Is Kippure not transmitting on CH61?

keithoh

Has Kippure stopped transmitting on CH61? I was getting no signal on my PZ81B last night. In the tuning menu I could see that CH54 was at full strength, but I didn't want to do a rescan as I'm not sure whether RTENL are transmitting with the setting that the PZ81B's don't understand.

yup 61 is off as of now-just checked.

54 is 3 rock I presume ?
Thats on,I have 40% strength and 10% quality on that one.
We have weak 3 rock analogue here west of Arklow believe it or not [also get good 98fm but only here-drive about and you lose it] and thats despite all the wicklow mountains being in the way!

They are probably working on the tx-I'd expect it back on by the days end.
They did this with mt leinster during the week also.

keithoh

Thanks Black Briar

Thoie

Mine seems to be half back - in that I'm getting about half the screen, but not much more. I thought with digital you either received it perfectly, or not at all - are they likely to be running half a test?:rolleyes:

SRB

Kippure originally came on using Ch61, with Three Rock on 54, they switched last year, with Kippure using 54 and Three Rock 61. Since late last year I've been watching Kippure on 54, with Three Rock on 61 during lift conditions. There was talk of an SFN testing on both channels.

keithoh

Does anyone know if it's safe to rescan with the PZ81B at present, or are RTENL broadcasting with the setting that wont store the channels on the PZ81B?

pa990

is it possible to do a scan without deleting what u already have ?

SRB

If it's any help, two of the boxes I have, which wouldn't store the channels last year (when the descriptor first changed) are both storing them fine - just re-scanned them. (Ch 54)

Are you telling me that the ch61 that I've been picking up all along down in Arklow was actually 3 rock?

keithoh

SRB wrote: »

If it's any help, two of the boxes I have, which wouldn't store the channels last year (when the descriptor first changed) are both storing them fine - just re-scanned them. (Ch 54)

Thanks SRB, I'll try a rescan later today

SRB

Deleted User wrote: »

Are you telling me that the ch61 that I've been picking up all along down in Arklow was actually 3 rock?

When Three Rock came on it was orginally on 54, also appeared on 61 towards the end of last year. Kippure was on 61 but moved to 54. Now, if they were running an SFN, Three Rock was would still have been running on 54.
The signal levels and direction of the signal I was receiving on 61 until the end of last week would point to 61 coming from Three Rock.
I'm in Portaferry Co. Down.

So no one except RTENL knows then for sure?

Both tx's are about the same area just one is a few miles further inland than the other.

I definitely should not in my opinion be receiving dtt from 3rock amp less.
I should be able to pick it up from kippure though.I've great VHF tv from there and vhf radio services and better uhf than I do for 3 rock.

SRB

Someone on here mentioned they were running an SFN on 54 from Three Rock and Kippure, so I take it that is/was on air. As for 61, I can only go on the signal levels where I am and it was consistant with the power from Three Rock. It's possible they had another TX on Kippure with power restrictions Northwards, but that would be a bit strange given the signal on 54 from the same site...
Are you getting anything on 54 at the moment ?
I suppose an e-mail to RTE NL would solve the mystery, lol.

fat-tony

Three Rock has been transmitting on CH54 and Kippure on CH61. At the moment(11.50) Three Rock is on and Kippure is off.

SRB

Kippure was/is on 54 too Tony. It's been there since the end of last year when all it's muxes were active for an afternoon.

I'm beginning to think theres confusion here.
ch61 up to the other day must have been kippure.

If kippure and 3rock were both on 54 at the same time,that would be absolutely pointless.
Nothing would be received as they are only a couple of miles apart and both are in line of sight through most of Dublin and beyond to the north of Dublin.

The Cush

Deleted User wrote: »

If kippure and 3rock were both on 54 at the same time,that would be absolutely pointless.
Nothing would be received as they are only a couple of miles apart and both are in line of sight through most of Dublin and beyond to the north of Dublin.

They will be operated as a Single Frequency Network (SFN). DAB operates this way.

SRB

Yup, if you remember just over a year ago, there were timing issues with the SFN, Three Rock then ran on 54, Kippure came up on 61. It moved back to 54 towards the end of last year and as far as I know was running along side Three Rock on 54. On the day Kippure moved to 54, it was on and off over the afternoon, the signal on 54 with me was as normal for Three Rock, then shot up to the same level as the signal I had been receiving on 61. 61 then dropped to the level that I would expect from Three Rock and stayed that way.
As I say, an e-mail to RTE NL would clear this up.

This appears to be supposition.

