatically switch over to a receive of an alternative transmitter (Kippure?) if Three Rock goes off?

Though I vaguely recall reading that Cablelink in Dublin (as it then was) had a DIRECT link from RTE? maybe someone could confirm or deny this?

Telefís

It would certainly make sense. Didn't somebody say this week that TV3 is linked directly to the Montrose mast underground?

Just a question about Clermont Carn - not a technical one as such, but rather simply what is its correct spelling?!
Even RTÉ literature and documentation differs in its spelling - is it Clermont Carn or Clermont Cairn?

stylers

Howye Lads,

speaking of all these transmitters, how close can one usually get to the sites up the hills and mountains ?. I was thinking of visiting a few this year. the brother and a few lads were up on mt Leinster last year, and the gates were open, so they wandered in for a look (there was an RTE van there apparently). He took a few photo's with the digital, but could'nt figure out why there was a weird pattering on the photo's when he got them on the PC :rolleyes:

Owen..

Ulsterman 1690

Ive been to a few RTE, deflector and Irish commercial radio (legal and otherwise) sites are they are usually fairly acessable (albeit often over pretty bumpy mountain roads) although usually there is a wall or high fence around the actual site itself

And yes sometimes the gates are left open (even when noones there) and or there is a gap in the fence or carelessly discarded ladder enabling one to climb into the site .

However if one is going to access the site itself please have a bit of respect and dont steal, vandalise or interfere with anything since it will only lead to them increacing security and spoiling things for future visitors.

Oh and be careful (nothing like an injury -especially when followed by silly lawsuits for making them increace security either)

CCTV is fairly rare in these places but is used by some MMDS companies and some of the more paranoid two way radio company repeater sites.

BBC NI sites tend to be more security concious with the last few hundred meters up to the site often over a private road with a locked gate making vehicular access impossible. (Not suprising given at least one BBC site was the subject of a terrorist attack onetime)

lawhec

Ulsterman 1690 wrote:

BBC NI sites tend to be more security concious with the last few hundred meters up to the site often over a private road with a locked gate making vehicular access impossible. (Not suprising given at least one BBC site was the subject of a terrorist attack onetime)

That was Brougher Mountain - a number of BBC engineers were killed by the IRA there, supposedly they were mistaken for an Army patrol. It was in 1971 I think.

It was before my time but from what I have read, it meant that visits to the site were made only in emergencies for several years, and made Brougher the last main site to have colour TV introduced very much for that reason.

byte

Northern Correspondent wrote:

That was Brougher Mountain - a number of BBC engineers were killed by the IRA there, supposedly they were mistaken for an Army patrol. It was in 1971 I think.

It was before my time but from what I have read, it meant that visits to the site were made only in emergencies for several years, and made Brougher the last main site to have colour TV introduced very much for that reason.

Wow, didn't know that. Some interesting facts.

Nice Google Earth link, DMC, can see Kippure and 3Rock masts fine. Other masts like Truskmore are non-existant. That would be down to no proper aerial photography of the area I assume.

The closest mast I've come to is the small one in Garrison, Fermanagh which was way into the middle of a forest, and when I was drivign through the forest, I spotted the mast, and went in search of the road up to it! I found it alright but it was securely locked.

L1011

Spur Hill is very visible too, Holywell Hill has clear but not clear enough imagery

Antenna

Antenna wrote:

They possibly have a system to automatically switch over to a receive of an alternative transmitter (Kippure?) if Three Rock goes off?

Though I vaguely recall reading that Cablelink in Dublin (as it then was) had a DIRECT link from RTE? maybe someone could confirm or deny this?

A long time ago ,I think it was 1987, there was a strike at UTV and cable link or RTE relays switched to HTV Wales in Dublin for a while.
Twas great to have it.Felt like I was at home.

SPDUB

Antenna wrote:

They possibly have a system to automatically switch over to a receive of an alternative transmitter (Kippure?) if Three Rock goes off?

Though I vaguely recall reading that Cablelink in Dublin (as it then was) had a DIRECT link from RTE? maybe someone could confirm or deny this?

Well when RTE was closing down overnight and showing pages from Aertel I discovered when I tuned in Three Rock ,as a backup source, that a couple of minutes after programmes ended that Three Rock went off the air.About the same tiime I also recall reading that Cablelink had a direct link to RTE

Ulsterman 1690

Maybe it was from the (pre-Cablelink) days of "RTE relays" ?

L1011

Even when it was Cablelink, it was half-owned by RTE, so its entirely possible they were pullling direct from Montrose into the head ends.

SPDUB

Ulsterman 1690 wrote:

Maybe it was from the (pre-Cablelink) days of "RTE relays" ?

No it wasn't from as far back as then because about two or three years previous to that there was a sound problem on RTE one night from Three Rock and the fault also happened on the cable system and Cablelink put up a message saying that the fault was at the Three Rock transmitter

Here's a shot of the RTÉ mast in Listowel. VHF transmissions were supposed to end at this site around 1999 but its still there today! Why I don't know.

There's also some Meteor mobile cells down the mast.

bk

I remember reading somewhere that RTE have or will soon have a fibre optic link direct to NTL for digital.

Either way NTL can always pull RTE down from Sky Satellite, like they do with all the other channels.

aphex™

bk wrote:

Either way NTL can always pull RTE down from Sky Satellite, like they do with all the other channels.

They get Channel 4 and ITV from Divis

testicle

Karsini wrote:

Here's a shot of the RTÉ mast in Listowel. VHF transmissions were supposed to end at this site around 1999 but its still there today! Why I don't know.

Military?

aphex&#8482

aphex&#8482 wrote:

They get Channel 4 and ITV from Divis

I don't know about the current state but they certainly did at one stage. I remember back in 1994/95 watching UTV on Cablelink and suddenly a colour bar test card came on the screen with the message:

		Cablelink

There is no transmission from Divis transmitter, N.I.

I don't remember the exact wording but it was similar to that. At the time I wondered why but in later years I knew exactly what it meant.

SPDUB

They still receive the signal from Divis and you can tell what transmitter you are receiving by putting the teletext on to Page 100 on ITV or CH4 and pressing the Reveal button on your remote

In the bottom right corner of the blue box at the top of the screen which says "Teletext ITV1 Northern Ireland " the three letter DIV appears indicating you are receiving the Divis transmitter

L1011

And the reason they pull it off Divis rather than satellte? Teletext.

SPDUB

MYOB wrote:

And the reason they pull it off Divis rather than satellte? Teletext.

They also seem to have the problem also that if they take the satellite feed the picture is "zoomed in " cutting off captions

SPDUB

SPDUB wrote:

They still receive the signal from Divis and you can tell what transmitter you are receiving by putting the teletext on to Page 100 on ITV or CH4 and pressing the Reveal button on your remote

Actually that will tell you Divis even if you are getting it from Brougher mt or any other NI tx as they are all fed from Divis.