Reaction to Radio Australia's planned shortwave closure

Saturday, December 17, 2016
Image credit: Matt Kieffer
Further to my previous post on the planned closure of Radio Australia's shortwave transmissions, below are some of the reactions I subsequently came across in the Australian and Pacific media. There is now also a petition on calling on the Australian government to cancel the decision, which I encourage all Radio Australia's supporters to sign.

ABC managing director Michelle Guthrie is facing conflict on a new front after two Labor MPs demanded the national broadcaster reverse a decision over the future of broadcasting in the Northern Territory.

Senator Malarndirri McCarthy and member for Lingiari Warren Snowdon have expressed "deep disappointment" and concern about the plan to end shortwave broadcasting in the NT from the end of January.


The ABC is continuing to broadcast via FM and AM frequencies, the viewer access satellite television (VAST) service and online streaming but various NT figures have argued the shortwave transmitters - in Katherine, Tennant Creek and Roe Creek - allow remote listeners to access radio and are a crucial platform during natural disasters.

A group of Indigenous rangers told the ABC last week that ending the shortwave service could be life-threatening because, when operating remotely, the service is the "only way of getting the weather reports" that can warn of incoming cyclones.


Their intervention comes as Ms Guthrie marks an intense first year in the job, with staff at Radio National recently passing a no confidence motion in management.
Australia's opposition is asking the ABC questions about its decision to shut down its shortwave service to the Pacific.

Labor's spokesperson on International Development and the Pacific, Senator Claire Moore, says they are concerned that Australia's engagement in the Pacific will suffer because of the decision.

She was recently in the Pacific as part of a bipartisan delegation of Australian politicians visiting Vanuatu, Solomon islands and Samoa.

Ms Moore tells Bruce Hill Labor has concerns about what happens with radio broadcasting during cyclones, and whether other countries might want to fill the gap left by Australia withdrawing.
[...] The move away from shortwave to FM transmissions and digital and mobile services has been accelerated despite the fact that FM frequencies can easily be shut down by disaffected political leaders, as happened in Fiji in 2009 on the order of then self-appointed Prime Minister Frank Bainimarama.

It was a matter of national pride at the time for the ABC to be providing independent information for Fijians via shortwave, with then managing director of the corporation, Mark Scott, highlighting a text message sent from inside Fiji to the ABC, which read “We are trying to listen to you online but are having difficulty. Please keep broadcasting. You are all we have”.

Shortwave radio has played a valuable role in getting information to communities in the middle of civil disturbance, such as in East Timor in the lead up to independence.

In Burma, it was internal leaders who sought the shortwave services. In 2009, Burmese pro-democracy leader Aung San Suu Kyi called on Australia to provide shortwave broadcasts. At the time the ABC’s director of international, Murray Green, said the move reflected the ABC’s ongoing commitment to serving people in those parts of Asia and the Pacific who live without press freedom. Even before this announcement was made, the price of shortwave radios was increased in Burma’s Sittwe market.


[The] BBC clearly recognises a need to boost its international broadcasting, using shortwave to beat censors in autocratic regimes.

It is a great shame for the Pacific that Australia no longer agrees.

"As Pacific nations are going through the usual cyclone cyclone, its just such a shame that they will lose a key, credible information source to rely on,” says Miller.

“It's clear that no thought was given to the link between disaster communications and this service, or even the fact that FM is largely unreliable in bad weather and only available in urban areas."

"It's a slap in the face for the millions who've connected to Australia and to regional news through this service, because they are unlikely to be the ones targeted in the new digital content offerings being touted by ABC."
A decision by the ABC to halt shortwave broadcasts early next year has been criticised by a former manager of Radio Australia.

The shortwave transmissions to Asia and the Pacific will cease from January 31st next year, as alternatives such as FM and Internet become more prevalent.

Former head of Radio Australia and subsequently a consultant on international broadcasting in the Pacific, Jean Gabriel Manguy, tells Bruce Hill the decision is short sighted.


Shortwave gems part 5

Saturday, December 10, 2016
Below are a few more interesting shortwave clips from my archives. Many thanks to Gordon VK2UB for the tune identifications, which you can find in the comments section.

A tune recorded outdoors from Radio Joey, a pirate radio station supposedly run by a 14 year old DJ from the Netherlands.

Persian Jazz fusion from Radio Farda, recorded outdoors.

A Japanese war-time song from NHK Radio, recorded outdoors.

Hypnotic carnatic classical vocal music from All India Radio, recorded indoors.


