DAB in Ireland: RTE multiplex closed

byrnefm

I didn't notice it from the bit of listening to Radio 1 that I did - Today FM's was fine, at any rate. I did notice that the sound quality from at least one of the ads was awful - like an .mp3 that was set to 64kbits or lower. For the most part, however, I wouldn't have been able to tell the difference between the DAB version of Today FM and the analog version.

I noticed that the signal strength of Three Rock was turned down about 2/3 for about 20 mins at 2:35pm (I think) and then went up to 2/3 signal strength. When I tried later again at 8:30pm, it back back to full. I know that it was Three Rock as it's impossible to listen to the portable sitting down in my room with a Claremont Carn signal.

watty

The bubbling could be over processed audio feed?

If there is any typical processing on the audio (IMO an evil thing even on FM, which can cope), then the MP2 encoding is impared.

IMO at about 192k there isn't any difference between joint stereo MP2 and MP3. It is really only at lower rates that I don't use that MP3 performs better.

We use 256k MP3 for our home networked music library, but direct CD to Atrac2 for the minidisc player as going via MP3 even at 256k is noticably poorer.

I think standards even for audio on VHF FM have fallen a lot since I was a comms centre engineer in 1976, so it is too late to worry much about DAB.

160k MP2 will sound OK with some material, but not if it is processed at all. Only a little advange to MP3 or Atrac2 (supposed at 160k to be equal to 192k, but I think it depends on content).

IMO 128k MP2 joint stereo sounds worse than 128 MP3 joint stereo, but I wouldn't encode that low ever again on MP3 either. Either codec with very high separation stereo (un-natural) or dual channel audio is effectively 64K and terrible.

I can't compare other codecs as I havn't used them to encode myself or in some cases don't have them.

I've used Tmpenc for MP2 and Media Player 10 and "Lame" for MP3. Also I can compare FM radio with Satellite MP2.

Today's over processed average FM radio station compares very poorly with 192K MP3, 160K Atrac2, CD Audio or home encoded MP2 played on a DVD player.

(I use MP2 encoding for SVCD and DVD, mostly my own material, some source from 8mm analog Camcorder, some CD Audio and some home recordings in Wav format at CD Red book compatible settings using Phonic Mixer desk and Creative Sound card).

DMC

Three Rock off-air this evening.

watty wrote:

The bubbling could be over processed audio feed?

Possibly. I think the feed they are using is the one they use for satellite? I must check the delay when its back on-air...

watty

RTE Satellite doesn't sound great either.

lawhec

According to a post on D*****l S*y the DAB audio feeds to Clermont Carn are taken from the same feed as FM.

waiguoren

I couldn't receive the 6 DAB channels this morning at around 8.15am in Dublin 2. Was the Three Rock transmission turned off? I have been able to listen to it yesterday and most mornings last week. I'm based in Dublin 2 using a Sony DAB XDRS1.

I hope the DAB trial is transformed into a proper service as I enjoy listening to WRN and Lyric and Today FM via DAB and am disappointed I can't in the evenings.

I have listened to DAB in the UK for quite a few years and particulary like to listen to BBC World Service, Oneword and some of the music stations such as Real Radio and Captial Disney: none of which are available in analog. I understand the discussions about the quality of DAB but I don't think bit rates/MP2/MP3/AAC show the full picture. In the UK I was able to compare the sound from my DAB Sony Tuner (ST-D777ES) with the sound of the same station on Freeview from the Panasonic Freeview box. In both cases, linked to the same high-end amp and speakers. The sound was far superior from the Sony even though, I believe the station from the Freeview was at a higher bit rate. Of course the Sony Tuner was quite a bit more expensive and is a dedicated to sound rather than sound and pictures but this shows that what happens to the digital signal is important as well. The sound was also better on the DAB tuner than from a Sanyo Worldspace tuner.

I haven't compared the DAB signal with FM in the home but on a handheld DAB receiver in Manchester the DAB signal almost always sounds better because there is less interference. It used to be the case that you couldn't listen to DAB on the train except near the larger cities but it improving all the time.

