[ninja900]

In response to an aside on the Saorsat thread http://www.boards.ie/vbulletin/showp...postcount=1829 , probably more appropriate to here.

Originally Posted by lawhec

I stand to be corrected here, but I believe that RTÉ1 was launched on UHF (E40) at Carin Hill several months before RTÉ2 went live.

No idea. But we definitely got a UHF aerial installed in 1978 in the run-up to RTE2, pointed at Three Rock, and we got excellent RTE1 off it also, but I can't be certain the RTE1 UHF was there at the same time as the RTE2. It was certainly there within a year or two.

I'm not entirely sure if Three Rock was fired up before RTÉ2 went live as well, but it was opened in the same year (1978).

Three Rock RTE2 was definitely (as definite as a 7 year old can be 33 years later, but with so few TV channels, any change was memorable!) there before RTE2 launch, we could get RTE2 test transmissions on it we couldn't get on cable at the time.

Considering the Irish terrain and the lack of immediate need for any more TV networks (RTÉ struggled a lot during the 80's filling schedules for RTÉ2)

Yeah, imagine our disappointment when RTE2 turned out to be mostly BBC / ITV repeats with the odd Irish-languange programme thrown in! I think the latter was what motivated my mam to get my dad to get the RTE2 aerial... of course once it launched it was on cable anyway. Nobody called it 'cable' then. It was 'the pipe' or if you were a bit posh 'the communal aerial'. We got bills from 'MCA Marlin Communal Aerials' who ended up in Cablelink.

it made sense to stay with VHF as a transmission backbone with UHF where needed. A complete conversion to UHF would have been costly without any immediate benefit, and that a significant roll out of relay stations would have been required to fill in coverage gaps. It wasn't until TnaG came along in the mid-90's that many small relay stations where UHF coverage from main transmitters was inadequate sprung up.

Irony was that many in the west needed a new aerial to get 'their' station, anyone in Dublin with a Three Rock aerial (or cable) didn't need to do anything!

[MarkK]

Originally Posted by ninja900

Yeah, imagine our disappointment when RTE2 turned out to be mostly BBC / ITV repeats with the odd Irish-languange programme thrown in!

Don't forget those wonderful "National Film Board of Canada" short films

[ninja900]

Ahh yes. There was the odd excellent one ( http://en.wikipedia.org/wiki/Cosmic_Zoom ) but lots of dross. I remember one film about safe driving, RTE remembered to announce beforehand that any references to 'keep right' should be construed as 'keep left' and vice versa, would've been easier to tell everyone to watch a reflection of the TV in a mirror

[zg3409]

>We got bills from 'MCA Marlin Communal Aerials' who ended up in Cablelink.

I know of a house that still has an "RTE Relays" labelled pipe TV outlet. UPC are recabling the area at the moment and their policy is to replace them if they visit any house. I'm making sure to get the old one some day.

On the cable system in Kilmacanogue one channel was a video camera pointed at the main road to show the traffic! This was a small private system to give RTE coverage where there was none, and probably still isn't. Not sure if it's still going.

[Digifriendly]

Wasn't RTE2 launched on the same day Munster beat the All Blacks and so there was no proper OB coverage of that famous day, only a filmed version?

[watty]

Originally Posted by Karsini

Correct, it was 1978 before UHF was rolled out in Ireland. Three Rock was one of the first, if not the first.

Carn Hill, Longford was before 1978. I know because it was same channel as Scotland and one night BBC closed earlier than RTE and Divis was rebroadcasting RTE 1. Can't remember if 1975 or 1976. But by 1978 I wasn't working at the BBC any more. Technical steps taken to make sure it couldn't happen again.

[Mike 1972]

Kinda suprising that the Beeb would use an off air UHF feed for a big transmitter like Divis. Apart from the technical deficencies of such an arrangment surely there were security iimplications (particularly given the time and place .....)

As for RTE between the they seemed to undergo a complete policy shift regarding UHF. Before 1978 it was regarded as something mysterious and frightening never to be used even where it would have made sense.

Twenty years later they had embraced it with the zeal of the convert converting old VHF relay sites across the land to UHF for no apparent reason.

[Antenna]

Originally Posted by Mike 1972

Kinda suprising that the Beeb would use an off air UHF feed for a big transmitter like Divis.

It surely would only have kicked in as a backup if the link from the Belfast studio failed, which was probably very rare.

[ninja900]

Originally Posted by Mike 1972

Twenty years later they had embraced it with the zeal of the convert converting old VHF relay sites across the land to UHF for no apparent reason.