Radio Australia to shut down shortwave transmissions

Tuesday, December 06, 2016

According to the press release on the ABC website:
The ABC will end its shortwave transmission service in the Northern Territory and to international audiences from 31 January 2017. 
The move is in line with the national broadcaster’s commitment to dispense with outdated technology and to expand its digital content offerings including DAB+ digital radio, online and mobile services, together with FM services for international audiences.
This is sad news and I can see a lot of complacency in this decision. To paraphrase the post I wrote when Radio Australia had a temporary outage earlier this year, depriving people in the less advantaged territories of the ability to receive global broadcasts at no cost results in a less equal world. A good friend of mine from India who went on to become a highly successful academic in the USA attributed his career path to regularly listening to the BBC World Service and Voice of America on shortwave while growing up in a poor neighbourhood. True, India is now much better connected than it was back then, but in how many other regions will shutting down shortwave radio result in lost opportunities for the people there to connect with the rest of the world? We wouldn’t dream of cutting Internet access in poor neighbourhoods in our own countries; shutting down all libraries in less privileged parts of our cities would result in an outcry. It’s sad to see that many governments around the world no longer feel that they have this responsibility beyond their own borders.

It is particularly tragic because Australia's case is one of the few in which using shortwave is well justified both in terms of the underlying technology and the geography of the region. From a number of my conversations online I have gathered that many people use shortwave to listen to RA in the Pacific and quite a few more in the large swaths of rural Australia itself. Australia is a regional economic powerhouse, with which many smaller neighbouring nations have deep material and cultural links; many of these countries have little or no Internet or FM infrastructure to speak of.

On a personal note, I will miss hearing Radio Australia over the ether. Despite Europe being well outside their target area, their signals have always been very strong and clear, and the programming amongst the best out there — both on shortwave and elsewhere.


Shortwave gems part 4

Saturday, December 03, 2016
In this post I upload a few melodic audio clips extracted from an outdoor shortwave spectrum grab made on April 15th, 2015. The nice surprise about these recordings is that I managed to recover the spectrum file containing them, which I thought was corrupted and not playable beyond the short snippets I included in my original post. I used Audacity to repair the file, and now the remainder of it — some two extra hours — play flawlessly. Being able to hear this capture in its entirety for the first time in 18 months feels like time travel. I'm especially pleased about this recovery as the recording contains a station that is no longer on shortwave: Zimbabwe's Radio Dialogue.

A song recorded from Radio Dialogue.

A song heard on Voice of America's Somali service.

An interesting fusion of Persian and Spanish music from Radio Farda.

Light music broadcast on DPRK's Voice of Korea.


Shortwave gems part 3

Friday, November 25, 2016

In this post I upload a few interesting shortwave clips from my archives, made using my indoor recording set-up.

A Romanian folk song recorded from Antena Satelor's long wave transmission.

An interesting fusion of western classical music with Arabic vocals recorded from Morocco's Medi1.

A song by Wadih El Safi recorded from Radio Damascus's medium wave transmission.

A qawwali by Nusrat Fateh Ali Khan recorded from All India Radio.

A slow, dreamy song recorded from The Voice of Turkey.


Portable spectrum capture Q&A

Friday, November 18, 2016
The view from one of my portable spectrum capture DXing spots in the summer

Since writing my last post on portable shortwave spectrum capture I have received a few questions about my equipment choices. My answers follow below:

Why use the tablet instead of a laptop?

  • Small size: At 8", it is much smaller than almost any laptop available on the market.
  • Price: at $169, it's cheap enough to be the dedicated device for this project. I suspect that many tablets under $100 — such as the HP Stream 7 — are in the same performance league as my two year old Toshiba, making it an even more attractive choice cost-wise. 
  • Battery life: the tablet can capture the spectrum at 3MHz bandwidth for 2.5 hours on a single charge. None of the laptops I own would be able to do the same.
  • USB (5V) charging: this makes it possible to replenish the tablet's battery using a portable power bank, an in-car charger or a foldable solar panel — great for when you want to scan the bands while camping off the grid.

Why use AirSpy / SpyVerter instead of another SDR?

  • Low power consumption: the AirSpy/SpyVerter combination can run entirely off the USB power supplied by the tablet, requiring no additional power supply units.
  • Wideband performance: the two other SDRs I own that can be powered by the tablet alone are the FunCube Dongle Pro+ and SDRPlay RSP1. The FunCube dongle's maximum bandwidth is 192 kHz, while AirSpy is capable of pulling in up to 3MHz without maxing out the tablet's CPU. SDRPlay can provide a similar bandwidth, however, its performance leaves a lot to be desired compared to the other two SDRs. Simply put, the main problem with this radio is the large number of mixing/imaging artefacts at comparable sensitivity (signal to noise ratio) levels and spectrum bandwidth. I demonstrate this in the video below.
  • Bundled software: The other problem with SDRPlay is that the compatible software packages I have tried cannot write large (3MSPS) streams to disk reliably without buffer overruns on my tablet. In my evaluations, the Baseband Recorder plugin for SDR# is quite exceptional in this regard, and of course nowadays SDRPlay is not compatible with SDR#.

Why use a long wire antenna and not an active magnetic loop or a mini-whip?

  • Power consumption:  the long wire dipole requires no additional power, unlike the alternatives.
  • Portability: an active loop antenna would require significant additional space; the same is true for a mini-whip antenna, although to a lesser degree.