If an sfn is possible with dtt [I know that cofdm cannot cope with strong co channel-presely Vs Mt Leinster is an example] then the whole country should be on ch 39.

Where is mrdtv when we need him

Yes someone email RTEnl.

keithoh

Deleted User wrote: »

Yes someone email RTEnl.

I sent them an email today asking about Kippure and Three Rock, I'll post the reply if I get one

SRB

Deleted User wrote: »

This appears to be supposition.

If an sfn is possible with dtt [I know that cofdm cannot cope with strong co channel-presely Vs Mt Leinster is an example] then the whole country should be on ch 39.

Where is mrdtv when we need him

Yes someone email RTEnl.

Honestly, it is perfectly possible and there was one running on 54. (It may well still be running on 54 - anyone in the Three Rock area who can't "see" Kippure should be able to confirm this if they are getting a strong signal, it'll be Three Rock). An SFN is not the same as two different services on the same channel, which is the issue with Wales and Mt Leinster.

The Cush

Deleted User wrote: »

This appears to be supposition.

If an sfn is possible with dtt [I know that cofdm cannot cope with strong co channel-presely Vs Mt Leinster is an example] then the whole country should be on ch 39.

Attached is some info I think I posted previously.

In Spain the four commercial multiplexes operate as nationwide SFNs, UHF Channels 66 - 69. The national PSB mux operates as an MFN. On the Isle of Man 3 relays I believe operate as an SFN.

This was a discussion on SFNs over in the DS forum last year http://www.digitalspy.co.uk/forums/showthread.php?t=1035699

Antenna

In the Cork area, Spur Hill and Crosshaven were at one stage planned to operate on the same channels as a SFN , though that plan has gone out the window.
So too has Kippure and Three Rock in the Dublin area (a similar distance apart) with the new plan (see below) they are no longer to use the same channels.

https://us.v-cdn.net/6034073/uploads/attachments/10144/108434.pdf
Third column is Channel number

Kippure DTT is now allocated channels 29, 33, 35, 37, 55, 59, 62, 65
Three Rock DTT is allocated 23, 26, 30, 34, 54, 58, 61, 64
none are co-channel.
(attachment originally posted by The Cush)

The Cush

Antenna wrote: »

In the Cork area, Spur Hill and Crosshaven were at one stage planned to operate on the same channels as a SFN , though that plan has gone out the window.
So too has Kippure and Three Rock in the Dublin area (a similar distance apart) with the new plan (see below) they are no longer to use the same channels.

https://us.v-cdn.net/6034073/uploads/attachments/10144/108434.pdf
Third column is Channel number

Kippure DTT is now allocated channels 29, 33, 35, 37, 55, 59, 62, 65
Three Rock DTT is allocated 23, 26, 30, 34, 54, 58, 61, 64
none are co-channel.
(attachment originally posted by The Cush)

That document is the DTT plan from RRC-06 but its not written in stone. Following the conference countries can enter into bilateral agreements with other countries to amend or change an assignment. This is what happened to Three Rock/Kippure. Kippure has been assigned the same frequencies as Three Rock to become an SFN.

Since 2007 the Three Rock/Kippure SFN has been part of the Irish DTT plan, see Comreg document 07/65.

Don't know why this was done, maybe it was done because of the close proximity of the two main transmitters and to develop the expertise and knowledge in building SFNs, maybe it was done to free up these frequencies for use in relays (low power sites were not allocated frequencies at RRC-06), maybe it was done in coordination with Ofcom/Arqiva as a trade off somewhere else.

SRB

The MUX I'm sitting monitoring tonight, on CH 54, is not from Three Rock. Three Rock analogue is totally unwatchable with me this evening, hardly any trace of a signal at all (TG4). The signal on 54 has to be coming from Kippure.

lawhec

DVB-T Single Frequency Networks are in place in several countries. As The Cush points out, there is a national 4 Multiplex SFN in Spain (using frequencies E66, E67, E68 and E69). IIRC in Portugal the RTP (public) multiplex was to be a national SFN as well but I don't know if it was implemented as such.

Several countries have regional SFNs including (off the top of my head) the Netherlands, Germany, Belgium & Switzerland. In these cases there is either one main high powered transmitter with on-channel low powered filler transmitters (sometimes with opposite polarity) or they can work as mid to low powered transmitters as a cellular style network. The Digital Spy post mentioned that there is a small SFN multiplex in northern France for the TF1 Multiplex. In Australia, SBS operates a SFN multiplex in the South-East Queensland region involving IIRC seven transmitters all on-frequency. In the UK digital rollout, SFNs are being kept to some small scale areas of low-powered relays each using similar frequencies - there's one on the Isle of Man, I think there's also SFNs planned for part of the Channel Islands and in parts of southern England, but I'll need to double check.

