DAB in Ireland: RTE multiplex closed

watty

252 is to be switched from AM to DRM. As I posted some while ago. There is talk of MW too, but my understanding is that the former Atlantic 252 site is first. The RTE pre-DRM co-channel interference monitoring in London has all been on 252.

This tender could be for the MW site of course. The current 252 transmitter may be convertable to DRM as it is not that old.

There may not be a trial as such, but perhaps some hours a day DRM then complete DRM instead of AM on 252.

It will be great for listeners in UK and France. In Spain the Algerian Co-channel may block it.

L1011

It'd be surprising that they'd be willing to drop output power on 252 - they have 2x250's there now.

I'd say its more likely for 612

lawhec

Wasn't the allocation for 612kHz rated for 100kW only? Don't know if the ITU have received an application to change the power output of the allocation.

Maybe 567kHz might be tested? I would hazard a guess that with 252 designed for "overseas" reception and that most places now carry FM where 567kHz is meant to cover, they'll try that? Maybe when it was switched off a while back they were able to gauge feedback?

612kHz makes half sense as I believe that when RTÉ shut that transmitter down at Athlone a couple of years ago, much of the transmission equiptment was said to be fairly old.

252 is held by importance by many in importance by Irish dispora in Britain. Remember the large amount of complaints when Saturday and Sunday sports coverage was taken off LW for a time.

watty

Definately for 252 Summerhill. Can't reveal source.

watty

Interesting DAB, MP3 & FM Radio
http://www.reghardware.co.uk/2006/04/13/oono_minidab/

lawhec

DAB, in the form of BBC National and Digital One are now broadcasting from Presely...

http://www.digitalone.co.uk/press/display.asp?id=250

bkehoe

Tullamore is the site referred to in the tender docs.

As for 252, it hasn't been running at 500KW since RTE R1 started to be broadcast from it at least. RTE have it cut back to approx 300KW to save on the ESB bills!

watty

I suppose RTE can broadcast on 252 in DRM wherever they want. But it definately 252 that is going DRM first. Had it from senior RTE source. Maybe they will shut down the Trim site when new Tx at tullamore?

bkehoe

The existing setup in Tullamore isnt that old, though it isn't solid state. I think the main reasons for upgrading is for increased power efficiency (solid state transmitters are significantly less wasteful of energy than 'conventional' valve based transmitters) and, of course, DRM. It's not that difficult to use any AM transmitter for DRM - in theory 252 should be able to do it as is with some modificatiions, though I'll make some inquiries to confirm that.

Attached pics - tx engineers need to know a bit about plumbing to maintain the 252 transmitters! This is where most of the wasted energy ends up - giant radiators and fans for cooling the transmitters.

bkehoe

bkehoe wrote:

The existing setup in Tullamore isnt that old, though it isn't solid state.

Two questions:

While Tullamore was off the air was the TX upgraded to solid state?

Is the Athlone 100kW Continental rig solid state or valve? I'd assume its still there, even the original Marconi one is!

DMC

DAB CHANGES.

Changes on Three Rock certainly...

With no action, a rescan of the band shows that "RTE DEMO" appears on the display, and only 4 channels found...

But when you get to tune in the channels, only two are audible. RTÉR1 and RTÉ2FM... (on my Roberts RD-5, É appears like the greek letter theta.. Θ... ) doing a manual tune, RTΘONE and RTΘTWO appears, but with no audio.

Audio is down to 160kbps, Date and time is correct and scrolling text is "This is the Radio 1 (or 2FM) DAB service from RTΘ on test."

byrnefm

After reading DMC's post, I decided to have a look for myself to see what's left on air on DAB and how it's changed since Thursday 11, when I last tuned into DAB. Here's the details that my LaGIO R105 gives:

# stations on 12C: 2 (was 6)

Details of each station on air (much of which is a recap of what DMC found)

If you tune in manually to find a multiplex, 12C now reports as 'T M' instead of 'Conf 1'.

Letting the radio auto-tune, I get (scrolling through each of the options on DAB, ie. name, channel, description, etc)

RTÉ Radio 1
This is the Radio 1 DAB Service from RTÉ on test.
Signal Error 0
160kbps Stereo
12C
18-05-2006
RTE DEMO
Varied Speech

RTÉ 2 fm
This is the 2fm DAB Service from RTÉ on test.
Signal Error 0
160kbps Stereo
12C
18-05-2006
RTE DEMO
Pop Music

This contrasts with last week where apart from there being 6 stations at 192kbps, the rest of the data was blank (or in the case of the date, wildly inaccurate). The 'É' comes out correctly on the LaGIO, as it turns out. I also checked the L-band for the fun of it but nothing there.