Although I'm a big fan of DAB, maybe Ireland is better waiting before going ahead if many countries are doing the same? How does the American In Band system compare in quality terms?

Has anyone heard anymore about when the combined DAB/DRM radios will become available? I think I read that they should be around at the end of last year, but haven't been able to find anywhere online selling them. I particularly liked the look of the Starwaves one as shown 2/3rds of the way down this page:
http://www.ahrt.hu/en/services/DE4670D957E6474FBA779D3FF881742E.php

DMC

Hi waiguoren, welcome along.
It seems Three Rock was quiet all day. I have to say I'm enjoying WRN too.... radio is one thing I dont use a lot of on satellite.

Hissing Sideban

waiguoren wrote:

Has anyone heard anymore about when the combined DAB/DRM radios will become available? I think I read that they should be around at the end of last year, but haven't been able to find anywhere online selling them. I particularly liked the look of the Starwaves one as shown 2/3rds of the way down this page:
http://www.ahrt.hu/en/services/DE4670D957E6474FBA779D3FF881742E.php

I saw several working models at IBC in Amsterdam last year, but obviously there must be production difficulties - if they could have got them out by Christmas as promised, they would have for sales reasons alone. Now , I wouldn't be surprised if it at least the summer before they are available to buy. I want one though, at present I have a Ten Tec with 12kHz I.F. out which I can feed to my PC and demodulate using either Dream (works best with weaker / noisier sigs, but no SBR) or the Merlin Software AAC SBR, so best quality)

SimonMaher

Because Im such a nerd, my Accoustic Solutions portal 2 radio arrived today. Lovely receiver too, good performance on FM and DAB. Good sound too. 3 rock coming through very well with the smallest bit of antenna selected. Will take it on the road at the weekend and see what happens!

Pete

byrnefm

Three Rock is on this morning, so I tested it along Anglesea Road, as far as Ballsbridge Motors on Shelbourne Road. No break-up at all, though I was surprised that the signal error went as high as 14 at one point and was regularly between 4 and 10, considering how close to Three Rock we are here (even with buildings factored in).

Interesting program on WRN about Flexcrete - ash mixed with cement or something like that, that many of the new Navajo buildings by the four corner states in the US are being built with. I'll miss this station when it goes!

L1011

WRN is FTA on Astra 2, so you'll still be able to get it if you want it. Nowhere near as convenient as a portable DAB, but similar enough to a table radio.

"WRN English Europe 11389 V 27500-2/3"

byrnefm

No satellite dish at my house, unfortunately (I'm renting) - however, I'm sure I'll find it on shortwave, too. Didn't know it was on satellite, though - cheers!

DMC

Back at home yesterday, Three Rock was definately stronger here indoors than Clermont Carn was last week, which is excellent news. About 60% outdoors, and useable indoors.

Still here today, and my guess is that Three Rock is off air today?

byrnefm

Three Rock was on the air yesterday all day, AFAIK - it certainly was at 8:15pm last night, anyway and is still on air at the moment.

Question - on the following Radio Engineering website in the UK:
http://radioengnews.blogspot.com/

It mentions of several DAB channels for each region (I'd say Dublin and Donegal were mixed up) and I contacted the blog owner about it, as I've never seen channel 11 mentioned for DAB here before. He said that he came across it on some EU website - is RTÉ planning on acquiring the channels listed on this webpage at the RRC this year?

lawhec

It might well be that these block 11 assignments were already there, it is that while TV bradcasts on Channel I continue from Truskmore and Mt.Leinster, they're unusable for the time being.

Edit - some details here (very technical!) - http://www.itu.int/ITU-R/conferences/rrc/rrc-04/intersession/workshops/damaskus/docs/Exercise/ITU_7_Digiital_Exercise.pdf

waiguoren

I was able to pick up the 6 stations at the weekend no problem from my Sony DAB radio. However, it was a bit hit and miss from my handheld DAB radio walking around Dublin 1&2 - sometimes I just got no sound out at all without any explanation as to why. It is the trinlock srpocket dab which is also sold under another name by Richer Sounds. It works fine in Manchester city centre though, so it looks like they need to do a bit more work on the DAB network here.

