tag:blogger.com,1999:blog-5972592.post7314581654212048243..comments2023-09-19T17:44:32.648+02:00Comments on Media Network Series Two: Death of Digital Radio Mondiale in 2008 as well?Jonathan Markshttp://www.blogger.com/profile/10649569693082320105noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-5972592.post-54295221398550732622013-02-04T08:38:06.573+01:002013-02-04T08:38:06.573+01:00It's a real shame DRM has died because it was ...It's a real shame DRM has died because it was (and is) capable of lots of things;-<br />crystal clear stereo and mono audio,<br />good robustness and integrity against interference,<br />a host of good features like pictures and text within the broadcasts,<br />the facility to timeshift your favourite programmes,<br />on demand content,<br />and an ease of use that's simplicity itself.<br /><br />The thing that dog DRM is;<br />the closedown and dismantling of AM transmitter sites,<br />discontinuation of AM broadcasts via SW and MW, <br />inadequate power transmission, <br />highly directional transmission beams and<br />refusal to manufacture the sets to receive it.<br /><br />If european broadcasters used better power for their transmissions say 90-150kW for SW/240-300kW for MW in DRM mode and used 360degree omnidirectional transmitter beams with decent bit rates etc and the setmakers brought out decent portable and car stereo sets to support the DRM format, it would mean you could stay tuned all over Europe in the car and at home or on the move to your favourite station without retuning and coverage would be much larger than it was.<br /><br />I have heard drm at consumer electronic fairs and i'am pleasantly surprised at how good it is over analogue AM and on SW you can easily cover continents and large areas and cover counties single countries territories and cities on MW.AnthonyUKhttps://www.blogger.com/profile/10517374999742576649noreply@blogger.comtag:blogger.com,1999:blog-5972592.post-78423346531708143442008-07-31T19:20:00.000+02:002008-07-31T19:20:00.000+02:00All forms of digital radio around the world are st...All forms of digital radio around the world are struggling, as it does not give listeners enough reason to upgrade to new, expensive receivers. Dropouts, poor coverage, and interference are drawbacks. It appears that the drm.org site is all but dead:<BR/><BR/>http://siteanalytics.compete.com/drm.org/?metric=uvAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-5972592.post-43144053792648328892008-04-17T22:40:00.000+02:002008-04-17T22:40:00.000+02:00I second the comments regarding the vulnerability ...I second the comments regarding the vulnerability of internet radio. Due to the fact that the internet has more linkages to it, there are more ways to disrupt or wreck it than long distance broadcasting, such as shortwave. To allow the shortwave transmission and radio industry to fade away, along with Ham radio, is to leave the communications system without backup, especially for emergency situations. I agree the sound and signal of shortwave can be an issue, however, the purpose of long distance communication is not just for hi-fidelity, but to make sure that one is heard no matter how unattractive the sound. <BR/>Furthermore, the decline of the content in programs whether on shortwave, (or AM or FM, in the United States) is a major reason why some audience members do not have the interest to listen any more. Perhaps I'll buy the WiFi, but I hope the shortwave in the desk drawer will have the transmitting stations to pick up when the power or internet is out, or worse.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5972592.post-21075331265104747442008-04-05T05:49:00.000+02:002008-04-05T05:49:00.000+02:00I was just reading the WinDRM group (which lead me...I was just reading the WinDRM group (which lead me here) and noticed on the "death of DRM" the main complaint (beyond lack of DRM radios) is that the 12.khz signal is a pain to convert & feed into software decoders (which I collect and test)<BR/><BR/>DRM+ solves the problem - any radio channel who's bandwidth exceeds whatever DRM is set to (while 12.khz is typical there are many choices, from 4.5 to 20.khz) makes it effortless to feed the audio to a software decoder.<BR/><BR/>Myself I use a version of FMeXtra (DRM+ over wideband broadcast FM band SCA channel) and WBFM on (high power) UHF which works especially well - I successfully obtained the full 72.kbps/20.khz mode recently doing this..<BR/><BR/>Also, encoding DRM being a rather high CPU load, I simply record the audio DRM+ signal and *even encoded to MP3*, thus playing on a portable MP3 player, 2-3-4 hour blocks of music.<BR/><BR/>If you pick your MP3 encoder & bitrate carefully (blade 256.kbps mono) it causes no loss of signal-to-noise ratio compared to the raw wav. The next best is lossless compression..<BR/><BR/>On UHF almost everyone uses NBFM scanners and so this WBFM signal sounds like noise (pretty stealth) - I do this on purpose. <BR/><BR/>But you can reduce the modulation to NB and allow any ordinary scanner to demodulate a clean decode signal too. (14.kbps is about the limit in this case as the 455.khz filters don't allow much deviation to maintain a decent S/N ratio)<BR/><BR/>A man in NZ has developed a simpler soundcard software QAM en/decoder which has UDP/serial port access and also uses the Unreal server/player that allows you to broadcast live video. Plus it has auto-web (files) sending on channel idle..<BR/><BR/>The possibilities extend to POTS modems audio fed over radios and PPP/IP linking but this is a 2-way connection (although the backchannel can be a much lower baud) These modems are generally going to waste otherwise, plus you can set up these links without tying up computers - you end up (in the case of external modems) with simple serial data.<BR/><BR/>While I don't mess with AM or lower frequencies there's nothing stopping a person from directly modulating a transmitter and thus no conversion would be needed.