Radio 1 only had speech on at the time when I listened to it this evening. Maybe it's just me but 2FM sounded worse than before in that the music sounded a very little bit muddy, despite perfect signal strength.

I suppose I can't complain really - the DAB tests were due to have ended nearly two months ago!

I also notice that digital radio gets a mention in the business section of the Irish Times this morning, saying in it that while RTÉ have been testing DAB since the beginning of the year, that they don't seem to be pushed on rolling it out to other parts of the country. Surely that's because it's still in its testing phase?

lawhec

byrnefm wrote:

After reading DMC's post, I decided to have a look for myself to see what's left on air on DAB and how it's changed since Thursday 11, when I last tuned into DAB. Here's the details that my LaGIO R105 gives:

# stations on 12C: 2 (was 6)

Details of each station on air (much of which is a recap of what DMC found)

If you tune in manually to find a multiplex, 12C now reports as 'T M' instead of 'Conf 1'.

Letting the radio auto-tune, I get (scrolling through each of the options on DAB, ie. name, channel, description, etc)


This contrasts with last week where apart from there being 6 stations at 192kbps, the rest of the data was blank (or in the case of the date, wildly inaccurate). The 'É' comes out correctly on the LaGIO, as it turns out. I also checked the L-band for the fun of it but nothing there.

Radio 1 only had speech on at the time when I listened to it this evening. Maybe it's just me but 2FM sounded worse than before in that the music sounded a very little bit muddy, despite perfect signal strength.

I suppose I can't complain really - the DAB tests were due to have ended nearly two months ago!

I also notice that digital radio gets a mention in the business section of the Irish Times this morning, saying in it that while RTÉ have been testing DAB since the beginning of the year, that they don't seem to be pushed on rolling it out to other parts of the country. Surely that's because it's still in its testing phase?

My guess is that RTÉ are looking to see what is the lowest bitrate they could get away with for their stations on DAB. If 2FM is sounding "muddy" then I wonder if the feed being used was the same as the FM one (DAB feeds are recommended to have a seperate one to that of FM in terms of music compression), also they'll probably trial "Joint Stereo" at 160kbps at some point, which is what the vast majority of music stations on DAB in the UK use with a bitrate of 160kbps or less.

DMC

Its joint stereo here.

byrnefm

How can you tell if it's in stereo or joint stereo? My receiver doesn't specify the difference, only if it's in mono or stereo.

lucernarian

watty wrote:

I blame the River boyne. The Amateur repeaters vanish also crossing Drogheda Town

Sorry for the time lapse...

What do you mean by "The Amateur repeaters vanish also crossing Drogheda Town"??

Is Mt. Oriel an amateur repeater? That's where Drogheda gets its Chorus, and LMFM. I presumed RTÉ would have a transmitter there too...

DMC

byrnefm wrote:

How can you tell if it's in stereo or joint stereo? My receiver doesn't specify the difference, only if it's in mono or stereo.

Mine does, but I don't know how you would on yours.

watty

To_be_confirmed wrote:

Sorry for the time lapse...

What do you mean by "The Amateur repeaters vanish also crossing Drogheda Town"??

Is Mt. Oriel an amateur repeater? That's where Drogheda gets its Chorus, and LMFM. I presumed RTÉ would have a transmitter there too...

Ridge Capard / Slieve Bloom (NW of Portloise)
Clermont Carn (Nrth Dundalk)
Three Rock (SW Dublin)

All can be received on N1 and N2 on North and South side of Boyne. (N2 better).

lucernarian

Did a bit of research and it seems that we get our television directly from Claremont Cairn. Mt. Oriel is just a deflector (not sure what that is). For some strange reason, my TV3 and TG4 reception is not as good as RTÉ 1 and 2.

Thanks for the info.

DMC

Mt. Oriel also transmits LMFM on 95.8, one of the stronger ILR transmitters around the country.

L1011

To_be_confirmed wrote:

Sorry for the time lapse...

What do you mean by "The Amateur repeaters vanish also crossing Drogheda Town"??

Is Mt. Oriel an amateur repeater? That's where Drogheda gets its Chorus, and LMFM. I presumed RTÉ would have a transmitter there too...