Has anyone got a WIFI radio such as this one:
http://www.reciva.com/news/article.asp?ItemID=45

WRN is also available on Worldspace (I can't remember if WRN is one of the few free channels or not), but I think it's better to wait until DRM is available as I'm sure WRN will be available there.

Mayo Exile

It was mentioned further up the thread that it was not worth buying a DAB set just to listen to RTE's test broadcasts. So I am enquiring as to whether UK DAB signals can be picked up indoors in Dundalk town or whether you would need an external antenna or can they be received at all?

White Horse

Mayo Exile wrote:

It was mentioned further up the thread that it was not worth buying a DAB set just to listen to RTE's test broadcasts. So I am enquiring as to whether UK DAB signals can be picked up indoors in Dundalk town or whether you would need an external antenna or can they be received at all?

I am able to pick up BBC digital radio via a loft aerial 10 miles south of Dundalk. Until RTE started transmission, I had a 100% signal. Since RTE started transmission, I have less than 50%. It's still listenable though, with no breaking up.

I'd guess you'd need a loft aerial in Dundalk. To get a good reception via a telescopic area, you'd need to be in the west of the county and well above sea level.

If you purchase, make sure you buy a dab radio that works well in fringe areas. I have two radios and the ability of each to pick up a weak signal is very different.

DMC

Which of the two pick up the weak signal better, WH? The Arcam DT81 or the Roberts RD1?

White Horse

DMC wrote:

Which of the two pick up the weak signal better, WH? The Arcam DT81 or the Roberts RD1?

The Arcam DT81 picks up the weak signal much better. It also has a superb DAC. That's what you get for £500, I suppose.

The RD1 is great for recording onto SD cards and transferring to my IPOD, but requires a stronger signal than the Arcam.

Mayo Exile

There's a rooftop uhf directional aerial getting Group A tv signals from Divis. Would this pick up DAB signals as well, even though its not the right aerial for the job?

DMC

White Horse wrote:

The Arcam DT81 picks up the weak signal much better. It also has a superb DAC. That's what you get for £500, I suppose.

The RD1 is great for recording onto SD cards and transferring to my IPOD, but requires a stronger signal than the Arcam.

Heh, guessed as much.

Mayo Exile

There's a rooftop uhf directional aerial getting Group A tv signals from Divis. Would this pick up DAB signals as well, even though its not the right aerial for the job?

Would this work?

lawhec

Mayo Exile wrote:

Would this work?

Pretty much only in the sense of acting like a random piece of metal as...

(A) the frequencies for DAB are well out of band for the TV aerial in question.
(B) the aerial will be horizontally polarised while DAB transmissions are vertical.

It would be no harm trying I suppose but don't expect miracles.

Mayo Exile

Thanks for that NC. Much like a lightning conductor is a piece of metal I suppose...!!!! Its been mentioned in other threads that if you can get Freeview, DAB reception is possible. I get solid enough reception on BBC4, Channel Five, as well as patchy reception on BBC1, 2, UTV, Ch. 4 etc. So I was thinking DAB reception could be possible.....

lawhec

Mayo Exile wrote:

Thanks for that NC. Much like a lightning conductor is a piece of metal I suppose...!!!! Its been mentioned in other threads that if you can get Freeview, DAB reception is possible. I get solid enough reception on BBC4, Channel Five, as well as patchy reception on BBC1, 2, UTV, Ch. 4 etc. So I was thinking DAB reception could be possible.....

That's a rather dangerous assumption to make.

For example in Strabane it's rather difficult to receive Freeview on DTT, but DAB radio is perfectly possible.

Mayo Exile

That's a rather dangerous assumption to make.

Apologies. A lightning conductor is a potentially important piece of equipment!

(A) the frequencies for DAB are well out of band for the TV aerial in question.
(B) the aerial will be horizontally polarised while DAB transmissions are vertical.

What are the frequencies in Mhz DAB is broadcast on? What type of external aerial would you need?

