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Old 21-12-2013, 04:18   #286
tpreitzel
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I was just reading a website located in the UK devoted to DRM. On their page for the future, it listed one closure after another since around 2005 or so. I was thinking to myself that this guy doesn't really get the message. DRM won't necessarily stop realignment of services nor should it. Countries in debt (all of them due to Keynesian economics) have to look somewhere for savings. Personally, I applaud the closures due to overcrowding on the shortwave bands, but I think dismantling of facilities is nearsighted. I breathed a sigh of relief when REE suspended broadcasting DRM from Cariari since one of their frequencies to SA was interfering with VON's broadcast to NA. We actually need MORE closures as shortwave broadcasting becomes leaner (enabling 20 kHz channels), cleaner (digital), and meaner (more services). I'm looking forward to 2014 as the year of digital radio when broadcasts in DRM with the xHE-AAC codec, new receivers, and better service finally become available to the SWL. Use the time of this current transition wisely to prepare for 2014. I wish everyone a Merry Christmas as 2014 ought to be exciting for digital radio even though many of you have waited patiently for nearly a decade.

I wonder if this transition date for DRM on MW is still valid in Spain?
http://www.drmrx.org/forum/showpost....&postcount=241

Last edited by tpreitzel : 22-12-2013 at 05:00.
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Old 25-12-2013, 11:40   #287
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This is just true http://drmradio.co.uk/drm_019.htm but only part of the story.
A more complete list of closures is http://de.intervalsignals.org/kurzwelle/niedergang.html though in German.
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Old 25-12-2013, 12:19   #288
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btw.: Does the BBC believe in future of DRM in Asia?
http://swling.com/blog/2013/11/bbc-a...relay-station/
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Old 28-12-2013, 10:54   #289
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I'm tempted to link to the Rolling Stones' hit, "Doom & Gloom"...

DRM should have no problem surviving nor should other alternatives such as radiograms.

I've been experimenting with VOA's Radiogram. Versions of DReaM with Speex noise reduction (2.1+) complement the limited bandwidth of radiograms very well indeed. It's refreshing to listen as the Speex noise reduction literally wipes the noise from the radiogram and leaves the digital tones of MFSK intact.

Here's a proposal for a low-cost alternative to DRM:

First, incorporate MFSK-32 (text) and MFSK-64 (images) into a portable shortwave and MW receiver along with a restricted graphics' display of 320x240 pixels or so. Second, incorporate the excellent Speex noise reduction from DReaM into the receiver. Enable the receiver to automatically detect, clean (noise reduction), decode and display the original text and graphics from the MFSK-32/64 signal on both shortwave and MW bands. * Personally, I'd LOVE to own a portable receiver with such capability as a complement to my DRM receivers.

* Unlicensed LPAM

Last edited by tpreitzel : 29-12-2013 at 07:43.
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Old 25-01-2014, 12:45   #290
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The German magazine (Jan 2014) Infosat has an article about DRM, or should I say, the lack of DRM:

Digital Radio Mondiale (DRM): Leistungsstark und nicht gewollt
Wer zu den wenigen Besitzern eines DRM-Radios (Digital Radio Mondiale) gehört, hört auf diesen Wellen im Moment nicht viel. Radiosender in Europa haben sich vom DRM-Engagement enttäuscht zurückgezogen. Selbst einstige Befürworter wie Deutsche Welle oder Deutschlandradio sind ausgestiegen. Dabei ist das Potenzial groß, wie ein Blick nach Asien zeigt, wo Digital Radio Mondiale dabei ist, alle anderen Radio-Empfangswege in den Schatten zu stellen.
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Old 07-02-2014, 00:13   #291
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Will Wave Modulation Replace QAM?

First, I thank Alokesh for posting this link on his blog, Radioactivity. I'm not denigrating the search for better use of bandwidth and it's encouraging to see such research continue. DRM isn't perfect, but it's good enough. IF this allegedly new form of modulation is significantly superior to QAM, is it NECESSARY? My answer is no. With the advent of more efficient codecs like xHE-AAC, digital systems based on QAM like DRM will suffice just fine without WAM.

