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RTE Long Wave 252 reprieve ? |
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#151 |
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Join Date: Apr 2011
Location: Future EU Scottish Republic
Posts: 821
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Quote:
Just to clarify, 252LW usually carries the regular RTE Radio 1 (as on FM) service not the digital radio service (on DAB/DTT/online) called 'RTE R1 Extra', EXCEPT on Sunday mornings when religious output is on LW and RTE Radio 1-Extra and also for occasional sports outputs.
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There is sideband energy beyond 2kHz, otherwise it would sound extremely muffled (notwithstanding that many modern receivers sound that way on MW/LW due to the poor design of the receivers!). Any filter would have to knock out all the sidebands as well as carrier, an AM receiver (or anything acting as an AM receiver) will receive SSB (or DSBSC) transmissions for instance as an unintelligible 'duck quack' type sound despite no carrier present.
This morning when I took a quick look at 252 to check the SDR was up and running, there was a piece of flute music which generated a beautiful pattern of switching transients. Provided you notch out roughly +/-2 kHz then these transients can only beat with each other to produce stray audio. Even for a pure tone these are only a functional of the duty cycle, switching frequency, input audio frequency and input audio amplitude, so will just sound like anharmonic noise. Quote:
I remain unconvinced that a suggested move to 261kHz (just 7kHz higher than the original frequency used - 254kHz ) would have an impact on telephone line filters.
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#152 |
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Join Date: Feb 2011
Location: Just passin' through
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RTE on 252 broadcast in AM.
Pulse AM is something different. |
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#153 |
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Join Date: Feb 2011
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Quote:
Good stuff.
True, but Clarkstown the same as pretty much all high power LW installations since the mid 80s doesn't broadcast AM, it broadcasts PulsAM. The resulting spectrum consists of the carrier, a central region of roughly +/-1kHz corresponding to the foot and summit of the carrier slew, and complex harmonics that are a function of the carrier slew rate and duty cycle, where the 'amplitude' of the audio input corresponds to the instantaneous duty cycle. Have a look at the spectrum up close in the Peterborough SDR waterfall (use the 'Zoom In' button), it's quite mesmerising. This morning when I took a quick look at 252 to check the SDR was up and running, there was a piece of flute music which generated a beautiful pattern of switching transients. Provided you notch out roughly +/-2 kHz then these transients can only beat with each other to produce stray audio. Even for a pure tone these are only a functional of the duty cycle, switching frequency, input audio frequency and input audio amplitude, so will just sound like anharmonic noise. Fair enough, until someone rocks up on this thread who can clarify whether it's an LC shunt or more complex LP filter that's in use, no-one can say for certain, and I'm not sure anyone monitoring this thread is very much interested either. Deck chairs, Titanic, etc.... |
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#154 |
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Join Date: Apr 2011
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Quote:
You really know nothing.
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#155 |
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Join Date: May 2004
Posts: 13,570
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Quote:
RTE on 252 broadcast in AM.
Pulse AM is something different. But with the low listening to 252 still a high cost per user and RTE is still saying it will be switched off in 2017 with existing users moved to digital (online and satellite). The 10 year old transmitter could be sold and work on MW, India might be a buyer if it is still capable of DRM. But with decomissioning, transport and reinstall is it worth it?. |
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#156 |
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Join Date: Feb 2011
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Quote:
Would you care to expand. Rather than just post your usual vague notions, inaccuracies and useless rubbish.
It is AM. That is it. What you see in the waterfall of 252 is exactly the same as what you will see in the waterfall of a "conventionlly" modulated AM ttansmitter. The only inaccuracies are in your posts. |
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#157 |
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Join Date: Feb 2011
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Quote:
Looking at the soec of the 2007 Transradio 252 transmitter it does have PDM Pulse Duration Modulation which is equivalent to PWM Pulse Width Modulation or PulseAM which makes the AM transmitter more effecient.
But with the low listening to 252 still a high cost per user and RTE is still saying it will be switched off in 2017 with existing users moved to digital (online and satellite). The 10 year old transmitter could be sold and work on MW, India might be a buyer if it is still capable of DRM. But with decomissioning, transport and reinstall is it worth it?. Pulse AM is different. |
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#158 |
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Join Date: Apr 2011
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Quote:
...The 10 year old transmitter could be sold and work on MW, India might be a buyer if it is still capable of DRM. But with decomissioning, transport and reinstall is it worth it?.
