Hello all,
I wounder if any of you have listened to DRM broadcasts on SW or MW and what did you think of it ?
I listen once in a while via an internet SDR, e.g.
http://sdr.gb0snb.com:8073/ which has a DRM extension.
The audio quality is very good but it seems there are only a few national broadcasters (e.g. the BBC) using DRM and with a very limited number of hours per day.
Sadly, I think DRM is too little too late now that the world has moved to the internet.
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I think you are most likely right, you can listen to anything you like now either downloaded or streamed. I had responded to a post on here about the closure of Long wave which made me think of the DRM thing
Brad
You probably mean the BBC R4 LW transmissions rather than the LW broadcast band itself. I understand the Droitwich transmitter uses antique valves that are no longer manufactured and that the BBC even had to purchase the entire global supply of these valves. But it seems year on year budget cuts are forcing the close down of this very expensive transmitter well before it gets through the last of those valves.
The Beep is one of the last European LW broadcasters - the end of an era.
Ghostly carriers from former European LW broadcasters leaving only BBC with meaningful modulation.
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Well⌠such valves are not production items you buy off the shelf. Theyâre made to order. And Iâll think youâll find that when those valves age they get swapped out for the spare ones and the tired/worn ones get sent back to Eimac/Thomson etc. for remanufacturing. The story from the BBC doesnât match with what my friends who work in high power TV/Radio broadcasting have said. Now it may well be the cost of remanufacturing is becoming unsustainable to the BBCâs limited coffers but thatâs not the same as no more valves are available.
I would hazard that the number of listeners (excluding data service users) of LW broadcasts is miniscule in comparison with other systems and as such is very difficult to justify when politicians and other broadcasters are trying their best to financially strangle the BBC. e.g. ever seen a pro-BBC article in any paper owned by mega-private broadcaster Ruper Murdoch? That 500kW TX (is 500kW carrier) and itâs not a modern AM transmitter so itâs not going to be massively efficient, the opposite in fact. So given that nobody listens to it, there are no data users of it, shut it down and bring down the masts. Look at where it is on the map and that land is worth gazillions to house builders. Thatâs why I predict, slow death, then shutdown, then demolish the masts followed by a few thousand rabbit hutch houses. Trebles all round for Arqiva!
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I would guess the same end for Longwave in the UK Woofererton broadcast on DRM every morning but only for one hour on SW 5.7mhz approx Iâm guessing as DRM is bigger in India that is what they are aiming at. Where I live FM ,DAB and mobile streaming are a pain in the butt with the signals chopping in and out due to the terrain. When I heard about DRM I had thought that there may be a new life for MW/LW with only a few transmitter sites being needed to cover the UK rather than the Hundreds maybe thousands as is now. That said I think people listening to radio is a dying thing full stop, I occasionally listen to Radio 4 Long wave Farming today program on my way to work but as most radio stations just broadcast total garbage all day that is about it ! The rest of the time Iâm listening to pre downloaded Podcasts on subjects I have an interest in .
Thatâs your opinion but radio is certainly not dead. I listen to the radio at meal times and itâs often on all day at the weekend. Itâs certainly true that many people listen to it via streaming rather than broadcast, but I donât think broadcasting is dead just yet. Itâs true that I no longer listen to Radio 4 Extra because I can just pick whatever I want on BBC Sounds and listen to it on my Bluetooth headphones.
Radio 2 coverage here in the Yorkshire Dales is pretty good. The car will seamlessly switch between FM and DAB and itâs only when I get to the far reaches of Langstrothdale (which is the name for the very top of Wharfedale) that the signal struggles. As soon as I gain some height the signal is perfect again. So my worry is that they will decide to switch off FM once DAB has sufficient listeners - I hope they convert the FM transmitters to DAB to get the same rural coverage.
But back to your question. There arenât many transmissions and not many receivers. I can see the signal on 15170kHz from Romania but I canât get the DRM plugin for SDRUno to decode it. So no!
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There is an option in the IC7300 to route IQ output over USB to a PC and decode DRM using a program called âDreamâ ( Dream AM/DRM Receiver download | SourceForge.net ) if you prefer to receive locally rather than via a WebSDR. The last time I did this was probably 10 years ago, so I havenât used the latest version of this software on Windows 11.
73 Ed.
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This should also work with the QMX.
73 Chris
Some of the DAB stations have already âswitched offâ for me having gone from DAB (MP2) to DAB+ (AAC) so my older DAB radios display the station ID but thereâs no audio. I know it took forever for European nations to agree the DAB standard but why MP2?; I feel sure the MP3 standard was around by then.
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You realise just how crud MP2 (at UK DAB bitrates) was when you hear AAC DAB. Then you switch back to FM and realise how crud AAC at UK bitrates is.
