Not an issue technically, it’s done in Sydney. I assume it’s ‘who pays for it’ that is the problem….
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Here in Melbourne, the main DAB+ transmitters are 50KW ERP vs. 56KW ERP for citywide commercial/community FM stations and 100KW for ABC/SBS/Triple J.
One reason for the difference in coverage is that DAB+ is digital. With FM, as the signal goes past a certain point of weakness, it gets noisier but you can still hear the station. With digital, once you cross a certain point, the station goes from sounding perfect to completely undecodable. That’s one reason why.
One thing you can do with DAB+ that you can’t do with FM (there are exceptions) is to have repeaters on the same frequency as the main transmitter. So in parts of Melbourne where reception isn’t as good, you can have infill DAB+ transmitters on the same frequency as the main transmitters, so listeners don’t have to tune to a different frequency.
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Because they installed AM/FM retransmissions using lossy coax but haven’t bothered to do so for DAB due to the additional cost. Emergency message overrides are also more complicated with DAB than with AM/FM.
From my understanding, the DAB antennas point downwards slightly specifically to minimise overspill.
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DAB reception has been made available in the new West Connex and North Connex Sydney tunnels.
Since the power upgrade to DAB was switched on in 2016, the coverage has also been excellent in Sydney.
Some areas are better than others, but overall coverage is pretty good.
In the car , you can receive Sydney DAB near Woy Woy on the Central Coast, and as far west as Blackheath, in the Blue Mountains.
There was an issue with DAB reception on the Northern Beaches but this has largely been resolved with the power increase to 50kw ERP and infills at Bilgola Plateu and Collaroy Plateau.
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I can get DAB in Sydney until Victoria Pass just west of Mt Victoria now quite well. The advantage of height.
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Sydney Dab+ cuts out on our work trucks radio’s at the old Hume Highway exit of the Hume Motorway at Alpine. You loose line of site as you go down the southern slope of the hill towards the Southern Highlands.
Our work trucks radios are crap and have poor sensitivity on Fm and Dab+ so a car with a good fm/Dab+ radio would probably get extended reception.
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Sydney DAB+ is permanent reception in Bowral on my Sony if I take it out into the garden where I do my DXing on a regular basis although the digital cliff happens in a few parts of the garden. Was useful for listening to NRL while the local ABC had election coverage.
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What’s reception coverage?
I meant election coverage, sorry if I got confused
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I find it interesting that the main DAB transmitters in the capitals don’t reflect their related FM power levels.
In Sydney, FM is 150kw when DAB is also still only 50kw. In Brisbane the commercial FMs are only 12kw, but DAB is still 50kw. In Canberra the commercials and DAB are both 20kw…
I can’t work this one out!
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Maybe best to leave it up to the tech people to figure it out then 
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If memory serves me correctly, initially the Melbourne (and other state capitals) DAB+ transmitters were 12.5 KW each which was comparable to the digital TV stations’ power, given that it was 1/4 of the digital TV stations’ power of 50KW while occupying about 1/4 of the bandwidth.
Yes, though TV stations coverage areas are different to radio eg. Melbourne TV covers Geelong, whereas commercial radio doesn’t.
In terms of commercial FM radio, technically it does, much of Geelong and the Surf Coast can easily receive the Melbourne commercial FM stations alongside the local offerings. But yes not all of Geelong can get the DAB+ stations from Melbourne (although that can be fixed with a repeater of the Melbourne DAB channels somewhere in Geelong on different frequencies, much like TV) - Geelong radio can remain on AM/FM.
Technically, Geelong is outside the Melbourne RA1 licence area. Any coverage in Geelong and the Surf Coast is purely fortuitous. For that reason, there will never be a Melbourne DAB repeater in Geelong.
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Really? Explain the long-range reception of the Melbourne commercial FM offerings that get right down to Lorne (without ducting). And even there the signal strength is still quite strong enough.
Here’s a reference from a 2021 post discussing Mixx FM 92.7 Lorne being off-air…
OK so sure it might be outside the DAB+ license area for Melbourne but the FMs from Melbourne being heard in Geelong at local strength indicates the commercial FM offerings from Melbourne indeed cover Melbourne and Geelong. Both cities. The full-power Melbourne FM stations are strong enough in Lorne as well as the Geelong offerings so clearly that’s something.
Any coverage of the Melbourne FM stations in Geelong is fortuitous - ie. It’s lucky. They are not officially licenced to broadcast to Geelong as Geelong isn’t in their official licence area. Don’t know how else to explain it. It’s also called “overspill”. Overspill can sometimes not easily be avoided
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Okay, for those that don’t understand, Licence areas, coverage areas (main or fortuitous) & possible reception areas (local or distance), I’ll give a bit of a run down.
Licence areas be it AM/FM/DAB+ or TV are mapped out, hard bordered areas under ACMA rules where a broadcaster is “licenced” to broadcast into/cover. In most cases, especially around Metro areas, the radio & TV licence areas will differ, sometimes by great distances, so you can’t compare both for reception coverage or expect there to be a radio repeater/translator or even reception in the same areas as TV.
With AM/FM the transmitter powers & coverage are planned/designed that a receiver on that hard licence area border, will get a good enough signal strength to receive any station licenced in that LAP (Licence Area Plan), this will always result in signals going over that border into neighbouring LAP’s, in some locations at quite high signal strengths, this is called fortuitous reception as the planned/licenced signal is not supposed to be strong enough to reliably service these areas, like it is in the main coverage/licence area.
TV is much the same setup, but more often with TV than AM/FM, you’ll have lower powered (than the main site) translators or infill transmitters located closer to the licence area borders.
DAB+ was originally deliberately designed, due to the perfect of none nature of it, that reception wouldn’t travel to be of any receivable use, past the hard LAP borders so unlike AM/FM you won’t necessarily have a strong or even any DAB+ signal at the Licence area borders, their main signal falls well back from those borders & all the main DAB+ transmission sites have signal beam down-tilt on them (signal is angled down towards the ground at a distance close to the transmit site, rather than far out closer to the LAP border like in AM/FM), this was done because with AM/FM the further the signal gets the more it deteriorates & people are less likely to listen to a distant (neighbouring LAP) station over a local one, with DAB+ if it was setup like AM/FM, you’d have perfect reception well into or in some cases entirely covering the neighbouring LAP so people would be more likely to listen to the out of area DAB+ stations over any local AM/FM ones or even local DAB+ ones if they actually had any & they were sub-par programming to the neighbouring ones, thus reducing the profitability of the neighbouring LAP stations & risking the ongoing/future operations of them.
As far as using Melbourne/Geelong for an example, Geelong is part of the Melbourne DTV LAP (Licence area) so it has a local translator in it & you can get Melbourne TV channels there.
Geelong is not part of the Melbourne Radio LAP however, so any Melbourne radio stations you can receive there are as has been said, fortuitous/lucky, none are planned to get into Geelong, but because Mt Dandenong is so high & on the North East side of Melbourne the Melbourne FM signals are directed towards the Melbourne CBD, but then what’s between there & Geelong, nothing but a flat unobstructed water path, so the signals easily travel over that & into Geelong of a good enough signal strength to receive them like a local one.
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Agree, they have tried to null the Melbourne commercial FMs towards Geelong by a restricting power in that direction to 16kw instead of the usual 56kw, but it doesn’t seem to have made much difference because of the elevation of Mt Dandenong and the flat terrain/ water path in that direction as you said.
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