Tag Archives: DRM

DRM30 on a Smartphone: KTWR Shows Us The Way

Image via the KTWR Blog

Many thanks to SWLing Post contributor, Dan Van Hoy, who writes:

[Regarding the reception of DRM via smart phone,] I happened to find this KTWR Guam post about decoding DRM30 with a smart phone, app, and an RTL-SDR:

Convert Smart Phone to DRM 30 HF receiver!

We are pleased to report successful use of an SDR Dongle used to directly receive and Decode DRM 30 over HF today.

The SDR Dongle is an RTLSDR v3 type connected to an android smartphone using an OTG cable (phone or tablet must be OTG capable).

The Software used:
1. Android driver (free)
2. DRM+SDR Android App ($4.99)

The Frequency of the HF broadcast is directly assigned within the DRM+ SDR app with two settings
1. Frequency in Hertz
2. RF Gain (0-512)

Demonstration video showing Clean DRM decode of AAC Audio and Journaline data along with live metadata.  (our signal was very strong, so only a short wire used for Antenna, DX’rs will need an appropriate Antenna)

Now anyone with a smartphone and a $20 SDR can receive DRM 30 HF broadcasts…

Click here to read this post on the KTWR blog.

Spread the radio love

An app to decode DRM?

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

Many thanks to SWLing Post contributor, Richard Langley, who shares this story by Hans Johnson at Radio World:

Can an App Solve the DRM Receiver Problem? (Radio World)

The Digital Radio Mondiale standard for digital broadcasting in long, medium, and shortwave bands offers the possibility to transmit audio, text and pictures.

A few broadcasters use DRM for both domestic and international transmissions. DRM’s largest problem is lack of receivers, especially affordable standalone ones.

Some listeners use an SDR, computer and free Dream software to receive the DRM signals, but this audience doesn’t make up the mass audience that broadcasters are looking for.

[…]AlgorKorea didn’t develop the apps with the intention of solving the DRM receiver issue. They developed them to resolve a problem with FM hearing aids used in classrooms.

So how do they work? The DRM+SDR version couples the popular and inexpensive RTL-SDR to an Android device with a USB OTG adapter.[…]

Click here to read the full article at Radio World.

 

Spread the radio love

Tim Whittaker explains route from proof of concept to development of low-cost DRM receiver

Many thanks to SWLing Post contributor, Ed, who writes:

Here’s some new news about low-cost DRM receiver advancement, and links to an audio presentation explaining the route from proof of concept to development of a low-cost prototype DRM receiver by Cambridge Development. SWLing Post readers might find it interesting:

(Source: DRM Consortium)

16 Jan Low-cost DRM Receiver Advancement

DRM member Cambridge Consultants recently announced an under 10 USD prototype DRM receiver, which was reported in our Newsletter and widely in the industry press. The prototype receiver was unveiled during an Innovation Day at their offices in the UK. Neale Bateman, Encompass Digital Media and a member of the DRM Steering Board, attended the event and spoke to company representative, Tim Whittaker, to find out why the interest in producing this type of DRM receiver. Listen here

Tim also explained the route from proof of concept to development that has helped Cambridge Consultants to produce this low-cost prototype DRM receiver.  Listen here

Spread the radio love

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!”

Spread the radio love

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.

Spread the radio love

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?


Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

Spread the radio love

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.

Spread the radio love