Shortwave gems part 2

Tuesday, November 15, 2016

In this post I continue uploading some of the more interesting things I have recently heard on shortwave using both my outdoor and indoor recording setups. Some of these recordings were made using standalone shortwave radios while the others were extracted from my SDR spectrum captures.

A mellow atmospheric tune from Medi1 radio, Morocco. Recorded indoors.

Sudanese light pop music from Radio Tamazuj. Recorded outdoors.

A song recorded from North Korea's domestic radio service, KCBS Pyongyang. The performer makes the surprising move of copying Whitney Houston's vocal style towards the end of the track, something that would probably have been considered too western and decadent in North Korea only a short while ago. Recorded outdoors.

Funky Indian film music from All India Radio, recorded indoors.

Traditional Greek music from the Voice of Greece, recorded indoors.


Simple external antenna attenuation for outdoor SWLing

Saturday, November 12, 2016

I recently purchased a Sony ICF-SW100 after reading multiple glowing reviews of it on eHam and the SWLing post. It's a great little shortwave radio that can easily fit into a jacket pocket. The unit has an external antenna input together with a DX/Local switch that adjusts the radio's sensitivity. However, after using the radio outdoors for several days I have found that the DX setting is just a little too sensitive when using it with the long wire antenna (resulting in distortion on some medium-strength signals), while the Local setting isn't very sensitive at all (meaning that some of these signals can only be heard very faintly).

It turns out that this problem can be solved by using a variable attenuator available in Maplin. The attenuator's specifications state that it has a 2dB — 20dB range and that it operates from 5MHz upwards. However, I have tested it with the ICF-SW100 as well as with my other radios, and I have found that it works very effectively all the way down to long wave. With some additional cable accessories, it's possible to insert the attenuator between ICF-SW100's external antenna input and the long wire as follows:

When I head out in the morning not knowing if I can get any free time later in the day to SWL outdoors, I take the following "opportunistic DXing kit" with me:

That's the Sony ICF-SW100, a Sony ICD-PX333 recorder, the Maplin variable attenuator with all the cable accessories, an audio volume attenuation cable (for connecting the recorder to the radio's line output), and the long wire antenna.

I am quite pleased with ICF-SW100's performance so far, and with this simple and cheap attenuator it's possible to get even more out of this radio in challenging reception conditions.


Portable shortwave spectrum capture for the urban city dweller

Wednesday, November 09, 2016
Capturing the shortwave spectrum out in the field.

Radio interference is a major problem in big cities when it comes to indoor shortwave reception. One effective solution I have found is to head for the local park and engage in scanning the bands there. However, since my time for making such outdoor trips is limited, I would always feel like I am missing out on a lot of radio action by monitoring a single frequency, which is all you can do with a standard shortwave radio. There are so many signals out there — which one should I go for? This inspired me to put together a lightweight, portable set-up that would let me capture large chunks of the shortwave radio spectrum out in the field, which I could later explore in detail. After two years of experimenting with various Software Defined Radio (SDR) technologies I am pleased to report that I finally have a solution that works well for this purpose.

A good SDR can give the user access to large portions of the radio spectrum via a graphical user interface. The user can then either process a specified part of it in realtime or record the chosen spectrum window in its entirety onto disk and analyse it later with the supplied software. Here is a short video showing the playback of one of such spectrum captures I made in a London park in September 2016. Note the final part where I zoom out to show the entire recorded frequency range (covering two broadcast bands with one ham band in the middle!):

When I got home from the park, I was able to replay that part of the spectrum capture many times over while scanning the frequency space, which is how I was able to identify a weak signal from a very distant ham radio operator that I might have otherwise missed.

Below is the list of the components I have used to put together my "portable spectrum capture lab".



1. Toshiba Encore 8" Tablet (Windows 8), 2014 Model ($169)

I bought this tablet in July 2014, based on the following criteria: the device had to have a reasonably powerful Intel processor, running the Windows 8 operating system. I believe that there are currently models on the market that are at least as powerful and are substantially cheaper (<$100).

2. On The Go USB Adapter ($15)

3. AirSpy R2 SDR ($169)

Owing to its unique hardware design, the AirSpy SDR can monitor large parts of the radio spectrum (up to 10 MHz in bandwidth) while offering a high dynamic range and robustness to overloading, with almost no mixing/imaging products.

4. SpyVerter HF UpConverter ($49)

This additional device enables AirSpy to cover the shortwave bands (in fact, the entire frequency range between 0 khz and 30 MHz) and must be connected in-line between the AirSpy's front end and the antenna feed line, as follows:

Connection cables

Below is a small collection of cable accessories to connect the antenna to AirSpy/SpyVerter:

5. 10cm SMA Male to SMA Male Straight RF Coaxial Jumper Pigtail ($2)

6. BNC Male Plug to SMA Female Jack Adapter ($2)

7. BNC Female Coupler ($5)

8. 3m long BNC cable ($15)

Matched dipole antenna

I use a three-terminal matched balun connected two 6 metre copper wires via its antenna terminals as a dipole antenna, and connect it to the SDR via the feed line terminal with the 3m BNC cable listed above. The balun (Wellbrook UMB130) is engineered in a way that prevents the radio noise current from the tablet (usually a significant source of interference) flowing into the receiving part of the antenna.