In theory the whole of the Irish Republic could be covered by a SFN at least for a public broadcasting multiplex that didn't need to be regionalised, however it would need to be engineered in a different fashion to that for a multi-frequency network which is what RoI has planned through its allocations (as does the UK in general) not to mention that it may require some viewers to need different UHF aerials compared to their current one required for analogue broadcasts (though this is the case anyway for Mt. Leinster and Spur Hill).

Country-wide Single Frequency Networks don't lend themselves well to the current analogue VHF/UHF TV network of having several transmitters with high powers spaced quite widely apart. Even using the 8K COFDM mode with a long guard interval only gives some protection, receiving a distant transmitter from a distance greater than the guard allows adds or interferes to the signal destructively rather than constructively, not to mention a reduced data-rate available for the multiplex. As an example though not using DVB-T but DAB, the BBC National Multiplex on 12B is a UK-wide SFN, however ERP powers are limited to 10kW maximum so that the signal from each transmitter doesn't travel too far away into the coverage area of another distant transmitter broadcasting the same content to cause destructive interference and hence reduce the coverage area of distant transmitters.

There is a Javascript calculator here that allows you to configure different DVB-T parameters that translate into transmission details of data rates, guard intervals etc. for a DVB-T transmitter (there's an experimental DVB-T2 calculator there as well) that shows how different parameters set up for a DVB-T transmitter can be configured to give required data, coverage and network planning results and the trade offs required.

whizbang

CH 61 is Greystones relay i believe..
Also (a bit late!) kippure apparently is lower power to the east, on analog anyway.

mrdtv2010

SFN's are possible with DVB-T1 and DVB-T2. The maximum allowable distance between the transmitters varies between 2k and 8k DVB-T1 COFDM depending on the mode chosen, error correction used and data rate. Large area SFNs such as those used in Spain have lower data rates than that used in the UK or Ireland via DVB-T1. DVB-T2 uses 32k COFDM and can have much larger SFNs with much bigger distances. (This is one of the reasons why it was developed.) In SFNs the data transmitted is identical and signals add constructively whereas in the case of uncorrelated sources of roughly equal signal strength transmitting different data you get destructive interference and no pictures as is the case with Preseli COM muxes and Mount Leinster.
I have been away, but I have noticed, that as expected Irish commercial DTT has again fallen by the wayside. For the nth time. When are they going to change the regulatory structure and business model?

You can find out all about SFNs by googling the technical literature.There are too many parameters to discuss in an Internet post!

SRB

SRB wrote: »

The MUX I'm sitting monitoring tonight, on CH 54, is not from Three Rock. Three Rock analogue is totally unwatchable with me this evening, hardly any trace of a signal at all (TG4). The signal on 54 has to be coming from Kippure.

not a good guide.
I've bad kippure uhf analogue here[west of Arklow] on a grid thats pointed to mt leinster .
I could only ever see tv3 actually.
No tg4.
VHF on the other hand from there is perfect.

Up untill the other day I had good dtt on ch61 which I always took to be kippure.
I've nothing today on either 61 or 54.

SRB

Deleted User wrote: »

not a good guide.
I've bad kippure uhf analogue here[west of Arklow] on a grid thats pointed to mt leinster .
I could only ever see tv3 actually.
No tg4.
VHF on the other hand from there is perfect.

Up untill the other day I had good dtt on ch61 which I always took to be kippure.
I've nothing today on either 61 or 54.

Actually it is, if you've a steady enough but weakish UHF analogue, you can be sure you'll have a steady signal on DTT.
VHF reception is very, very different.
I've OK UHF and analogue VHF from Kippure (apart from TG4 which is wiped by co-channel from Belfast), Three Rock (where I am) is very much weather dependant and the DTT, even going back to the MPEG 2 trial from Three Rock, is exactly the same. Incidently, this afternoon, the signal I'm getting on 54 is the same level I'd expect from Three Rock, so I take it Kippure is off altogether.
There was a new caption on the RTENL testcard yesterday evening - it was in Irish though, so no idea if it was pointing to an outage.

The Cush

SRB wrote: »

There was a new caption on the RTENL testcard yesterday evening - it was in Irish though, so no idea if it was pointing to an outage.

Tarchur Digiteach (Digital Transmission). Back to Digiteach (Digital) only today.

Yes kippure ch 61 is definitely off.
It's not available here on any other channel at the moment either

SRB

Kippure is back up on 54.

Thats not kippure as I have nothing on 54 here.