WHAM!

http://electronicdesign.com/blog/new...-method-really
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Old 07-02-2014, 12:23   #292
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Hi
I think that mixing modulation modes and lossy codecs performance is a mistake.
There is also error correction that needs to be taken into account.
DRM is one of the best ways to mix those different things for broadcasting.
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Old 09-02-2014, 01:33   #293
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Cool

Having looked into the details of 'WAM' thanks to the tips from tpreitzel, I think it might be interesting to put the all the elements into perspective:

Under the ideal channel conditions (AWGN) the DRM system will support approximately 30kbps @10KHz bandwidth@15dB SNR (the bitrate might looked a bit higher because I'v factored in the OFDM guard intervals in order to compare apples to apples). Now under the same channel conditions, the theoretical shannon limit will be: Bwlog(1+SNR) = 50kbps. So the spectrum effiency would be 60% for DRM.


Now, suppose we change the multilevel convolution code to TurboCode/LDPC which is already deployed in the state of art communication system, that will give you a 3dB edge (If my memory no fails me), that translates to an extra 10kbps payload, ie. total payload would be 40kbps. So, even if the promise of 'WAM' is real, it can give you at MOST 10kbps 'cause that is theoretical limit!!! The question is: Do you really think the extra bits worth the hassle yet again???

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Old 04-03-2014, 05:58   #294
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An Indian official, Prasar Bharati chief Jawhar Sircar, wants to junk the current implementation of DRM in India. Personally, I think his idea is silly, but enjoy the controversy as it seems like a big joke to me.

http://www.newkerala.com/news/2014/f...l#.UxV1gNdtvIw

Last edited by tpreitzel : 04-03-2014 at 06:37.
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Old 04-03-2014, 13:51   #295
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Thanks for the link
It seems that time goes backward over there.
http://en.wikipedia.org/wiki/Satelli...ion_Experiment
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Old 04-03-2014, 15:22   #296
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Perhaps DRM is too complicated for those Indians?
A well-known CEO (of Indian origin) tells his shareholders as well as employees that "reverse innovation" and "keep it simple" are the real goals for "emerging countries":
http://leadingcompany.smartcompany.c...rk/20120501864
http://blogs.hbr.org/2012/03/reversi...se-of-dominan/
Then Jawhar Sircar would be right ...

Last edited by DRM-OM : 04-03-2014 at 15:29.
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Old 04-03-2014, 15:59   #297
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Hi
On the contrary instead of giving/selling them ready made receivers
computers based solutions could help them even if there is no programs.
DRM with it's ability to distribute data and software is the good solution.IMHO
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Old 11-06-2014, 09:46   #298
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RTI appears to be testing with a decent configuration, but only time will tell. SWLs around the Pacific Ocean can expect some potentially nice reception.

http://alokeshgupta.blogspot.com/201...-drm-mode.html

http://youtu.be/FFDHbwf_RME

http://youtu.be/pRlTmbZG4wc

Apparently, the times have been sporadic from ~ 0330Z to ~ 0800Z ...
I briefly looked during this time frame, but no signal was present during my search.

Last edited by tpreitzel : 11-06-2014 at 12:52.
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Old 30-06-2014, 08:21   #299
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Start Me Up

Chicken Little cries, "the sky is falling!", as another STATE broadcaster, the VOA in this case, begins reducing their propaganda on shortwave ...

Here's one social axiom that won't be violated even by the state. Like pedophiles, propagandists always seek gullible victims so we can fully expect state broadcasters to follow their victims onto conveniently "popular" global networking platforms. Critical SWLs can breathe a huge sigh of relief as the shortwave bands are slowly cleared of state propaganda. Thankfully, this exodus won't be stopped except by a return of the masses to shortwave. Less is more as discerning broadcasters and listeners replace the propagandists and their masses on shortwave. Critical listeners everywhere should be celebrating the departure of VOA on shortwave, not mourning it. The slow uptake of DRM on shortwave just might be a blessing in disguise ... thank, God!

http://alokeshgupta.blogspot.com/201...asian-sub.html

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Old 04-07-2014, 20:22   #300
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On Radioworld magazine on June 2014 I found this: http://www.radioworld.com/article/si...dab-drm/270749
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