Photo by Brock Wegner on Unsplash
A recent Radio World article summarizes a U.S. Senate Commerce Committee report raising concerns about the removal of AM radio from new vehicles. The report highlights AM radio’s role in national emergency alert systems and notes its low cost to manufacturers. It recommends Congress consider legislation to ensure AM capability remains standard in future vehicles.
DAB/DAB+ has such poor range in metropolitan areas and lossy codecs with frequent stream buffering and dropouts. Even modest hills cause total blockout of DAB signals. DAB really is Dead And Buried – even before it was conceived.
AM is reliable in all conditions and has much greater range, especially at night. The SNR can vary with AM but at least you can hear something unlike DAB which drops dead in true cliff effect fashion.
Ain’t modern technology grand – nope, only to the simpletons who don’t realize it’s really just a house of cards.
The coverage area is determined by the transmitter output power, the gain of the antenna and the losses in the feed system. Terrain will absorbs signals at the higher frequency end.
The Low Frequency (LW) transmitters usually are of huge power and most broadcasters are interested inn ground wave coverage. Sky wave coverage up to 30 MHz cannot be relied upon unless you are a broadcaster in the high frequency bands who have to to match their schedules, paths and the ionosphere. Once you reach the VHF band which includes the FM band, it is line of sight with some temporary atmospheric effects which will extend range. To overcome this a typical FM or DAB+ transmitter is mounted high on a TV transmitter tower. I live 32 km from a pair of 50 kW effective radiated power transmitters with their antenna 180 metres up the mast on top of a hill. I have no problems with drop outs. The current Irish trial is between 8 – 20 kW. https://www.radioworld.com/global/dab-to-be-tested-in-ireland-this-spring shows the coverage area.
We also have low repeaters which receive the parent transmitter off air, boost the power and retransmit a slightly delayed identical signal.. Since DAB+ transmits its data in bursts, the parent will be ignored by the receiver if it is within the coverage area of the repeater.
Please do not confuse DAB and DAB+ DAB+ has a much superior error correction system which works on worse signals and receivers mute if the errors are extended in duration. By comparison DAB sounds like bubbling mud. DAB+’s HE AAC V2 sound compression is more than twice as efficient so we have 18 or more different programs on a single DAB+ transmitter.in stereo.
You obviously hanker for frequencies below 30 MHz, Digital Radio Mondiale has digitised all bands from 153 kHz – 230 MHz and as added clear, stereo sound free of interference, distortion and noise.
World DAB Last update: 24.04.2025 – older versions
Ireland’s spectrum regulator Comreg has commissioned FáilteDAB to carry out a new high-powered DAB+ trial in Dublin and surrounding areas for 12 months. The test which launched in April 2025, is operated by Foothold Communications, which owns and operates transmission towers around Ireland and currently has over 1000 radio link and broadcast systems under management. The trial has also been supported by content regulator Coimisiún na Meán.
On 24 April 2025, industry news portal Radio Today reported that “twenty radio services are now available on DAB+ in Ireland following the launch of FáilteDAB. The latest DAB+ trial across the broader Leinster area includes ten services by Onic, along with services such as Nova Xtra, Classic Hits 80s and 8Radio. There are 19 music stations and one speech service, with Newstalk simulcasting its service on the digital platform. It can be heard in Dublin, Meath, Wicklow, Kildare, Westmeath, Longford, Laois and Wexford.”
Until 31 March 2021, national public broadcaster RTÉ operated a full-service Multiplex across a five transmitter network covering 52% of the population in the main cities.
UK-based small-scale DAB solution specialists Viamux ran a small scale DAB+ trial, in Cork, until August 2019.
Considering that broadcasts are only trials there is no commitment to permanent broadcasts so I am not surprised. This is not the case in other countries.
For an improvement on analog Emergency Alerts see the link below.
https://www.worlddab.org/system/news/documents/000/014/411/original/PRESS_RELEASE_World_premiere_of_DAB__Automatic_Safety_Alert_%28ASA%29_system.pdf?1724143763
It’s unfortunate that there are millions of people who are unaware that the internet is so fragile that if it failed, they might have no access to emergency information. I’ve listened to AM radio since the 1950’s, and it’s still a viable medium for getting emergency information to the public at no charge. At night I can listen to AM stations hundreds of miles away. During a power failure, people without a battery powered radio have used their car radio for information.
Here in Ireland ( EI land to us radio amateurs ) RTE has demolished three important AM masts in recent months ; the long wave mast in Co.Meath , and the medium wave masts in Tullamore and Cork city. They spent too long experimenting with DAB ( Dead And Buried for now ) and are more interested in promoting their digital toys. Soon they will be celebrating the 100th anniversary of the setting up of 2RN , the first official station in the Republic . Advertising on RTE and commercial stations is rapidly dropping so I do not see any expansion of sound radio here for years to come .
Thank goodness for satellite radio !
Des Walsh