SRB

Have you a grouped UHF aerial pointed at Kippure ? - what happens if you scan ch 54 ?
There is no way the MUX I've been receiving the last few months has been coming from Three Rock, it's been too consistant and too stable, while the MUX on 61 wasn't.

Peddyr

SRB wrote: »

Have you a grouped UHF aerial pointed at Kippure ? - what happens if you scan ch 54 ?
There is no way the MUX I've been receiving the last few months has been coming from Three Rock, it's been too consistant and too stable, while the MUX on 61 wasn't.

Three Rock = 54
Kippure = 61 (currently off air)

SRB

SRB wrote: »

Have you a grouped UHF aerial pointed at Kippure ? - what happens if you scan ch 54 ?
There is no way the MUX I've been receiving the last few months has been coming from Three Rock, it's been too consistant and too stable, while the MUX on 61 wasn't.

I don't but I've checked with people that have and they now only have mt leinster which is coming in on the back of their arfon aerial.

SRB

Ok, borrowed meter, compass and took laptop up to the roof. If I set the aerial at what should be the exact direction of Three Rock, I get a (just) lockable b/w analogue TG4 picture and the DTT signal drops off. (Down from 69% to 46%). If I move the aerial back to where the Kippure analogue signal peaks, the DTT goes back up. This really doesn't make sense if Kippure DTT is off. Also the analogue UHF signal from Three Rock isn't steady, it fluctuates wildly - especially when the ferry is crossing the lough in front of me - the DTT signal is steady. Might drop RTENL an e-mail myself.

Thats an awfull lot of trouble you've went to in the space of an hour...


Depends on where you are I suppose.
Remember Kippure and 3 rock are pretty much parallel.

Even if you are north of 3 rock,you are going to get signal pointing south as theres no mountains in the way.
If you are East or southeast the difference is going to be even less.

If you are pointing across a lough,is that carlingford lough? that far north?
If you are in Dublin,even North Dublin,you should see both transmitters and to be honest,there won't be a whole lot of difference in that case in signal level if using a roof aerial that can see both [when both are on]..They are after all only a few miles apart.

fat-tony

whizbang wrote: »

CH 61 is Greystones relay i believe..
Also (a bit late!) kippure apparently is lower power to the east, on analog anyway.

Greystones relay is on CH52. Was never allocated CH61. I'm less than 2k from it and it is my main source of DTT. Kippure is west of me and Three Rock is north of me.

Kippure and Three Rock were both allocated the same muxes on 54, 58, 61 and 64 which was presumably the SFN referred to. There may have been a time when Kippure and Three Rock were on the same channel(s), but for months now, Kippure has been on CH61 only and Three Rock has been on Ch54 only. I'm sure this could/might change in the future, but SRB would have been receiving his CH61 from Kippure and CH54 from Three Rock. I don't know why there is an anomaly in SRB's reception of analogue and digital from Three Rock

whizbang

Sorry Guys, too much sleeping medicine..
I had assumed that, since i took away the Greystones aerial i seem to loose ch 61 about the same time. The only tv that i can get at in the evenings doesnt show any info at all, and its only mpeg2.
I never did get anything from 3-Rock, only Kippure, but only Greystones is there now, nada 54, 61.

slegs

Peddyr wrote: »

Three Rock = 54
Kippure = 61 (currently off air)

Kippure is definitely currently broadcasting on ch 54.

I am in Kildare Town and cannot receive 3 rock under any circumstances and ch 54 is coming through loud and clear.

shinobi

I was only able to pick up Channel 61 from Kippure up to recently. Since loosing this & rescanning I've been receiving the stations both on Channel 39 (618 MHz) & Channel 42 (642 MHz) although the strength is about half of what I was getting on Kippure but I wasn't receiving these channels at all. I'm in North kildare & wasn't able to receive DTT till Kippure started testing early last year.

slegs

slegs wrote: »

Kippure is definitely currently broadcasting on ch 54.

I am in Kildare Town and cannot receive 3 rock under any circumstances and ch 54 is coming through loud and clear.

Most of wicklow it seems has lost dtt from kippure 61 and Dublin and kildare town has it as strong as ever on 54 but it's not in north kildare [according to shinobi] in sight of kippure and out of sight of 3 rock ?

I remain obviously convinced that 54 is 3 rock.

@ shinobi 39 and 42 are mt leinster.

Peddyr

slegs wrote: »

Kippure is definitely currently broadcasting on ch 54.

I am in Kildare Town and cannot receive 3 rock under any circumstances and ch 54 is coming through loud and clear.

