Category Archives: Digital Modes

Final step for proposed rule to allow AM broadcasters to use all-digital transmissions

Many thanks to SWLing Post contributor, Paul Evans, who notes:

The Federal Register has today published the proposed rule for AM stations to go digital. This is close to the final step.

https://www.federalregister.gov/documents/2020/01/07/2019-27609/all-digital-am-broadcasting-revitalization-of-the-am-radio-service

Comments before 2020-03-09, replies by 2020-04-06.

Thanks for the tip, Paul!

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KiwiSDR update brings integrated DRM reception!

Many thanks to SWLing Post contributor, Mark Fahey, who shares the following tweet from KiwiSDR:

“Happy Holidays. Software update brings integrated DRM receiver (Digital Radio Mondiale) based on Dream 2.1.1 to all KiwiSDRs. Stock BeagleBone-Green/Black based Kiwis support one DRM channel, BeagleBone-AI Kiwis support four. Development work continues.”

Ironically, I had only recently published a post asking if anyone had ever attempted to decode DRM using a KiwiSDR. Turns out, several readers had by porting the IQ audio output into the DREAM application. Now that KiwiSDR will have a native DRM mode, this will no longer be necessary.

Many thanks, Mark, for sharing this tip! As you say, this is “mega news!”

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Cambridge Consultants design a prototype $10 DRM receiver

DRM broadcast (left) as seen via a KiwiSDR spectrum display.

Many thanks to SWLing Post contributor, Michael Bird, who shares the following news via Cambridge Consultants:

Digital launched, ever so long ago, with TV and radio. So what’s the big story? It’s that the last piece of the digital jigsaw is finally in place: a system called Digital Radio Mondiale (DRM), designed to deliver FM-radio-like quality using the medium wave and short wave bands.

We’re familiar with AM on medium wave and accustomed to the horrible buzz, splat, fade away and back again. But it does have a great advantage in that it will reach for hundreds of miles from a single transmitter. That’s a lot easier than FM or DAB, which both need transmitters every 30 or 40 miles. No fewer than 443 DAB transmitter sites are needed to cover the UK alone.

So take a modern digital scheme, apply some clever (and low cost) computing power, and you can get good sound for hundreds of miles. You get to choose radio stations by name instead of kilohertz, and you can even receive text and pictures. Emergency warning and information features are also built into DRM.

Great technology. But will it fly? Is it available for everyone?

The new news is that India, through its national broadcaster All India Radio, has invested in and rolled out a national DRM service, live today. Just 35 transmitters cover that large country. New cars in India have DRM radios in them now. Other countries like South Africa, Malaysia and Brazil are likely to follow India’s lead.

But something’s missing. The radios that can receive DRM are still prohibitively expensive, especially for those markets that would benefit most. So vast swathes of the world remain unconnected to the services that DRM can provide. Where’s the cheap portable that you can pick up from a supermarket to listen to the news or sport?

Cambridge Consultants has just held its annual Innovation Day, where we throw open our doors to industry leaders and reveal future technology. One of our highlights was the prototype of a DRM design that will cost ten dollars or less to produce, addressing that vital need for information by the 60-ish per cent of our global population that doesn’t have internet or TV. It’s low power, so can run from solar or wind-up.

This design will be ready in 2020, available for any radio manufacturer to licence and incorporate into its own products. We’re doing our bit to make affordable radios for every corner of the globe!

Click here to read this post at the Cambridge Consultants website.

Michael also shares this piece from Radio World regarding this project.

I must admit: there have been so many proposed low-cost DRM receiver designs that never came to fruition, it’s easy to be skeptical. I assume the $10/9 Euro design will be for the receiver chip only–not the full portable radio, of course. They plan to bring this to fruition in 2020, so we’ll soon know if they succeed.

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Ongoing DRM tests in Hungary: Could DRM be decoded via a KiwiSDR–?

Budapest, Hungary (Photo by @DNovac)

Several readers have written recently asking about the DRM tests we mentioned in a previous post. These tests are being sponsored by the Budapest University of Technology from June 1, 2019 to May 31, 2020–thus, they’ve been on the air for several months already. 

The programming, which was produced by Radio Maria, is being played in a loop–repeated over and over again. The signal is a modest 100 watts and is being transmitted via a 5/8 wavelength vertical on 26,060 kHz.

This is a low-power DRM broadcast using a very modest antenna, so I suppose it goes without saying that expectations should be in check. It’s a very long-shot for those of us living outside of Europe, of course. With that said, there are a number of KiwiSDR sites nearby Budapest:

You could certainly see the distinctive DRM signal on a KiwiSDR waterfall display, but I’m not sure how you’d decode it.

KiwiSDRs do have an IQ mode, however. I am very curious if anyone has ever used a KiwiSDR to decode DRM, perhaps, using Dream? Could the KiwiSDR IQ be fed into DREAM with a virtual audio cable?