<BR/><BR/>I had one person argue that DRM isn't "meant to be used this way" and that direct modulation loses the advantages COFDM re: fading/doppler/static.<BR/><BR/>Maybe, but I can say DRM+ works quite well on FM<BR/><BR/>SCA channels tend to have bursts of static (mostly due to slight overmodulation peaks or multipath) and is quite like AM. DRM with strong FEC ignores this - better than anything else I've tried other than FSK at a low baud (like Bell 103), and gives by far the best throughput under such conditions. The best modems can do is an unreliable 14.4 to 19.2, while DRM gives a solid 14.2 and can be pushed to 21.kbps or so..<BR/><BR/>DRM is roughly twice as good as all other modulations I've tried (which are quite a few)<BR/><BR/>This QAM software is almost as good, but is much more flexible in what you can send with it :<BR/>http://homepages.paradise.net.nz/peterfr2/QAM.htm<BR/><BR/>I didn't join google groups to relate this info - perhaps someone here could mention this there for me ?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5972592.post-78536968247587523832008-03-18T00:53:00.000+01:002008-03-18T00:53:00.000+01:00Hi Eivind,Thanks for the feedback. You're right in...Hi Eivind,<BR/><BR/>Thanks for the feedback. You're right in that the user interface on the DRM sets seems to be poor. I had enormous drop-out problems on the RTL tests. <BR/><BR/>I appreciate you taking the time to comment. I know some people at Trondheim University, so may be coming your way some time. I'm told the northern lights there are superb...although not at sunspot minimum I guess. MW must be great.Jonathan Markshttps://www.blogger.com/profile/10649569693082320105noreply@blogger.comtag:blogger.com,1999:blog-5972592.post-44666014918973396922008-03-18T00:05:00.000+01:002008-03-18T00:05:00.000+01:00From Eivind Motland, Norway:I have a Himalaya DRM ...From Eivind Motland, Norway:<BR/><BR/>I have a Himalaya DRM 2009 receiver, which is a good radio receiver both in design and reception.<BR/><BR/>However, while I am used to search frequencies more active because I am a radio dx´er and satellite enthusiast, I have no problems doing the active searching. But on the DRM bands the autoscan is close to useless because there are only a handful DRM frequencies which will be stored when doing this. Most of the DRM transmissions have to be stored by searching the frequencies manually - and then you have to read the Live Broadcasts Schedule on the DRM website to know which frequencies are active at the time.<BR/><BR/>Second, I live in Trondheim in the middle of Norway. Norway is of course part of Europe, but the DRM transmissions with coverage area "Europe" (like BBC WS and DW) are not receiveable here. So there we go - the DRM coverage area is smaller than with conventional AM. The funny thing is that I have an outdoor external antenna on this radio. Both FM and DAB have good reception, and reception on conventional AM is excellent. But the only improvement on DRM is that I can receive some more data signals from i.e. WDR Langeberg 1593. But do I receive any sound? No way!<BR/><BR/>I like the thought of digital AM and DRM, but I find the DRM solution of today very bad. The dropouts are annoying, and I do actually not get anything up here on my DRM radio.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5972592.post-24884289132206354642008-02-29T13:48:00.000+01:002008-02-29T13:48:00.000+01:00I think you're story is actually very indicative o...I think you're story is actually very indicative of shortwave listeners in developed parts of the world - and a lot of the developing world if we're honest about it. The cleverer broadcasters have identified who they want to reach, where they are, and what media they are using. That is no longer shortwave radio. In countries I am working in West Africa, the FM relay is essential, even though the shortwave sets are on the market for 5 bucks, their performance on all but the strongest of stations is fair to lousy. Switching to FM, which brings music and much better fidelity is a breath of fresh air. And the local stations do the local languages. In Burma, Zimbabwe, Sudan, and a handful of other countries shortwave is probably still essential - although satellite TV is being watched intensively in Burma and Iran.Jonathan Markshttps://www.blogger.com/profile/10649569693082320105noreply@blogger.comtag:blogger.com,1999:blog-5972592.post-80326540042559579372008-02-28T15:34:00.000+01:002008-02-28T15:34:00.000+01:00I don't know if my personal experiences can be cou...I don't know if my personal experiences can be counted as a sort of "canary in the coal mine", but I can tell you that even I--a former dyed in the wool shortwave listener--have shifted most of my listening to satellite radio (XM/Sirius), podcasting and--now--wifi internet radio. The last one surprised me, to be frank. Internet radio has been available to me for years via my desktop and laptop computers, but I've accessed it that way only sporadically. On a whim, I purchased a wifi radio (Com One Phoenix) about six weeks ago. It runs on rechargeable batteries and it follows me around the house almost constantly. As you say, the better quality audio (at least on many, if not all, stations), better content at greater variety, and ease of use all contribute to a much more satisfying experience than what I can get today from my old friend shortwave. Podcasting extends the experience to my daily walks; satellite to the car. Sadly, there's hardly any room for shortwave--especially sad because I own about two dozen radios. I still worry about the very real potential for interdiction of all radio not delivered by analog shortwave--that characteristic of shortwave remaining its only tangible benefit over the other platforms. In sober moments, it should be recognized as a significant concern; but in all the euphoria over the alternatives it gets lost in the discussion quite readily. As with many things, we all may just have to learn the hard way on that one.Unknownhttps://www.blogger.com/profile/03112663736324416408noreply@blogger.com