9. Wellbrook UMB 130 balun ($60)

10. 2 x 6m Copper Wire ($16)


11. Fight Case ($35)

This foam-filled flight case comfortably houses all of the components. The parts 1 to 7 can remain assembled together, reducing the deployment time in the field.

12. Samsung 64G Ultra-High-Speed MicroSD Card ($19)

I use this fast microSD card as the destination for my outdoor SDR recordings. The high transfer speed is critical - using slower microSD cards will result in large portions of the spectrum being dropped from the recordings. 64 Gigabytes can accommodate roughly one hour of spectrum data at 3 MHz bandwidth.

13. FAVI Bluetooth keyboard with trackpad ($37)

Windows tablets suffer from one major drawback: the touchscreen interface is usually inadequate for software that was designed for traditional computers with mice. A portable Bluetooth keyboard with a built-in trackpad solves this problem.

14. Bluetooth Wireless Audio Transmitter & Receiver ($17)

This small gadget turned out to be a very important part of the entire project. The Toshiba tablet has a rather unusual interference quirk that initially caused me hours of frustration. It turns out that significant amounts of radio noise are injected into the SDR when the tablet's external speakers are active. One way to fix this is to plug a pair of headphones into the tablet's line out jack, but this forces the listener to be glued to the device. The alternative is to pair the tablet with a Bluetooth audio receiving unit, such as the one listed above. It is worth noting that my other Windows tablet — a Dell Venue 8 — also suffers from this strange artefact.

Total cost: $610

Internal layout of the flight case

You'll see that I have stacked the SpyVerter enclosure on top of the AirSpy one. As the latter can get very hot, it is essential to leave a sufficiently large gap in the foam for ventilation. It's also worth leaving a small gap next to the tablet's power button to prevent Windows from accidentally going into standby mode.

Software configuration

The best software to use with the AirSpy/SpyVerter combination is SDR#. It offers an impressive collection of features that many software packages and conventional radios don't have, such as advanced noise reduction and synchronous detection with passband tuning. The following adjustments are required to make recording the spectrum a seamless experience:

Install the Baseband Recorder and File Player plugins

Baseband Recorder: this plugin enables efficient recording of very large spectrum (or "baseband") files. Download and decompress the plugin zip file. Copy the .dll files into the directory with the SDRSharp.exe executable. Open the MagicLine.txt file and copy the first line of text into Plugins.xml file, just before the "</sharpPlugins>" line.

File Player: this plugin enables the playback of recordings made with the Baseband Recorder plugin. Download and decompress the plugin zip file. Copy the .dll files into the directory with the SDRSharp.exe executable. Open the MagicLine.txt file and copy the first line of text into FrontEnds.xml file, just before the "</frontendPlugins>" line.

Configure Baseband Recorder

Open SDRSharp.exe and check that the program reports no errors when it loads.

Baseband Recorder configuration

In the plugin pane on the left, expand the Baseband Recorder tab and click "Configure". Change the File Format to WAV RF64 and make sure that the File length limit check box is not ticked. Click "Folder select" and choose the MicroSD card as the destination directory for the recordings.

Adjust AirSpy settings

Disclaimer: in this section I describe how I capture the maximum spectrum bandwidth that my tablet's CPU can handle. It involves operating SDR# in "debug mode" and exposes some internal functionality of AirSpy, which, if used incorrectly, can damage the radio. If you choose to copy my approach, please understand that you are doing so at your own risk and follow my instructions carefully to avoid voiding your AirSpy warranty.

Open SDRSharp.exe.Config file in Notepad. Look for "<add key="airspy.debug" value="0" />" line and change it to value="1".

Once the AirSpy and SpyVerter have been connected to the tablet, open SDR# and select AIRSPY in the Source tab. You will see the following configuration dialog.

AirSpy configuration

In the "Sample rate" field, type in "6 MSPS". For the "Decimation" option, choose "2". This setting will result in spectrum captures of 3 MHz bandwidth (although only 2.4 MHz of it will be shown on the waterfall display). To capture smaller chunks of the spectrum, increase the decimation value. Make sure the SpyVerter check box is ticked. Do not touch any of the fields or buttons under the "Address Value" line.

Make a short test recording

Press the play button in the top left corner and set the desired frequency.

In the Source tab, select the "Linearity" option. Keep increasing the Gain value by one position at a time until you notice that the radio signals suddenly become "saturated" (the waterfall display becomes full of artefacts and the signal you are listening to gets swamped with noise). Take the Gain value back down by two positions. This will ensure high sensitivity while preventing AirSpy from overloading.