Hissing Sideban

DAB is on Band III, typically around 200 MHz

What would work reasonably well is an RTE tv aerial - ideally one that is not too narrowband, like the skeleton slot design ( a horizontal rectangle, the coax connected across the middle and with two vertical reflectors behind, each joined with a short piece of aluminium to the shorter sides of the rectangle) or the log periodic - (looks sort of like a very tapered yagi,) - both should be available from local TV shops, (in non UHF areas of course)

DMC

Mayo Exile wrote:

What are the frequencies in Mhz DAB is broadcast on? What type of external aerial would you need?

RTÉ are currently using 12C, which is 227.360 MHz
12A, the other frequency alotted for Ireland, is 223.936 MHz.

In the North, the BBC mux is on 12B, 225.648 MHz, while Score is on 12D, 229.072 MHz

Mayo Exile

RTÉ are currently using 12C, which is 227.360 MHz
12A, the other frequency alotted for Ireland, is 223.936 MHz.

In the North, the BBC mux is on 12B, 225.648 MHz, while Score is on 12D, 229.072 MHz

These are VHF Band III, channel J frequencies aren't they? I have an old VHF RTE aerial used when the local Castlebar RTE relay broadcast in VHF in pre-TG4 days. This would work wouldn't it? Does anybody know what VHF frequency this relay used then?

DMC

Yep, Channel J alright. I've no idea what Castlebar VHF relay was on.

lawhec

DMC wrote:

Yep, Channel J alright. I've no idea what Castlebar VHF relay was on.

The old Castlebar relay, when on VHF used VHF Band III channels D and F.

Mayo Exile

The old Castlebar relay, when on VHF used VHF Band III channels D and F.

Thanks for that NC. Would my VHF aerial work, despite the DAB frequencies being J, even though its probably meant for D and F?

satgirl

Was in Peats, Parnell Street today.

They had a Harmon Karden tuner on display picking up Lyric on DAB @ 192kbits.

byrnefm

That's a good way of them [Peats] causing trouble for themselves in three months, after the signal's switched off "Hey, this worked yesterday!"

byrnefm

Tried out the DAB portable up to the airport on Monday night (Three Rock was on) - reception was clear for the most part on the Aircoach except around Parnell St and some streets nearby (including one or two spots near the airport on the M1), where reception level dropped so low (3 '>') that burbling happened for a moment or two. Apart from that, it was good. Even so, I'd have hoped for non-interrupted reception all the way, though maybe I'm asking for too much

It was kind of funny listening to WRN on the way at around 7pm - programming changed from Radio Polonia to ... RTÉ Radio 1 news! There was definitely a gap in time between Radio 1 and that on WRN by a few minutes (though that, of course, had nothing to do with it being on DAB).

lawhec

LIFT ALERT!!!
Digital 1 is coming in for myself full whack on 12A and bubbly on 11D. Score Ayr (11B) is also coming in above threshold.

Disappointingly, still no sign of the RTÉ DAB test on 12C despite better reception on FM from Celrmont carn than normal and most of the FM stations from Three Rock coming well in

stylers

Howye All,

good bit of a lift on tonight, should be good for next 2 days or so. no sign of the BBC or score MUX's down here in westmeath yet though...

Owen.

http://home.cogeco.ca/~dxinfo/tropo_nwe.html

Theres high pressure meandering about the place and its likely to be around for a while so you should see it affecting radio signals in a good way from time to time.

watty

Yep on Monday all day a VHF 2 way radio in Co. Limerick was working with a Cornish repeater. Less than 2W TX and with 10dB receive attenuator. Absolutely perfect audio for at least 4 hours, with poorer signal in afternoon.

It was also operating with a Belfast (Hollywood hills) repeater. It *IS* connected to an aerial 30m (90ft) up a mast on a fairly serious hill.

In November it was on test here and linking to Dundee.

It is part of a larger Irish VHF/UHF repeater network and used to link a VHF repeater in N. Tipp with a UHF repeater in Mid Co. Limerick.