Watty means either ham (amatuer) radio or TV repeaters; nothing to do with "official" transmitter networks

To answer what you mentioned below, a deflector is a transmitter that effectively just "deflects" signal - e.g. it receives it on one channel, possibly boosts it, and transmits it otherwise unaltered on another. In Irish terms, it usually refers to a system to get the Northern Irish/Welsh channels further away from the border/coast than might be expected

I don't know whats on Mount Oriel bar ILR and Chorus MMDS but I wouldn't think a deflector in that term would be required. It could be an MMDS deflector ("beam bender", after an actual maker of MMDS deflection kit in the states) for Chorus.

watty

Well they are "official" in that Comreg issues licences for them and unlike Garda, the public is legally allowed to listen to the traffic with scanner.

Also "official" in sense that you need a licence to talk on them.

Unoffical in sense that no comercial organisation pays for them. Voluntary subscription gets them installed and keeps them going.

MMDS "beam benders" or "Deflectors" are simply repeaters.

lucernarian

Mt. Oriel has FWA broadband providers, the usual mobile phone companies, and some form of National Radio retransmission (RTÉ 1 is strongest here on 95.2). There is the deflector there aswell of course. Thanks for the info.

One other question: What is the difference between a relay and a deflector?

DMC

To_be_confirmed wrote:

and some form of National Radio retransmission (RTÉ 1 is strongest here on 95.2).

Hardly. Clermont Carn not 20 miles away as the crow flies in the Cooley Mtns is on 95.2.

lucernarian

DMC wrote:

Hardly. Clermont Carn not 20 miles away as the crow flies in the Cooley Mtns is on 95.2.

My apologies, I read something on a website incorrectly. It's just LMFM that's used.

byrnefm

Err, I think we're going a bit off-topic now?

maisflocke

byrnefm wrote:

Err, I think we're going a bit off-topic now?

Very much so....

Right, me thinks that DAB will never be the FM replacement that the developers thought it would become... It's old technology (developed in the late 80's / early 90's) and with exception of the UK, it has not established itself at all on the continent.. in fact, radio stations in the northern half of Germany are actually returning their DAB broadcasting licences to the broadcasting commision, because the project is stuck in a rut going nowhere... Their preference at the mo is to explore DVB-T Radio, which is already up and running in Berlin.
Me thinks that the RTÉ tests are a waste of time and money, particulary when the future of DAB -even in the UK- looks so cloudy....

Your views?

DMC

We had this discussion a few months ago when digitalradiotech was here, so nothing much has changed since then.

We could talk about this until we are blue in the face again, so I wont, my views are there. You can start a new thread, if you like.

I'd prefer if this thread was just about reception reports/discussion about the trial itself, if the mods want to do a job around here....

watty

To_be_confirmed wrote:

Mt. Oriel has FWA broadband providers, the usual mobile phone companies, and some form of National Radio retransmission (RTÉ 1 is strongest here on 95.2). There is the deflector there aswell of course. Thanks for the info.

One other question: What is the difference between a relay and a deflector?

originally
Relay = legitimate rebroadcast. RTE call them Transposers.
Deflector = euphemism for illegal rebroadcast.

Conceptually (and sometimes technology wise) they are the same thing.

byrnefm

No change since in the broadcasts (just RTÉ Radio 1 and 2FM). I wonder how much longer RTÉ are planning on running the tests - or if this is their way of doing a 'quiet launch'?

I was over in N. Lincolnshire last week and got a total of 38 stations on DAB .. however, some were encoded as low as 64kbit and only one (Virgin) was as 'high' as 160kbit (apart from BBC Radio 3, I think, which is usually 192kbit).

[edit] Just noticed on electricnews.net that RTÉ appear to be extending their DAB trial alright: http://www.electricnews.ie/frontpage/news-9702288.html

Excerpt:

National television broadcaster RTE hooked up with BTRadioScape on Friday to bring live digital TV signals to Irish mobile phones. The service will be piloted in Greater Dublin and North East areas with a limited service of two TV channels: RTE One and RTE Two. The trial will also broadcast digital audio band (DAB) radio to mobile phones beginning with RTE 1 and RTE2fm. The scheme is based on the DAB-IP broadcast system. It is designed to eliminate the network congestion associated with some existing mobile TV services and allows an unlimited number of users at any one time to access live digital TV and digital radio.

[/edit]