In the Baseband Recorder tab, press "Record". While recording, do not change the radio frequency and do not move/drag the waterfall portion of the display. Stop the recording after a few minutes.

SDR# FilePlayer plugin

In the Source tab, change the input to "File Player" in the drop down menu. Click the Settings cogwheel button and select the spectrum recording file from the MicroSD card. A vertical band visualising the timeline of the spectrum capture will appear immediately to the right of the plugin pane. Click on the play button and select a radio signal to demodulate in the spectrum display. Listen to the audio carefully to make sure there are no dropouts or clicks: if so, your tablet and MicroSD card are capable of handing and storing the specified spectrum bandwidth.

Keep an eye on the gain

While making longer spectrum recordings, select a weak radio signal and keep monitoring its audio for signs of overloading. If the overloading does occur, reduce the Gain value further by one or two positions.

Some example spectrum captures

Shortwave for lunch. Playing back parts of the shortwave spectrum captured earlier in the park, inside a local cafe.
Below are some example videos in which I play back and explore the spectrum recordings I made during the trips to my local park.

Tropical and the 49m bands recorded outdoors on 03/07/16 at 0432 UTC. A good time of the day for listening to Latin America on shortwave.

Listening to Radio New Zealand International.

Radio Aparecida from Brazil, usually a challenging catch in Europe.

Questions, suggestions?

Drop me a line in the comments section or hit me up at @LondonShortwave. Also, be sure to check out the portable spectrum capture Q&A post I wrote in response to some of the questions I received.


Shortwave gems part 1

Friday, September 23, 2016
In this post I include some of the more interesting things I have recently heard on shortwave using both my outdoor and indoor recording setups. Some of these recordings were made using standalone shortwave radios while the others were extracted from my SDR spectrum captures.

Very interesting vocal style heard on Ethiopia's Radio Fana. Recorded outdoors.

A British Airways flight bound for Antalya communicating with a ground control station over Stockholm Radio about a disturbance onboard. Recorded outdoors.

More of the traditional Korean clarinet music that is rather unusual for North Korea's shortwave service. Recorded outdoors.

Tajikistan's shortwave service, usually a difficult catch in Western Europe. Recorded outdoors.

Some incredible vocal dexterity from the Moldovan singer, Laura Lavric, heard on Romania's longwave service, Antena Satelor, recorded indoors.

Raï and Hip-Hop fusion on Algeria's Jil FM, received on mediumwave indoors.


Radio Australia shortwave outage

Tuesday, August 16, 2016

Over the past few days, I and many other shortwave listeners have noted that Radio Australia can no longer be heard on the air. Many of those who contacted the broadcaster received a cut-and-paste statement in response, saying that the outage is a result of technical maintenance. The wording is somewhat suspicious, however:
We are currently working with our transmission provider on a number of shut downs over the past week and again over the next week to investigate a range of technical and commercial issues for the service.
(emphasis mine). This reminded me of a comment from one of my blog readers, left in response to our endangered shortwave stations initiative:
rubbersoul1991 on 3 May 2016 at 02:46 
Thanks for the post. The Australian Government is about to hand down its 2016/17 budget tonight and has foreshadowed another round of cuts to the ABC. The new head of the ABC is an ex Google executive [...] so a nuanced response may not be forthcoming. These are dark days for Radio Australia and it may not survive another year.
The budget was passed shortly after the comment was left, but could Radio Australia be quietly testing the waters with ceasing shortwave broadcasts in advance of the next round of possible cuts?

The usual arguments about the economics of running a high-powered shortwave radio service are well known and have been discussed many times over. And time and again, what is missing from these discussions is the humanitarian aspect: depriving people in the less advantaged territories of the ability to receive global broadcasts at no cost results in a less equal world. A good friend of mine from India who went on to become a highly successful academic in the USA attributed his career path to regularly listening to the BBC World Service and Voice of America on shortwave while growing up in a poor neighbourhood. True, India is now much better connected than it was back then, but in how many other regions will shutting down shortwave radio result in lost opportunities for the people there to connect with the rest of the world? We wouldn’t dream of cutting Internet access in poor neighbourhoods in our own countries; shutting down all libraries in less privileged parts of our cities would result in an outcry. I find it hard to believe that this point is lost on the people charged with making such decisions and one can only hope that this is indeed a temporary outage.