Hi Slegs,

When did these txs swap frequencies and do you have a link to a site that confirms this? Three Rock has always been stronger to my location than Kippure and was 'on-line' on ch54 before Kippure started last year on ch61. If they have swapped which is being suggested then surely if Kippure is now on ch54 then it would be weaker than TR on ch61 as has always been the case, but I'm still getting ch54 a lot stronger than ch61 (until 61 disappeared that is) so it doesn't really convince me. I'm not wishing to be awkward or discourteous but it would be good to get official confirmation that the txs have indeed swapped.

fat-tony

As slegs is receiving DTT from Kippure on CH54 and I'm receiving DTT from Three Rock - also on CH54, the conclusion I would draw is that RTENL have re-instated the SFN at the moment:) Nothing at all on CH61 from either site.

SRB

Deleted User wrote: »

Thats an awfull lot of trouble you've went to in the space of an hour...


Depends on where you are I suppose.
Remember Kippure and 3 rock are pretty much parallel.

Even if you are north of 3 rock,you are going to get signal pointing south as theres no mountains in the way.
If you are East or southeast the difference is going to be even less.

If you are pointing across a lough,is that carlingford lough? that far north?
If you are in Dublin,even North Dublin,you should see both transmitters and to be honest,there won't be a whole lot of difference in that case in signal level if using a roof aerial that can see both [when both are on]..They are after all only a few miles apart.

I'm "Up North" in Portaferry Co, Down, almost at sea level, realistically there are only a few degrees between the two where I am, but due to co-channel (on TV3) from Newcastle Co Down, the aerial was very carefully aligned for Kippure when first installed. Something else from yesterday too - last year I noticed one of the boxes tended to rescan itself whenever there was a lift - you could tell it had done this because the channel order reversed. If it had scanned Ch61, the box put TG4 at 800, when the signal on 61 dropped again, it rescanned 54 and put RTE1 at 800. Yesterday that box had TG4 at 800 after a rescan on 54. Have rescanned it again this afternoon and it's still the same, so something was changed somewhere.

SRB

Peddyr wrote: »

Hi Slegs,

When did these txs swap frequencies and do you have a link to a site that confirms this? Three Rock has always been stronger to my location than Kippure and was 'on-line' on ch54 before Kippure started last year on ch61. If they have swapped which is being suggested then surely if Kippure is now on ch54 then it would be weaker than TR on ch61 as has always been the case, but I'm still getting ch54 a lot stronger than ch61 (until 61 disappeared that is) so it doesn't really convince me. I'm not wishing to be awkward or discourteous but it would be good to get official confirmation that the txs have indeed swapped.

Yes, Three Rock was originally on 54 and Kippure on 61, towards the end of last year, around the time the extra radio stations appeared, Kippure had a number of blank carriers running and then moved to 54, with Three Rock coming on 61. As far as I know and what I've seen over the last few days from looking at the signals very closely, there appears to be a SFN running with Kippure and Three Rock on 54. The switch was originally discussed here:
http://www.boards.ie/vbulletin/showthread.php?p=63518092#post63518092

Peddyr

fat-tony wrote: »

As slegs is receiving DTT from Kippure on CH54 and I'm receiving DTT from Three Rock - also on CH54, the conclusion I would draw is that RTENL have re-instated the SFN at the moment:) Nothing at all on CH61 from either site.

You may well have just hit the nail on the head there Fat-Tony!

fat-tony

SRB wrote: »

Yes, Three Rock was originally on 54 and Kippure on 61, towards the end of last year, around the time the extra radio stations appeared, Kippure had a number of blank carriers running and then moved to 54, with Three Rock coming on 61. As far as I know and what I've seen over the last few days from looking at the signals very closely, there appears to be a SFN running with Kippure and Three Rock on 54. The switch was originally discussed here:
http://www.boards.ie/vbulletin/showthread.php?p=63518092#post63518092

SRB - Since the testing ceased on the SFN some time back, Three Rock has been on 54 constantly, with Kippure on 61 - not the other way around. I would concur that RTENL are now testing the SFN between Kippure and Three Rock on CH54.

SRB

fat-tony wrote: »

As slegs is receiving DTT from Kippure on CH54 and I'm receiving DTT from Three Rock - also on CH54, the conclusion I would draw is that RTENL have re-instated the SFN at the moment:) Nothing at all on CH61 from either site.

Just speculation, but it's possible 61 from Three Rock was run alongside the SFN on 54 from Three Rock and Kippure to allow for tests on the impact an SFN would have on reception in the overlapping Three Rock/Kippure TX areaa, testing over, 61 would be turned off.