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RTE Long Wave 252 reprieve ? |
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#101 |
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Join Date: Jan 2015
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Could they put on freeview in the uk or is that expensive?
Ideally I'd say Free view plus local DAB in London and Northern Ireland. |
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#102 |
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Join Date: Dec 2009
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Could they put on freeview in the uk or is that expensive?
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#103 |
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I would not have expected it to be cheap and it has to be remembered that most of the Freeview relay stations only have Freeview Lite which only has a limited number of radio stations and in Scotland some are dropped in the evening when BBC Alba is on. So to get national coverage on Freeview a BBC station would have to be dropped which is not going to happen.
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#104 |
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Join Date: Jun 2014
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That would be my second choice if national DAB was too expensive.
Ideally I'd say Free view plus local DAB in London and Northern Ireland. |
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#105 |
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Join Date: May 2013
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Uk dab and freeview would cost more than lw, one must remember that the reason for turning off lw is to save money. Reading between the lines, i think rte have in mind to supply elderly people with help to get listening via a table or freesat etc
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#106 |
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sorry if this is a stupid question but would a move to MW on a frequency or 2 help save money and keep the service running?
maybe a couple of tx in the uk or a high powered one from the coast of ireland if they got anything like that still around? |
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#107 |
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Join Date: Sep 2005
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sorry if this is a stupid question but would a move to MW on a frequency or 2 help save money and keep the service running?
maybe a couple of tx in the uk or a high powered one from the coast of ireland if they got anything like that still around? Using a higher frequency would just reduce the daytime coverage. This rather optimistic map shows that 100kW wouldn't go very far into the UK mainland, and fillers are needed in Londonderry and Enniskillen. If they can't afford the electricity to operate one existing LW transmitter, they certainly wouldn't be able to afford the capital expenditure to build a couple of MW powerhouses let alone run them. And they'd never be licensed in the UK. If they want to reach most of the UK from the RoI there's only one answer, to restore high power and to switch to a clear LW channel (261kHz). |
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#108 |
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Join Date: Jan 2015
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I would not have expected it to be cheap and it has to be remembered that most of the Freeview relay stations only have Freeview Lite which only has a limited number of radio stations and in Scotland some are dropped in the evening when BBC Alba is on. So to get national coverage on Freeview a BBC station would have to be dropped which is not going to happen.
Personally I think we should be getting full Freeview onto as many transmitters as possible. |
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#109 |
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Join Date: Apr 2011
Location: Future EU Scottish Republic
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sorry if this is a stupid question but would a move to MW on a frequency or 2 help save money and keep the service running?
maybe a couple of tx in the uk or a high powered one from the coast of ireland if they got anything like that still around? |
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#110 |
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Join Date: Dec 2009
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Uk dab and freeview would cost more than lw, one must remember that the reason for turning off lw is to save money. Reading between the lines, i think rte have in mind to supply elderly people with help to get listening via a table or freesat etc
It does not have to be anything too complicated so could be done cheaply. |
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#111 |
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Join Date: Feb 2006
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Absolutely not !
Using a higher frequency would just reduce the daytime coverage. This rather optimistic map shows that 100kW wouldn't go very far into the UK mainland, and fillers are needed in Londonderry and Enniskillen. If they can't afford the electricity to operate one existing LW transmitter, they certainly wouldn't be able to afford the capital expenditure to build a couple of MW powerhouses let alone run them. And they'd never be licensed in the UK. If they want to reach most of the UK from the RoI there's only one answer, to restore high power and to switch to a clear LW channel (261kHz). i did think that would probably be the case. and i agree that the only way does look like a high power 261. i wonder how far a high powered 261 would get and what power they would be allowed to go at on there if allowed? what about 279? closest station on this is TR1 from Turkmenistan? or 180? no station is on that i think |
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#112 |
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Join Date: Jan 2015
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If the Isle of Man will release the frequency, sure.