Update (17/08/16) from Radio Australia's reception advice:

Update (19/08/16):


A few catches from the indoor spectrum grabs

Saturday, June 18, 2016
I am enjoying using my indoor spectrum capture set-up for recording endangered shortwave stations. The set-up relies on my earlier work on mitigating urban radio interference, caused by being in a busy apartment building in London:
I thought I'd share a few of the catches I have made so far. First up, some good music. Here's an atmospheric set from the Voice of Greece on April 21st, 2016 at 2340 UTC:

A beautiful set of qawwalis and ragas from All India Radio Urdu service, recorded on May 23rd, 2016 at 0055 UTC. I especially like the song at 5 minutes 30 seconds into the recording:

I have also been fortunate to catch some more distant transmissions, such as Radio Thailand on 13/06/2016 at 1900 UTC:

A nice bonus that I didn't expect to show up in the spectrum recordings was the Voice of Turkey's English language broadcast on 04/06/2016 at 0300 UTC:

Finally, propagation from Cuba hasn't been great lately and I certainly have much clearer recordings of it from indoors than the one below, but the SDR# software did a fine job of pulling it out from the noise:

Overall, this has been a fun little project and given that I can make these recordings regularly (unlike the trips to my local park), there is a steady stream of gems to be extracted from the radio static and explored.


Morse code transmission over the Voice of Turkey's signal

Thursday, June 16, 2016
I have been regularly recording the small spectrum window containing the endangered stations I mentioned in one of my previous posts. Three days ago I noticed something strange: a morse code transmission superimposed onto the Voice of Turkey's signal on 9460 kHz (video below):

Using SDR# I extracted the coded signal while suppressing the rest of the audio (recording embedded in the player below):

My Morse knowledge is patchy to say the least, so I decoded it using Fldigi. At the start of the recording, the sequence "8T1" is repeated a dozen of times. I Googled around and found another YouTube video of a Morse code transmission from a numbers station, reportedly codenamed M01, which also had multiple repetitions of "8T1".

Numbers stations are still sending messages from many different corners of the world. However, if I indeed captured an M01 transmission in this instance, what makes it unusual is that it was embedded inside a signal from a broadcast station and that it was strong enough to be heard clearly. I'll watch out for further occurrences of M01 on the airwaves.

Update: I received the following pointer from @priyom_org:
While the station supposedly operates daily, it's the first time I heard it over the Voice of Turkey's broadcast at that time of day.


Shortwave playlist part 5

Thursday, May 19, 2016
The shortwave music expedition continues with the fifth instalment of the playlist.

1. Palyrria - Ikariotikos(Dry Mix)
Voice of Greece, May 2016

Born out of the need for experimentation PALYRRIA is a band that has devised and perfected its own, unique musical style. Created in 1999 Palyrria indulged in a mixture of western electronica and traditional music from around the Mediterranean. They call it world-electro and indeed this music is neither electronic nor ethnic. PALYRRIA has always been fascinated by traditional music and some of the bands members have worked with renowned traditional musicians, but living in Greece one realizes that traditional music goes way beyond the last millennium, back in times when people chose to express themselves in much more ecstatic and pagan ways. Ancient ceremonies around the Mediterranean have always been filled with music and musical expression. In a way, it wouldn't be too far from the truth if one was to draw a parallel between those events and the rave parties the world witnessed in the beginning of the nineties. The similarities are striking and have been the source of inspiration for the dynamic musical context of PALYRRIA. Aeolian scales, pentatonic music, instruments that come out of the depths of history, are presented alongside pumping bass lines, techno grooves, vocoders, clicks and cuts, in an attempt to create music that transcends the centuries and is both ancient and futuristic at the same time. Let the strangeness ware off and enjoy music that comes straight from the source. (Discogs)

2. Berbang - Ezim Kurdistan
Denge Kurdistane, September 2015

3. Adnane Chaouachi - Ya Ward Mfatah
RTV Tunisia, December 2013

Adnène Chaouachi (عدنان الشواشي), born in Beja, is a musician, composer and Tunisian singer. (Wikipedia)

4. Mohammed Abdu - يالله إني في رجاك
Medi 1, January 2016

Mohammed Abdu Othman Al-Aseeri, (Arabic: محمد عبده عثمان العسيري ‎) (born June 12, 1949) is well-known Saudi singer all across the Middle East. He had been described as "The Artist of Arabs". (Wikipedia)

5. Karan Khan - Inkar Kawi Na Sam Kawi Iqrar Sta Baanrha
Radio Azadi, December 2015

Karan Khan is a renowned Pashto singer, broadcaster, music developer and PhD in Pashto. (Facebook)


Endangered Shortwave Stations

Sunday, April 24, 2016
Last week, when talking to my friend and fellow shortwave archivist Thomas Witherspoon about using software-defined radios to capture and preserve parts of the shortwave spectrum, he and I suddenly stumbled upon an idea: creating a curated list of endangered shortwave radio stations. We could use such a list, we thought, to focus our own efforts and those of the community on archiving the transmissions that were the most likely to disappear in the near future.

Shortwave Radio Audio Archive endangered stations page -
Thomas went ahead and quickly put together a draft version of this list, available here, and I added a few items to it. However, it's difficult to get up-to-date information on the stations' closure plans, as the organisations that sponsor shortwave broadcasters usually don't give much notice when deciding on funding cuts, so we will have to figure out a way of keeping it current (perhaps we can also use this list as a point of contact for whistleblowers?).

