Author Archives: Thomas

Stefano invites you to experiment with DRM (Digital Radio Mondiale) over IP

Many thanks to SWLing Post contributor, Stefano Mollo (VK6WFM), who writes:

I have been lately experimenting with DRM 30, with the aim of coming up with a cheap solution to get on air for next to no $$$, for small, local broadcasters that would either go pirate on FM or would not go at all due to the impossibility here in Australia to get a proper FM license at a cost that does not involves selling a kidney (or two)!

I am a ham radio operator, so I turned my attention to DRM30; [the DRM application] DReaM has the capability of acting as a transmitter as well, so I started experimenting.

Click here to download DReaM via SourceForge.

I was very successful at transmitting a DRM30 / 10 kHz signal with a $ 0.50 TX module otherwise intended to transmit data with an Arduino. The signal was received with an SDR + HDSDR + Virtual Audio Cable + DReaM in reception mode.

So far, so good; with this experiment I realised that DRM 30 can, in fact, yield excellent quality at ANY frequency (as I used the 433Mhz LIPD range in my experiment) or better said, with any medium, as long as it is linear enough to transport the DRM signal.

I wanted to find a way to show the World – literally – what can be achieved with DReaM in TX mode…for free!!!

So, after some trial and error, I have set up the system below which allows anyone in the World to “tune in” my “DRM30 radio station” and listen to my DRM30/18 kHz signal, in full blown stereo. Quality is exceptional, and just imagine to send DReaM’s signal to a proper transmitter instead of streaming it over the internet ….

So…point your VLC Media Player (on Windows) to stream from:

…then pipe VLC’s output to DReaM’s input via Audio Cable (or any other Virtual Audio Cable you like).

In DReaM, select the audio cable output as the sound card’s signal input device:

Then select L+R as Channel:

Set the sample rate to the highest value:

One more thing you need to set is the “Channel Estimation: Time Interpolation” parameter to Linear; this is very important!

After few seconds you should be able my test signal, in full stereo, streamed from a PC running DReaM in TX mode, whose output is then captured by MB Recaster and streamed to an ICE Cast server I have in the Cloud. Note that no particular configuration was needed on the ICE Cast server, at all.

This is an example of what can be achieved on a solid transmission channel with DRM30 and only 18 kHz bandwidth (i.e. the normal bandwidth of an AM channel).

One can achieve the same exact audio quality using any channel linear enough to transport an 18 kHz wide DRM30 signal. It doesn’t matter the frequency, or the physical medium per se.

[…]My aim with this experiment is not to send DRM over IP; there are much simpler ways or streaming audio over IP.

Rather, my aim is to demonstrate what can be achieved with 18 kHz +DRM30 on any frequency and on any medium (which, could be for example the electrical distribution overhead lines …. just saying …. 🙂 ).

If only the local regulator would support this, instead of enforcing draconian regulations … such as the restriction of just 6 kHz on shortwave.

Please share your thoughts.

Fascinating experiment, Stefano! Thanks for sharing!

Post readers: If you’re in the mood to do a little experiment, let us know if you’re able to decode Stefano’s 18 kHz DRM30 broadcast over IP! Please comment!

Tommy (N1SPY) on monitoring airplane communications

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Many thanks to SWLing Post contributor, Ivan (NO2CW), who writes:

If anyone is interested in monitoring aircraft communications across HF, VHF and UHF, Thomas, N1SPY put together a demo video of what you can hear and how:

Click here to view on YouTube.

Brilliant instructional video, Tommy! Like you, I love both radio and aviation so appreciate the effort you put behind this video. Great primer!

Click here to check out other projects by N1SPY.

Woofferton Transmitting Station: 75 years of continuous operation

Radio Romania International Listener’s Day 2018

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(Source: Radio Romania International via David Iurescia)

Dear friends, on Sunday, November 4th 2018 we invite you to Listener’s Day on Radio Romania International, to tell us about the role of radio in your life

On November 1st, 2018, we celebrate the 90th anniversary of the first official radio broadcast in Romania. We are celebrating 90 years of documenting history, when radio professionals have kept the public informed, reflecting every stage of events as they occurred, from the interwar period, World War II, the post-war period, as well as the decades of communism and Cold War.

It documented the December 1989 spectacular collapse of the communist regime, then the transition to democracy in Romania. Since then, listening to the radio in itself has changed dramatically, going from the vacuum tube wireless receiver of your grandparents to radio received on a smart-phone or a smart speaker.