Sunday and last Monday week was good too. but today it has shifted. Spanish stations heard today via Mullaganish VHF repeater, or possibly a Spanish repeater heard direct to Limerick City. Around 1991 I picked up Spanish TV near Sth Cir Rd in Limerick on a portable TV with whip aerial on VHF.

watty

If you have a scanner and are in Co. Limerick, bits of Sth. Clare and SW / W Tipp and have a UHF FM scanner

Listen 433.125MHz.

It is retransmitting a VHF signal received in Co. Limerick. Yesturday Belfast and Cornwall. Today it has weak signal from Dundee in Scotland, occasionally Belfast. The VHF receiver has a 10dB attenuator on it

Should be really good today for DX DAB.

deaglan169

hi ive posted here before but for the last month i have been trying to receive the dab transmissions from claremount cairn but with no success can anyone explain, i have a good signal on my 2m radio from the dundalk repeater which i beleive is located on the same site or if not very close i have full receive on divis and score mux's

declan

watty

Clarmont Cairn is RTE site in County Louth. You can get 2m from it now near Red Cow/Naas on N7. I can't see why it would have DAB other than tests, and I thought all the tests at the moment where at Three Rock in Dublin Hills near Dundrum. BTW during the "lift" or tropo ducting last weekend the 2m link rig (1.5W) on the Limeirck 70cm was heard in Wales on a HT with 4" rubber duck.

White Horse

deaglan169 wrote:

hi ive posted here before but for the last month i have been trying to receive the dab transmissions from claremount cairn but with no success can anyone explain, i have a good signal on my 2m radio from the dundalk repeater which i beleive is located on the same site or if not very close i have full receive on divis and score mux's

declan

Hard to explain, I live 10 miles south of Dundalk and the signal from RTE dab signal is very strong. So strong that it partially blocks out the BBC signal from Divis.

However, I receive the signal via a loft aerial.

byrnefm

I know telephone details for RTÉ have been posted on this thread for reception reports - is there an email address available for such also? I notice that RTÉ's page on digital broadcasting (http://www.rte.ie/radio/dab.html) that it mentions of RTÉ's DAB trial and that initial results are 'very encouraging'. I want to email them a reception report but don't know where to send it to, if such an email address exists for them!

Conor S

The address you need is bernie.pope@rte.ie

LOL the DAB trial is nearly over and they still have the wrong time broadcasting........meaning I couldnt listen as much as I would have liked.
Has anybody the actual date that the trial is due to end on?

byrnefm

Conor S wrote:

The address you need is bernie.pope@rte.ie

LOL the DAB trial is nearly over and they still have the wrong time broadcasting........meaning I couldnt listen as much as I would have liked.
Has anybody the actual date that the trial is due to end on?

Cheers, Conor!

Haven't seen any concrete info as to when the trial ends, apart from that it's stated as being for three months from January 1.

Curious - why could you not listen as much as you'd have liked? (I don't understand your comment about the time, unless you mean the time reported by the multiplex on your DAB receiver, which is indeed out by about four years!).

Conor S

My DAB radio ('the bug') takes the time (or at least it did until yesterdays software upgrade) from the multiplex.I couldnt listen to RTE mux because it meant the time would be wrong and I couldnt set it as an alarm for Kiss100 in the morning.
Oh yeah and the fact that its all crap except today fm and WRN might have had something to do with it aswell.
LOL
Conor

waiguoren

When I tuned into WRN at around 9.30pm yesterday, I found I was listening to 'RTE Radio 1 Extra' instead, with what sounded like the Brat Pack Tribute Concert. The display still showed WRN. An hour later when I tuned into the station again, WRN had returned with NPR. I must say I would prefer to receive WRN instead of RTE Radio 1 Extra as I missed China Radio International with its news features and daily mandarin lesson.

In Pete's shop on Parnell Street there's a sign saying that a full range of DAB receivers will available from September. They had the Tivoli Model DAB already been displayed available for 299 euros.

watty

WRN sometimes is actually RTE. Perhaps that's what you heard. Did you check WRN schedule?