But it is missing the point that RTE are looking to get out of the longwave game, not find a new frequency! |
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#113 |
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Join Date: May 2004
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I somehow missed this article by Noreen Bowden in the Irish Times a couple of months back. Not sure how accurate her information is that it would only "...require a small amount of diplomacy to negotiate the switch with international governing bodies, and a relatively minor technical adjustment that could be done overnight..." in order to secure 261 kHz.
For a start, there are thousands of notch filters installed on phone lines for miles around Summerhill, before even getting to the ATU or TX final stages. However, it's fascinating the reference to the sudden increase in interference from Algeria being down to their turning up the wick in order to reach their own diaspora in France; they've renewed their TX, did the power increase at the same time? I'm not familiar with the telephone line filters installed, but I can't imagine the notch would be so tight as to be ineffective on the adjacent 261kHz? A filter with a very tight notch could easily drift off frequency caused by varying characteristics of the phone line, so I doubt these filters actually have a very tight notch. Even if these phone line filters were a few dBs less effective on 261, its counterbalanced by the lesser power nowadays compared to the Atlantic 252 days. Even if there is just one more year left in RTE's LW service, its surely worthwhile to try gain international agreement for temporary permission to move to 261kHz at the current power, under the understanding that if Germany etc were to reactivate 261 that RTE would have to revert back to 252 again (but how llikely is the latter to happen) |
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#114 |
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I'm not familiar with the telephone line filters installed, but I can't imagine the notch would be so tight as to be ineffective on the adjacent 261kHz?...Even if there is just one more year left in RTE's LW service, its surely worthwhile to try gain international agreement for temporary permission to move to 261kHz at the current power, under the understanding that if Germany etc were to reactivate 261 that RTE would have to revert back to 252 again (but how llikely is the latter to happen)
A move to 261kHz would be worthwhile at least seeking, as there is zero chance of Germany reactivating that frequency given that Federal and local government there has decreed that there should be no more "wasteful" transmissions via AM. I was just pointing out that a frequency move was nothing like as simple as rocking up at Clarkstown and twiddling a dial, as the person who wrote the linked article seems to think. |
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#115 |
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Join Date: May 2004
Location: southern Ireland
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or 180? no station is on that i think
279 would be feasible (now totally clear at night in Europe), however 261 is preferable for a number of reasons. For a start some dial tuned receivers don't go up as far as 279 |
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#116 |
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Join Date: May 2004
Location: southern Ireland
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Even with a fairly ordinary Q factor of 100 or so, an L-C tank circuit at 252 kHz only has useful rejection of around 2.5kHz, so it wouldn't be much use on 261. The filters are in-line with the phone receiver after any ADSL microfilter, to counteract AM rectified and audible through the earpiece, so you could probably just issue new ones for 261kHz to all in the area who required one.
. I would have thought that low-pass filters would have generally been installed rather than notch filters on telephones, so would be immune to a frequency change upwards. What type of telephone filters get installed (and to what extent are filters needed) around Droitwich, where there is more than one frequency to worry about? |
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#117 |
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Until RTÉ gets interested in and eventually applies for a change of frequency this is all conjecture, but a shift to 261 kHz may just about be possible via physical alteration or replacement of the existing inductors and coils in the Antenna Tuning Building.
Even if there were widespread availability of LW radios capable of tuning 279 kHz, this would be a shift in frequency of nearly 10% so there's zero chance that the existing ATU would be able to tune that. It would be a major project to rebuild and re-commission the ATU/Antenna combination at 279 kHz. With downtime stretching into months RTÉ might as well just pack the service in anyway. |
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#118 |
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Join Date: Mar 2016
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Easiest and cheapest way to get RTE Radio 1 or 2 for that matter is to buy an old sky box off ebay with a dish and connect up to your stereo.
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#119 |
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Join Date: Mar 2016
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Surely the rejection would have to be wider than 2.5kHz to attenuate the sideband energy. Its also the case that the transmitter moved by 2kHz years ago (from 254), and I don't recall any reports of filters needing to be changed then.