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#159 |
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Join Date: Feb 2011
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Quote:
I thought that the DRM modulator was a retrofit and had been flogged off since? Would be interesting if it were still kicking around at Clarkstown.
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#160 |
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Join Date: May 2013
Posts: 242
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Any update on the "consultative steering group" that RTE are working with ? The campagain to save 252, move to 261 etc seems to have gotten very quiet recently
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#161 |
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Join Date: Jan 2015
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Is there actually any campaign to move to 261, outside of this and maybe a few other bulletin boards?
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#162 |
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Join Date: Feb 2011
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Quote:
Is there actually any campaign to move to 261, outside of this and maybe a few other bulletin boards?
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#163 |
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Join Date: May 2013
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Quote:
Is there actually any campaign to move to 261, outside of this and maybe a few other bulletin boards?
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#164 |
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Join Date: May 2004
Location: southern Ireland
Posts: 126
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RTE's 252LW due to have an outage for several hours from around 10AM this Wednesday: according to http://www.rte.ie/aertel//desktopxhtml/169-2.html Quote:
Due to essential maintenance work, our Summerhill transmitter will be off the air from 10:00 to 17:00 on the 23rd of November 2016 .
This work will affect the Radio One Long Wave service from this site. 2rn apologise for any inconvenience caused by this necessary work. |
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#165 |
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Join Date: Jan 2015
Posts: 2,448
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Maintenance? On something due to close? Or does this confirm the reprieve?
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#166 |
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Join Date: Nov 2001
Location: Central Belt
Posts: 12,274
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Quote:
Simple answer, no.
Time to shutdown both Radio 4 LW and RTE LW and so end broadcasting on the platform in both the UK and Ireland. |
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#167 |
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Join Date: Dec 2001
Location: Hampshire
Posts: 8,078
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Quote:
RTE's 252LW due to have an outage for several hours from around 10AM this Wednesday:
according to http://www.rte.ie/aertel//desktopxhtml/169-2.html ![]()
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#168 |
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Join Date: Oct 2009
Posts: 476
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Why does Divid16 want to kill off long wave broadcasting? What is it to him how other people listen to radio?
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#169 |
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Join Date: Jun 2002
Location: Scotland, Dunfermline Area
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Some newer radios in the last few years don't seem to have LW band anymore. The just have FM/AM(MW) or in some cases just FM/DAB.
I still got an old portable battery radio that I got in the late 90s that I hardly ever use anymore and that has FM/AM(MW)/LW and Two short Wave bands. Darren |
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#170 |
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Join Date: Jan 2010
Posts: 9,204
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Quote:
Some newer radios in the last few years don't seem to have LW band anymore. The just have FM/AM(MW) or in some cases just FM/DAB.
I still got an old portable battery radio that I got in the late 90s that I hardly ever use anymore and that has FM/AM(MW)/LW and Two short Wave bands. Darren |
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#171 |
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Join Date: Mar 2004
Location: Glasgow
Posts: 1,544
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Quote:
Why does Divid16 want to kill off long wave broadcasting? What is it to him how other people listen to radio?
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#172 |
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Join Date: Sep 2005
Posts: 2,436
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Quote:
any LW opt-outs of BBC R4 on LW are carried on DAB> as a secondary service.
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#173 |
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Join Date: May 2004
Posts: 13,570
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Like 252 closing in 2017, (the maintenance will keep the site going untill 252 listeners go to internet or satelite and the outage will give a chance to see who complains about the break), notice on 198 was given in 2011 that it will close in about 10 years or if the transmitter is too expensive to repair http://www.radiotimes.com/news/2011-...ion-must-mourn Quote:
we're going to lose BBC Radio 4 on 198 longwave. Maybe not today, maybe not tomorrow. But sometime - and the BBC isn't quite sure when, because it depends when the equipment next breaks down.
Most likely when the electric switching contract ends iin 2021 and more boats get Navtext and satellite warning systems.
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#174 |
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Join Date: Nov 2005
Location: Back of beyond
Posts: 1,928
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Quote:
Most likely when the electric switching contract ends iin 2021 and more boats get Navtext and satellite warning systems.
I'm lucky --- I have a hand held VHF radio and a local Coastguard mast .. Regards |
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#175 |
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Forum Member
Join Date: Dec 2009
Posts: 25,460
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Quote:
Not correct: the noon shipping forecast is LW only, and Yesterday in Parliament is often LW only when there aren't enough bits available, e.g. during pop-ups.
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