The list has already helped me to prioritise my shortwave recording activities. For the past four days I have been using my indoor SDR set-up (FunCube Dongle Pro+, MacBook Pro running Windows on VMWare and SDR#, plus the entire anti-interference set-up, described in one of my earlier posts) to record a small window of the shortwave spectrum that contains two critically endangered stations: the Voice of Greece (9420 kHz) and All India Radio (9445 kHz). These are late evening transmissions that I can't capture from the park for practical reasons. Some effort was required to tune the equipment for stable indoor reception:
The effort has already paid off, however: having recorded close to 14 hours of the Voice of Greece, I noticed that the station went off the air again last night. VOG is known for its irregular broadcasting hours, so not much surprise there, yet it's hard to predict when it resumes its programming. Hopefully, fellow enthusiasts will get in on the act and record the broadcasters that are teetering on the brink of shutdown. What stations do you think are critically endangered? Please leave your thoughts in the comments section!


Denoising old shortwave recordings with SDR#

Wednesday, April 20, 2016
Readers of this blog may already know that I live in a densely built-up part of London, which is a very harsh environment for listening to shortwave radio indoors. I have come up with some RFI mitigation strategies, but these work best when the underlying radio signals are still relatively strong. That is because once a signal dips below the ambient noise floor there isn't much one can do to recover it.

At home, I enjoy listening to "blowtorch" signals like All India Radio, Voice Of Greece and Voice of Turkey (although occasionally I try my luck and listen to weaker stations). Still, sometimes the propagation is poor and even these stronger transmissions start fading into the noise. This can be especially disappointing when I start recording a particular transmission and then go off to do other things, only to find out later that the recording is heavily ridden with static. Many of my night-time recordings have ended up this way and until recently I thought that they were generally beyond "repair".

Enter SDR#. It turns out that it can process a regular audio WAV file just as if it were a real-time radio signal, meaning that its noise reduction plugins can be used to clean up the sound.

SDR# settings for denoising audio. Click the image to enlarge.
To do this, open the WAV recording either as an IQ file or using the FilePlayer front-end plugin. Chose the RAW demodulation mode and click play. You can then experiment with IF Noise Reduction parameters to find a setting that offers a good tradeoff between the noise filter strength and the amount of audio artefacts.

To give an example, here's a rather noisy recording of All India Radio I grabbed last New Year's Eve:

And here it is after noise reduction with SDR#:

Although there are a few DSP audio artefacts in the denoised version, I do like the end result and I'm sure I will be repairing quite a few more of my noisy recording this way.


Radio from the Korean peninsula

Monday, April 11, 2016
With tensions flaring up on the Korean peninsula once again, here are some Korean broadcasts I have extracted from my recent spectrum recordings:

KBS World Radio (English): April 6, 2016

KBS World Radio recorded in London, UK on April 6, 2016 at 1559 UTC, on the frequency of 9515 kHz using AirSpy, SpyVerter, SDR# software and a 2 x 6m long wire dipole antenna. The transmitter has a power rating of 250 kW and is located in Kimjae, South Korea. In the news: a possible new nuclear test planned by DPRK, as suspected by South Korean intelligence services, GPS jamming by North Korea.

Click here to download the recording // Link to the original SRAA submission

Voice of Korea: April 9, 2016

Voice of Korea, DPRK recorded in London, UK on April 9, 2016 at 1638 UTC, on the frequency of 11645 kHz using AirSpy, SpyVerter, SDR# software and a 2 x 6m long wire dipole antenna. SDR#'s IF noise reduction plugin was used to mitigate the severe levels of static arising from poor propagation conditions. The transmitter has a power rating of 200 kW and is located in Kujang, DPRK. In the news: North Korea's testing of a new intercontinental ballistic missile component, the ability to mount nuclear warheads on such missiles.

Click here to download the recording // Link to the original SRAA submission

KCBS Pyongyang: April 9, 2016

Korean Central Broadcasting Station, Pyongyang recorded in London, UK on April 9, 2016 at 1601 UTC, on the frequency of 11680 kHz using AirSpy, SpyVerter, SDR# software and a 2 x 6m long wire dipole antenna. SDR#'s IF noise reduction plugin was used to mitigate the severe levels of static arising from poor propagation conditions. The non-directional transmitter has a power rating of 50 kW and is located in Kanggye, DPRK. This is a domestic service targeted at North Korea's local population. Soothing North Korean music is being broadcast, presumably to put the listeners at ease after the incendiary war-time rhetoric.

