And I wonder what would be heard on a regular FM radio eg. a buzzing noise or something…
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That’s a bit of a shame - as the ideal implementation would be the ABC FM transmissions carrying the additional services or any AM services in DRM+ mode.
A bit odd to be in the FM band and not utilise the simulcast ability - maybe that’ll come later.
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Most of the shortwave radio listeners & dxers who want to decode DRM (on shortwave) use a SDR with appropriate software - it’s a much cheaper option given the limited selection of DRM specific radios.
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I wonder if VHF Band I could be used for DRM+? AFAIK the spectrum hasn’t been reallocated. You would need to carefully plan services to minimise interference due to E-skip in summer, though.
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Indonesia trial results of DRM on FM earlier this year.
https://www.drm.org/drm-for-fm-measures-up-to-expectations-in-indonesia/
If DRM is used in the VHF Band II it only utilises a 96 kHz that can accommodate up to three audio channels and one data channel. This was also demonstrated by RRI in their trial conducted with the DRM Consortium in Batam. So, half the spectrum for up to three audio channels and one data channel, rather than one analogue audio only programme in FM.
In Indonesia FM is widely used in large cities, so there are not many FM radio frequencies available now. To avoid interference between FM radio broadcasts, the FM broadcast radio frequency channel is ideally separated by 400 kHz (adjacent-4). As DRM can fit in these guard spaces DRM can be a solution even in the cities with a very congested FM spectrum.
Based on the results of the field measurements obtained in the six test points covered by the 1kW transmitter it was noted that these can be served with only 50 watts of DRM power delivering throughout a good DRM audio quality. In testing a simulcast broadcast using 1 kW and 800 Watt with spacing distance 150 kHz between the middle frequency FM and DRM, the measurement showed no interference between FM and DRM.
I have read that there are new DRM modes coming for AM and FM and new codecs will be needed for SDR radios.
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In Canberra so can give an update on all Canberra dab+ bit rates.
2CC 64kbps
ABC CBR 64kbps
ABC Classic 80kbps
ABC Jazz 80kbps
ABC Kids 72kbps
ABC Country 80kbps
ABC Grandstand 40kbps
ABC News Radio 48kbps
ABC RN 64kbps
Chill 72kbps
Arabic 24 48kbps
Art sound 64kbps
Club line 64kbps
CMS 48kbps
Coles Radio 32kbps Mono
Double J 80kbps
Hit 104.7 112kbps
Hit Budda 80kbps
Kix 64kbps
My Canberra 96kbps
Mix 106.3 112kbps
Pop Desi 64kbps
SBS 1 40kbps
SBS 2 40kbps
SBS 3 48kbpz
SBS Pop Asia 72kbps
Snow Dab+ 96kbps
The Edge 80kvps
Triple J 80kbps
Unearthed 72kbps
1WAY 48kbps
2CA 96kbps
2XX 48Kbps
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Seems like Canberra’s the place to be for hi-fidelity DAB listening.
A bit surprised that more stations haven’t been jammed in yet - with bit rates crushed to buggery of course.
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It actually sounds really good, the best I have heard dab+ sound.
Snow Digital sounds almost as good as it’s fm broadcast. It sounded very tinny when it was at it’s previous low bit rate.
Canberra have got it right with their current dab+ bit rates, pity they are not at 50kw for extended highway coverage and better dxing opportunities.
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Other than Coles radio, it’s great how they stuck to high fidelity rather cram lots of stations in.
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I am happy with the improvement from 5kW ERP max spec to practical operation at 18.3kW ERP, just off the 20kW max spec.
It has resulted in significant improvement to fortuitous coverage along the Hume, better on the fringe in Yass and further afield, Boorowa which had patchy coverage, it’s now like a local.
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Thanks @littlegezzybear for finding this significant addition to ACMA’s database.
Mt Baranduda is the main site for the Upper Murray, cross border region of Albury/Wodonga.
DRM+ works on both AM and FM and the many megahertz in between each broadcast band.
Band I VHF would be perfect as suggested.
The SW TX at Tennant Creek was fairly new at time of the closure of the ABC’s domestic HF services and it was also capable of simulcasting in DRM+ yet sadly never did. What became of that TX I wonder?
It’s fantastic the ABC is trialling DRM+. Be it AM or FM or in between, it’s a start; a start that CRA will be unsettled by and that’s a good thing. CRA might eventually catch up.
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DAB+ is still patchy around Boorowa on my car radio; it could be better on other receivers. Yass is no problem. To the south I get continuous coverage to Michelago but it’s very patchy after that. I usually switch to XLFM at Michelago as a result.
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On my portable device Sangean dpr-35 it is pretty solid until Williamsdale. How far towards Goulburn does the car get Canberra dab+?
My limit on my portable is Collector with the exception of the Gib. I wish my Tuscan radio had dab+ my model was the one before it was included as a standard.
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In my experience, to the top of the Great Dividing Range, so somewhere near Wollogorang (which is a few kms north of Collector).
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I would have thought the car radio would have had greater range then that considering my portable has patchy coverage to Collector.
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Going down the other side of the range generally blocks the signal from Canberra.
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Canberra dab+ would be possible at the top of the hill along the Motorway near Mt Gray, (Southern LOS) Canberra fm is quite good there. My portables signal bars lit up but not enough to decode dab+ on previous trips.
96.1 XL Fm was quite strong there today but quickly faded on the northern side of Mt Gray, and in came the Edge 96.1.
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Yes I can get it here. DAB Coverage is better along the Tarago- Braidwood Road than the Federal; I can listen almost all the way to Goulburn on the former.
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Disagree. I reckon it’s a colossal waste of time and taxpayer funds, especially given other ABC cutbacks.
It’s been 10 years with DAB+ and let’s be honest, hardly anyone’s listening. It’s taken car manufacturers about this long to get DAB+ in new cars now. It’ll take at least another 10 years for DRM+, assuming they even bother. Cars are beginning to have wireless modems in them now (see the new Ford Ranger), almost certainly bypassing any need for digital radio. Good old AM and FM still hanging around also.
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It depends on what you think is the long term play from Commercial broadcasters.
The ABC have a risk of essentially being roped into funding regional commercial DAB - through the nature of how DAB would need to operate in regional areas.
Only having two multiplexes set aside for use by the ABC means they can’t provide the correct ABC Local Radio service into each market (potential for DAB windowing aside) - as such, the most logical path is to utilise Category 2 licenses for the Commercial multiplexes in each market.
That then means, the ABC/SBS would need to pay, not only their costs of broadcasting the ABC/SBS multiplex, but also pay the Commercial Multiplex operator, a share of the costs of transmitting their localised services on the local Commercial Multiplex. And if you’ve only got one or two other operators in the market - the ABC’s share of that cost would be relatively high.
So you could get to a circumstance where a rollout of regional commercial DAB+ is heavily funded by the ABC’s need to use those multiplexes to carry a localised signal into each market - due to how unsuitable DAB is.
As such - the ABC testing DRM+, a Digital Radio platform they’d be in full control of and would meet their needs far better at delivering local digital radio services to regional areas, even if no permanent DRM+ services come of it, is a useful investment to prevent them becoming burdened by subsidising commercial radio transmissions.
Luckily, there’s essentially 0 desire among commercial radio operators to move to digital in regional areas, so this scenario need not occur - but I think the ABC get a lot of value by ensuring DRM+ remains on the table, and they aren’t forced to bear the costs of an unsuitable rollout of DAB.
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