Please comment–have you ever decoded DRM via a KiwiSDR site?


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Hungary conducts low-power DRM tests

Budapest, Hungary (Photo by @DNovac)

(Source: Radio World via Michael Bird)

BUDAPEST, Hungary — Digital Radio Mondiale transmissions began from Budapest, Hungary, last June. Although two Hungarian broadcasters previously tested DRM on medium wave, the transmissions are the country’s first DRM trials on shortwave.

The Department of Broadcast Info-Communications and Electronic Theory at the Budapest University of Technology is conducting these latest trials. Csaba Szombathy, head of the broadcasting laboratory, is also head of the project, which will last for at least 12 months.

While the 11-meter 26,060 kHz frequency is well known for use in local broadcasting, it’s rarely implemented for international broadcasting. […] Researchers have also performed tests in this frequency to measure coverage and determine optimal mode and bandwidth on various occasions in Mexico and Brazil. The new Hungarian trials will add to this research.

Szombathy initially operated the transmitter with just 10 W of power into a 5/8-inch vertical monopole. Radio Maria, a Catholic station, is providing a 25-hour program loop, while a Dream DRM software-based encoder broadcasts the signal using AAC encoding. In spite of the low power, the program was reportedly received in the Netherlands.

In early September, Szombathy moved the antenna and transmitter to a slightly different location to improve coverage. He increased the power to 100 W.[…]

Click here to read the full article at Radio World.

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EU vehicle digital radio legislation

Photo by Philipp Katzenberger

Many thanks to SWLing Post contributor, Mangosman, who shares the following:

The European Union as asking its member states to legislate the following, which Germany has just done today.

EU Vehicle Directive

This directive requires all new car radios sold in the European Union to be capable of receiving digital terrestrial radio, in addition to any FM or AM functionality which manufacturers may want to include. The code also grants EU member states the power to introduce rules requiring consumer radios to include digital capability.

Following its adoption by the European Council, the directive was published in the Official Journal of the European Union (OJEU) and came into force on Dec 20 last year. For the automotive industry, the key section of the European Electronic Communications Code is Article 113, XI:

“Any car radio receiver integrated in a new vehicle of category M which is made available on the market for sale or rent in the Union from … [two years after the date of entry into force of this Directive] shall comprise a receiver capable of receiving and reproducing at least radio services provided via digital terrestrial radio broadcasting. Receivers which are in accordance with harmonized standards the references of which have been published in the Official Journal of the European Union or with parts thereof shall be considered to comply with that requirement covered by those standards or parts thereof.”

The policy commences 21st December 2020 and applies to any vehicle with 4 or more wheels. It does not apply to amateur radio equipment. The radio must be able to display the broadcasters’ name.

Note the way the type of receiver is phrased is digital terrestrial radio, it does not specify what type. It obviously applies to DAB+ because there are many DAB+ transmitters in Europe, but could also apply to DRM. With the advent of Software defined receivers, it is easy to have both standards. This would then open they way for high frequency (short wave) DRM in most vehicle radios. Remember that there are now 1.5 million factory installed DRM car radios in India which has been achieved in 18 months.

This decision will open the way for all new radios to include DAB+/DRM in all markets except the USA/Mexico.

Thank you for sharing this!

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FCC to consider allowing AM broadcasters to transition to digital

(Source: Radio World)

All-Digital on the AM Band? The FCC Might Allow It Soon

AM radio station operators in the United States may soon have the option of switching their transmissions to all-digital.

It’s not a done deal; but the concept is about to take a step closer to reality, because the Federal Communications Commission will consider a proposal at its next meeting that would start a process. It will take comments on whether to allow AM band licensees to make the switch if they want.

Ben Downs, VP/GM of Bryan Broadcasting in Texas, petitioned the FCC in March to initiate a proceeding to authorize the all-digital mode of HD Radio.

Allowing stations to use all-digital transmission is an idea that some broadcasters feel could give business-challenged AM stations in the United States new life or at least another option. Turning off their analog signals would mean that most existing receivers could no longer pick up that signal; but many AM broadcasters are currently heard on FM translator simulcasts now. And adding the all-digital AM option could open up new possibilities for them as the number of digital receivers in the marketplace continues to grow.

[…]Chairman Ajit Pai described the proposal in a blog post Monday: “Just as the FCC is trying to keep pace with changes in the market, so are AM radio operators, and the commission wants to give them as much flexibility as possible to compete in the digital age,” Pai wrote.[…]

Read the full article at Radio World.

Click here to read the proposal (PDF) that will be discussed at the November FCC meeting.

The Radio World article mentions WWFD in Frederick, MD–a station that has been broadcasting AM digital for over a year. We posted a note about this last year and I even included a short recording/video with reception when traveling through the area.

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