I would have thought that low-pass filters would have generally been installed rather than notch filters on telephones, so would be immune to a frequency change upwards. What type of telephone filters get installed (and to what extent are filters needed) around Droitwich, where there is more than one frequency to worry about? |
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#120 |
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Join Date: Apr 2011
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Surely the rejection would have to be wider than 2.5kHz to attenuate the sideband energy. Its also the case that the transmitter moved by 2kHz years ago (from 254), and I don't recall any reports of filters needing to be changed then.
I would have thought that low-pass filters would have generally been installed rather than notch filters on telephones, so would be immune to a frequency change upwards. What type of telephone filters get installed (and to what extent are filters needed) around Droitwich, where there is more than one frequency to worry about? If there were more than one frequency such as at Droitwich and other mainland Britain sites then yes, you would just have to use a low-pass filter and hope for the best. However, unless it's multipole i.e. quite a few components and therefore quite expensive, then the rejection obtained over the two decades 3-300 kHz will be around 20 dB poorer than even the simplest notch filter with a decent Q factor coil. |
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#121 |
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Join Date: Nov 2005
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If the Isle of Man will release the frequency, sure.
But it is missing the point that RTE are looking to get out of the longwave game, not find a new frequency! Regards |
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#122 |
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Join Date: Feb 2011
Location: Just passin' through
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Until RTÉ gets interested in and eventually applies for a change of frequency this is all conjecture, but a shift to 261 kHz may just about be possible via physical alteration or replacement of the existing inductors and coils in the Antenna Tuning Building.
Even if there were widespread availability of LW radios capable of tuning 279 kHz, this would be a shift in frequency of nearly 10% so there's zero chance that the existing ATU would be able to tune that. It would be a major project to rebuild and re-commission the ATU/Antenna combination at 279 kHz. With downtime stretching into months RTÉ might as well just pack the service in anyway. The ATU, or matching unit, is to match the base impedance of the antenna to the transmitter/feedline. It doesn't actually tune the aerial. Without knowing the base impedance, it's virtually impossible say whether it will "tune" the antenna to 279 but, given that these units are variable (they have to be), there's a good chance that it will. |
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#123 |
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No, knock out the carrier frequency and that's pretty much it. The stray audio arises from old-fashioned envelope detection at spurious non-linear junctions, so no envelope = no detection. For normal speech frequencies, as carried by RTÉ 1 Extra, most of the energy is concentrated around +/- 2 kHz. So a notch on 252 kHz is going to leave pretty much just higher sideband energy which, if it's audible at all, will just sound like periodic background noise and won't be obtrusive.
If there were more than one frequency such as at Droitwich and other mainland Britain sites then yes, you would just have to use a low-pass filter and hope for the best. However, unless it's multipole i.e. quite a few components and therefore quite expensive, then the rejection obtained over the two decades 3-300 kHz will be around 20 dB poorer than even the simplest notch filter with a decent Q factor coil. They usually come in different ranges. e.g. 500 KHz to 1.5 MHz. Chances are that the filters used there are good for the whole LW band. Incidentally, I've used the ASDL filters with reasonable good success for eliminating RFI on my phone. |
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#124 |
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Join Date: Feb 2011
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Even if there were widespread availability of LW radios capable of tuning 279 kHz, this would be a shift in frequency of nearly 10% so there's zero chance that the existing ATU would be able to tune that. It would be a major project to rebuild and re-commission the ATU/Antenna combination at 279 kHz. With downtime stretching into months RTÉ might as well just pack the service in anyway.
If the Clarkstown mast is 248 mtrs (the only figure I can find), it will be closer to 75 degrees and will have a base resistance in the low/mid 20's on 252 KHz. The same mast on 279 is about 83 degrees and a resistance of around 30 Ohms so easier to match to 50 Ohms using the same network. This are quick, back of an envelope calculations, so won't be 100% accurate and I'm open to correction. |
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#125 |
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Join Date: May 2013
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I believe that RTE have said that the mast insulators/stay wires will need to be replaced before the end of the decade ?
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