Maybe the old VHF relay transmitters were reaching end of life, and it was easier/cheaper to replace them with UHF ones?

I think they said that this was part of the reason Athlone MW was shut down, the old transmitter was ancient and would've needed to be replaced if MW was kept going.

[ninja900]

Originally Posted by Antenna

It surely would only have kicked in as a backup if the link from the Belfast studio failed, which was probably very rare.

That prompted me to go look up a document I found a couple of months ago about how the BBC network was linked up in the old days.

According to this PDF doc from 1958 here, page 26, Divis was fed at that time from a UHF link (no UHF broadcasting then) from Snaefell in the Isle of Man, which was fed off-air from Holme Moss!

I presume a landline came along later...

[watty]

Originally Posted by Antenna

It surely would only have kicked in as a backup if the link from the Belfast studio failed, which was probably very rare.

It kicked in briefly every night when BBC NI closed. It would find then that Scotland had closed and then shut down. Normally BBC1 and BBC2 fed by "land line" from Ormeau Avenue, even if the content was from London. Certainly in mid 1970s Snafell wasn't used, only Scotland.

RTE <-> BBC was a two way full duplex FM microwave link, with a relay at "Dead Man's Hill". By ringing Deadman's and feeding tones* you could reverse both links (mechanical Microwave switches) in case one was broken, then it could be used only in one direction. You could also "loop back" at Deadman's so Belfast and Montrose could each see their own signal.

The circuit was the only way for RTE to get or contribute live video outside Ireland. Spain had the Teleport for US link, so USA to or From RTE had to be via Spain, France, England, Scotland, Divis, BBC Ormeau Avenue, Standing Stones, Deadman's Hill, Dublin.

In event of Hostile take-over of BBC NI the wire connections could be destroyed and then Divis would go over to Rebroadcast.

ALL the transmitters in whole UK had automatic fail-over to UHF off air if the "land line" failed or local Broadcasting studio had a failure of any kind.

[* The tone box was lost before my time at BBC, so you whistled and watched the video monitors to see what was happening. The link quality was slightly better one way than the other so you'd whistle as the screen swapped beween perfect RTE test card, your own looped test card or less than perfect RTE test card and leave it at which ever setting was desired.]

[Mike 1972]

Originally it was planned that RTE2 was to be a UHF only network but it was found that through precision frequency offsetting it was possible to squeeze (most transmitters of) two networks into Band 3

Doing so however lead to co-channel problems (between Maghera and Kippure) across a large chunk of the Midlands (despite different polorisation) so Cairn Hill was used as a filler partially for the aforementioned reason but also because signal strengths from the existing trasmitters were fairly poor across much of the target area anyway.

A third benefit of Cairnhill has that it brought RTE on UHF to parts of Fermangh Tyrone and even Armagh where previously it was only available (if at all) on VHF which many sets sold in NI couldnt pick up.

One downside is that RTE 1 (E40) caused image channel problems on some TV sets trying to recieve Channel E31 (nine channels lower) from Divis

[lawhec]

Originally Posted by Mike 1972

Doing so however lead to co-channel problems (between Maghera and Kippure) across a large chunk of the Midlands (despite different polorisation) so Cairn Hill was used as a filler partially for the aforementioned reason but also because signal strengths from the existing trasmitters were fairly poor across much of the target area anyway.

At the time of RTÉ2's opening, RTÉ1 at Maghera was only on Band I (Channel B) and Kippure was on Channel H and RTÉ2 didn't start broadcasting from Kippure until a low power transmitter was put in place there on Channel J in I think 1983. Not sure if RTÉ2 from Maghera was on Channel E or H from the start there, but the eventual Maghera & Kippure co-channel use with offsets and differing polarity on both RTÉ1 & RTÉ2 on Channels E & H was long after Carin Hill opened, possibly in the early 90's as RTÉ1 started simulcast on Channel E from Maghera in 1992 alongside Band I. Not sure what date Kippure went from H & J to E & H.

[Mike 1972]

RTE2 was always on H from Maghera (RTE1's Ch E from the same site didnt appear until c 1993) RTE 1 was always oin E from Kippure (bar the very early 405 line only days when it was on Ch 7)

Not sure why it took so long for RTE1 to move to Ch E. Prior to 1985 there may have been 405 line transmissions from the UK which required protection (Indeed this is the reason why RTE1 from Maghera formerly used Ch B instead of the originally planned Channel A which would have clashed with Divis)

[watty]

Almost All 405 in UK was running till 1985. I know a guy that worked for BBC and RTE NL (not at same time ) and was involved on site for both turning off 405. But Maghera was certainly still on Band I in 1999.