Click here to download the recording // Link to the original SRAA submission


Very Weak Signals: Hearing Xi Wang Zhi Sheng

Thursday, April 07, 2016
AirSpy SDR and the SpyVerter upconverter
As you may have read in one of my previous posts, I enjoy using my portable SDR setup to record entire portions of the shortwave spectrum for later analysis and extraction of individual broadcasts. I am currently evaluating the AirSpy / SpyVerter SDR combination for this purpose (I shall be covering my experience with this radio in more detail in one of my next posts). One of the nice things about this SDR is that it lets me record an entire shortwave band reliably onto my tablet without maxing out the latter's processor. This evening I used it to capture one hour's worth of the 31 meter band in my local park, and once I got back home I immediately started poring over the recording in SDR# on my laptop. Late afternoons and early evenings are an exciting time to be tuning around the bands in Western Europe as many broadcasts from the Far East, South East Asia and the Pacific come in quite clearly:
I managed to pick up New Zealand quite well despite their signal being unusually weak (I confirmed this whilst out in the field by comparing my reception of it with TwenteSDR's, using my smartphone). However, the real surprise came when I ventured just below the start of the band and stumbled upon a very faint signal at 9155 kHz. Being able to rewind and fast forward through the spectrum recording is a fantastic feature of SDR#: using it I quickly found the part of the transmission where the station ID was announced. I had tuned into none other than Xi Wang Zhi Sheng ("The Sound Of Hope" in Cantonese), a clandestine station with a 100-watt non-directional transmitter located in Taiwan, according to, regularly jammed by China.

Assuming the listing is accurate, 100W is a tiny power rating by shortwave listening standards and is more suitable for ham radio operators (most international broadcasters start at 50 kW). To reach far, hams typically employ directional antennas that can concentrate the radio signal into a narrow beam. By contrast, The Sound of Hope is reported to have a non-directional transmitter, which ought to make reception even more challenging. And challenging it was, until I turned on SDR#'s noise reduction feature that made the sound pop out from the static:

I am quite pleased with this catch. I have uploaded the full recording to the Shortwave Archive and you can listen to it in the embedded player below:

The Sound of Hope: April 6, 2016

The Sound of Hope (Xi Wang Zhi Sheng) recorded in London, UK on April 6, 2016 at 1600 UTC, on the frequency of 9155 kHz using AirSpy, SpyVerter, SDR# software and a 2 x 6m long wire dipole antenna. The transmitter has a power rating of 100W and is located in Taiwan. This transmission is usually a difficult catch in Europe due to its low power rating and non-directional nature. SDR#'s IF noise reduction plugin was used to make speech more intelligible.

Click here to download the recording // Link to the original SRAA submission


Farewell to Radio Belarus

Thursday, March 31, 2016
As reported by the SWLing Post and other shortwave radio news outlets, Radio Belarus will cease broadcasting from midnight tonight (April 1, 2016). Their announcement reads as follows:
Due to the fact that National Government Broadcasting Company of Belarus Republic refused services of the Belarus Radio and TV Transmitting Center, since April, 01 transmission of radio programs of “1 National Channel of Belarus Radio” and “Radiostation Belarus” on LW, MW and SW bands will stop: 
– by transmitting center in Kolodishci:
– “1 National Channel of Belarus Radio” on 7255 KHz, 250 KW
– “Radiostation Belarus” on 11930 KHz, 250 KW
– “Radiostation Belarus” on 11730 KHz, 150 KW
– “1 National Channel of Belarus Radio” on 6080 KHz, 150 KW
– by Osipovich transmitting center in Sosnovy:
– “1 National Channel of Belarus Radio” on 279 KHz, 500 KW
– “Radiostation Belarus” on 1170 KHz, 800 KW

I can't say that I had been a regular listener of Radio Belarus in the past but I was sad to see yet another national station leave shortwave. I headed to my local park and tuned into 11730 kHz using my Tecsun PL-680 (actually slightly off frequency, to 11726 kHz, so as to cope with co-channel interference; synchronous single sideband wasn't an option — using it exacerbated the station's trademark hum for some unknown reason). Below are my recordings:

Radio Belarus (Belorussian)

Radio Belarus in Belorussian recorded outdoors in London, UK on March 31, 2016 at 1256 UTC, on the frequency of 11730 kHz using a Tecsun PL-680 radio and the supplied external antenna. The transmitter has a power rating of 150 kW and is located in Minsk, Belarus. The characteristic hum and low modulation typical of Radio Belarus are present in this recording. At 1330 UTC, BBC Bangla started broadcasting on the same frequency.

Click here to download the recording // Link to the original SRAA submission

Radio Belarus (Russian)

Radio Belarus in Russian recorded outdoors in London, UK on March 31, 2016 at 1439 UTC, on the frequency of 11730 kHz using a Tecsun PL-680 radio and the supplied external antenna. The transmitter has a power rating of 150 kW and is located in Minsk, Belarus. The characteristic hum and low modulation typical of Radio Belarus are present in this recording.

Click here to download the recording // Link to the original SRAA submission

I wanted to record the station's final English language broadcast at 2200 UTC but my tests from yesterday indicate that by the time it is aired there will no longer be a good enough propagation path to hear it here in London. I hope someone else can record it!