Iâm sure youâre right though Iâve never done an A vs B comparison. DAB+ uses HE-AAC which is optimized for low bitrates. AAC music files for downloading use higher bitrate (e.g., 256kbps or 320kbps) and are close to near-CD quality audio. But AAC is lossy by definition (i.e. spec).
The biggest step in quality was when I first heard CDs in 1983/4. It made my vinyl LPs sound crap by comparison despite my fancy hi-fi deck, dust-bug, etc.
More controversially, I prefer the audio quality of N-FM (e.g. on my Yaesu 2m HT). You can hear the effect of quantization on the audio in C4FM mode. Even W-C4FM [which nobody uses to call CQ] doesnât sound quite as good as analogue FM.
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Additionally, the Xiegu G90 features an I/Q output, which should also be possible to use for DRM reception decoding.
73 Ed.
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I know Broadcast receivers are normally deaf as a post but DAB is terrible near me despite multi kilowatt transmitters in nearly every direction . I can reach all these locations on 1 watt into a home brew Dipole in the attic on 2 meters which I find really odd. The other problem is being an Old Rocker the few stations I do get just donât suit my taste at all. I am in the sticks in Shropshire and the DAB radios I have are quite old so probably an older format but even when I lived in the city the quality was naff. Is DAB+ actually any better ?
DAB is capable of high quality but instead they cram as many stations as possible into the multiplex. Quantity over quality. Itâs the same with TV - there are hundreds of channels on satellite and cable but I still struggle to find stuff worth watching.
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Just how many microprocessors are needed to receive todayâs radio sevices?
In the past, a Catâs whisker was good enough 
73 Dave
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Unfortunately, there are some conditions that do not support itâŚ
- there are no drm receivers on the european market. Even the Chinese do not seem to produce them in a big amount⌠However, they produce for Australia, but receivers are too expensive ⌠around 500 Australian Dollars.
- regular SWLs will not use software based solutions. Even these solutions are not straight forward.
- currently the propagation conditions are not very good⌠at least for central Europe.
- for these conditions the TX power of many broadcasting stations is unfortunately more experimental⌠not enough
- and there are not many SW broadcasting stations, e.g. BBC, RRI, âŚ
Since DAB/+ is the promoted solution for Europe, DRM does not seem to have a chance⌠But there are no DAB broadcasting stations on shortwave eitherâŚ
73
Ingo
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DAB failed entirely in Ireland. DAB+ might prove more popular though.
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The problems I have with DAB was two things. Technically, you can radiate a lower power signal for the same effective SNR because of the clever modulation and error correction built in to the coding. This means most DAB is broadcast at significantly lower powers than FM. That saves the broadcasters money. But it doesnât seem to be broadcast at a strong enough level and most DAB receivers seem to be deaf as a post. The downside is as I drive my car around Scotland the DAB signal is in and out but if I switch to FM, I get a usable signal when there is no DAB. Now Iâm not talking thereâs no DAB up at Cape Wrath but there are areas in and around Edinburgh and Glasgow where thereâs no DAB. Flip to FM and I have a fabulous end-stop FM stereo signal. And weâre talking the same experience on a pair of cars described as âexecutive coupeâ and âexecutive sedanâ not entry level super-mini hatchbacks. The second problem is the total and complete greed of the broadcasters to fit as many stations as possible into the DAB channel bandwidth. This was done by reducing the bitrate and transmitting in mono. Couple low bitrate to MP2âs poor performance at low bitrates and you have something that sounds dire and significantly inferior to the FM signal itâs meant to replace. Time after time when people have complained that DAB sounds terrible, politicians and broadcasters have dismissed those complainst as coming from snobs and âhey never mind the quality look at the sheer choiceâ. Except there is no choice since Bauer Media bought up all the local commercial stations and have them all transmitting the same program and only the advert breaks are different.
To keep the cost down, many DAB receivers are hard coded. DAB is a software system but selling DAB receivers that can be OTA upgraded or capable for future enhancements is damnded pricey compared to a hardcoded solution. So We had a sub-standard CODEC (MP2) force on us and greedy broadcasters trying to cram a quart into a pint pot and then were told when we complained that itâs wonderful. DAB+ is a big improvement. But FM still sounds better.
Do a simple test, listen to The Archers on FM and then on DAB. On FM there is ambience and spatial sense of a soundstage with voices and sound FX placeable on a left to right basis. And on DAB it sounds dead and lifeless⌠because of mono and too low a bitrate.
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A proper DAB+ signal produces much better quality audio signal than FM signals. Listen to some classical music and you will hear the difference. However, the UK used to implement DAB only⌠No DAB+⌠Donât know how it is now⌠And with DAB devices I had problems in DAB+ reception areas⌠It might have changed âŚ
73
Ingo
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