Radio Romania International is the voice that has been telling the story of Romania and explained events as they occurred. This year, on Listener’s Day, we would like you to share with us and all our listeners what the role of radio is in your life, and what RRI means to you.

We will be including in our programs a selection of your answers. You can send them by e-mail at [email protected], on Facebook, or using the dedicated form on our website, www.rri.ro.

Click here to view at Radio Romania International.

1917: First wireless transmission from New Zealand to London

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(Source: New Zealand History via Andrea Borgnino)

First trans-global radio transmission to London

From the family sheep station in Shag Valley, East Otago, amateur radio operator Frank Bell sent a groundbreaking Morse code transmission received and replied to by London-based amateur operator Cecil Goyder.

Frank and his older sister Brenda were radio pioneers. Invalided home from the Western Front in 1917, Frank revived a boyhood interest in wireless communication while recuperating. He helped pioneer the use of short radio waves to communicate over long distances, initially through Morse-code telegraphy. He achieved a number of firsts, including New Zealand’s first overseas two-way radio contact with Australia and North America. But it was his radio conversation with London that made world headlines.

When Frank turned his attention to running the family farm, his sister Brenda took over the wireless station, becoming New Zealand’s first female amateur radio operator. In 1927 she was the first New Zealander to contact South Africa by radio. After the Second World War, Brenda Bell moved into professional radio as a writer and broadcaster for Dunedin station 4YA.

Click here to view this article and a photo of Frank Bell at New Zealand History.

Pirate Radio: FCC Enforcement focuses on small markets

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(Source: Tom Taylor Now)

The FCC’s busting more pirates in smaller markets.

True, the Dallas office issues two Notices of Unlicensed Operation for an 87.9 in Houston, run out of New Beginnings Fellowship Church. But agents from Dallas also found a pirate FM at 93.5 up in the smallish Texas Panhandle town of Amarillo. (That one was also operated out of a church, the Iglesia Bautista Renovacion Ministerio Internacional.) The spectrum cops from Dallas also detected a 95.9 in Port Arthur, Texas. And out in California, agents from the L.A. office ventured up to Oxnard to respond to a complaint about a 99.1 operating from a business. (It was a business run by Maria Gonzalez, who gets the NOUO.) So while the traditional pirate radio hotbeds in South Florida, the New York City area and Boston get attention, there seem to be more complaints and more investigations in smaller markets. If the “PIRATE Act” that passed the House ever makes it through the Senate and is signed into law, the FCC would be required to make twice-yearly sweeps of the five most active areas for pirates. But it seems illegal FMs may simply be popping up in less-likely places. The equipment’s cheap and you might not get caught. Though one pirate in Miami got nabbed doing something novel – operating a pirate station out of a parked RV. (Sure keeps the costs down.)

Click here to read at Tom Taylor Now.

The “Tecsun Radios Australia Q-3061” DRM Shortwave Radio

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Many thanks to SWLing Post contributor, Alan Hughes, who notes that Tecsun Radios Australia have announced a new DRM stand-alone receiver: the Q-3061.

When I first received Alan’s tip, I was surprised that I had not been been given some advance notice or even a hint about Tecsun developing and producing a DRM radio. Then I saw the Q-3061 product image and it looked to be a spitting image of the Gospell GR-216 DRM radio. A quick look at the radio’s back panel and the connection with the GR-216 was confirmed.

Reading through the product description, it appears they worked with Gospell to badge this for Tecsun Radios Australia’s primary markets:

“The Tecsun Radios Australia Q-3061 DRM Shortwave Radio is for experienced shortwave users. There a limited number of DRM signals available in our region although the total number of DRM broadcasts are increasing. This radio is squarely aimed at radio enthusiasts and DXers, most signals require an external antenna, experience, and patience. We recommend our Tecsun Radios Australia Q-3061 DRM Shortwave Radio be used in conjunction with our Tecsun Shortwave and AM Outdoor Antenna for the best results (this is the setup we have in our Brookvale NSW office).

The Tecsun Radios Australia Q-3061 DRM Shortwave Radio is the culmination of several years work. Tecsun Radios Australia has worked in close co-operation with the manufacturer providing testing results from locations across the Pacific, including Samoa, Vanuatu, Solomon Islands, Fiji, and New Zealand. Reception of DRM signals in Australia requires many factors to be optimised, because we are outside the traditional coverage area of most broadcasters. Nevertheless, with an optimised antenna, correct selection of DRM broadcaster, schedule and good propagation conditions DRM signals can be received. New DRM broadcasters are appearing every month.”

After the product description they also include this disclaimer: