This blog is dedicated to shortwave radio listening in the 21st century: the art of tuning into the signals of radio stations that are transmitting from thousands of kilometres away without the use of the Internet. It can be viewed as a fun hobby but also as a way to maintain an alternative, independent means of obtaining information in our digital age. Posts cover topics including shortwave radio equipment and accessories, station profiles, program recordings and shortwave radio history.
Showing posts with label Spectrum Recordings. Show all posts
After a long break, I am very happy to be bringing this blog back to life with a topical post on this New Year's Eve. This morning, I headed out ot my usual outdoor recording location in a nearby park with a new portable spectrum recorder I have built using a Raspberry Pi Zero 2W. I arrived just in time to record RNZ Pacific (formerly Radio New Zealand International) welcoming in the year of 2025, thirteen hours ahead of us here in London.
Spectrum capture in progress #AirSpy #PiZero #PiZero2W #Shortwave
Below are my recordings of this special broadcast, extracted from the spectrum capture I made in the park. The first recording starts at 10:48 UTC with the clocks turning to midnight in New Zealand 12 minutes later. Following a short news bulletin describing the celebrations taking place across the country, the station proceeded to rebroadcast the BBC World Service's Annual New Year Concert. The second recording starts just a few seconds shy of 12:00 UTC with another news bulletin followed by "Inside Out" with Nick Tipping, dedicated to New Zealand's jazz musician Rodger Fox, who passed away earlier this year, aged 71.
While making the above recordings, I was also monitoring this broadcast in real-time with my Belka portable shortwave receiver. I hope you enjoy these recordings and I am wishing you all a happy 2025!
I was very lucky to be able to spend one week in Barcelona at the end of June, which also happened to be my first holiday abroad since Singapore in 2019. Apart from immersing myself in Gaudi's architectural wonders and spending countless hours walking around the Gothic quarter of the city, I was also able to explore some of the surrounding hills. My longtime Twitter friend David EA3IEK suggested that I should try Sant Pere Màrtir for shortwave listening, so I made my way there on Saturday July 1st and reached the top around 16:38 local time.
Radio listening and spectrum capture QTH on 01/07/2023
The hill summit hosts a communications tower that was originally a television signal repeater, from which the first transmission was made in 1959.
The view of Barcelona is quite simply stunning from this location:
I set-up my 2x6m dipole antenna together with my AirSpy powered portable spectrum capture set-up right by the surveillance tower. The antenna was facing north-north-west.
Antenna span and orientation marked in red
It was a relaxing evening of listening to shortwave while admiring the mountainous landscape surrounding the city.
This particular listening spot also presented an interesting technical challenge. The Torre de Collserola television and radio tower, located at one of the adjacent hilltops, transmits multiple high power VHF and UHF signals. As David EA3IEK pointed out to me during my trip, whenever it is in the line of sight, many portable radios are overloaded with noise and FM breakthrough signals.
My trusty Belka-DX handheld receiver definitely suffered from this problem. In the video below, you can see me tuning across the 31 meter band, starting with the Voice of Korea on 9425 kHz. You can hear the blown out and distorted sounds of what is likely to be an FM transmission persisting across multiple frequencies, including an empty channel on 9580 kHz.
However, as you can see in the clip above, there are no such artefacts in the spectrum recording I made at the same time and in the same location using my default GPD MicroPC / AirSpy Mini / SpyVerter 2 SDR combination, despite the dipole antenna being many times larger than Belka's own whip! These AirSpy products appear to be immune to breakthrough FM signals and general overloading – a very fortunate outcome given the effort involved in hiking up to the top of this hill!
I was able to enjoy listening to Belka-DX a bit more on the 25 meter band, with the BBC World Service coming in nicely from Kranji, Singapore on 12025 kHz.
There was a nice but weathered site information panel about Sant Pere Màrtir, which covered the latter's early history and its use as an optical telegraphy relay hub.
All in all, it was an excellent day trip combining hiking and DXing – one that I'm eager to repeat. Below is a recording of Sri Lanka Broadcasting Company's broadcast that I extracted from the spectrum capture I made at this location.
The recording was made outdoors in Sant Pere Martir, Barcelona, Spain on July 1, 2023, at 1628 UTC using a GPD MicroPC, AirSpy Mini, SpyVerter 2, Wellbrook UMB130 balun and a 2x6m dipole.
Zanzibar Broadcasting Corporation (ZBC) is currently one of those stations that occasionally pop up on air despite no longer being listed any of the major shortwave broadcasting schedules. However, the station was very active in 2010s and was transmitting regularly on 11735 kHz in high fidelity, offering a mix of beautiful Tanzanian music, current affairs and religious programming, in English and Swahili. While reviewing some of my earliest spectrum captures I came across the following recording of this station:
The recording was made outdoors on July 28, 2015, at 1748 UTC using a Toshiba Encore Windows tablet, FunCube Dongle Pro+, Wellbrook UMB130 balun and a 2x6m dipole.
Concept Diagram of Maritime Communications. Image source: soumu.go.jp
The shortwave frequency range is commonly used for two-way radio communications between ships at sea, as well as between ships and nearby coastal stations across the world. Usually, these are low-power, non-directional transmissions of around 1 kW and can only be heard well locally. For example, in London it is often possible to hear sailors in the territorial waters of France, Spain, Portugal and, occasionally, Greece. I was therefore very surprised when I discovered what appeared to be maritime communications in Japanese on 8261 kHz in a spectrum recording I made on October 10, 2022:
The nature of this transmission was kindly confirmed to me by the user @shinyaradio on Twitter:
Hello. This is a communication between a coast station and a ship station. The content is numbers and ciphers and I don't understand it.https://t.co/DRWyHnsJ7O
The link in the tweet states that this frequency is indeed allocated for maritime communications in Japan and the power of these transmissions should not exceed 1.2 kW. If this transmission did in fact originate in Japan, the propagation conditions must have been truly excellent that evening!
October 24th marked another day of significant international developments covered on shortwave. Rishi Sunak became the fifth Conservative UK Prime Minister in just over six years and the Chinese Communist Party concluded its 20th National Congress two days earlier. Below is a selection of news broadcasts extracted from the spectrum capture I made outdoors, starting from around 1600 UTC. The BBC World Service coverage expectedly focused on Rishi Sunak's ascent to the prime minister's office, while the KBS World Service (South Korea) aired a long discussion on the party congress in China. The Voice of Vietnam and China Radio International brodcasts were also noteworthy in terms of how they placed emphases on these and other important events of the day. The spectrum capture was made using GPD MicroPC, AirSpy Mini, SpyVerter 2, Wellbrook UMB130 balun and a 2x6m dipole. Demodulation and additional signal audio enhancement was performed in SDR#.
The recordings below were made on September 8, 2022 at 1928 UTC on 7445 kHz, and at 1959 UTC on 12095 kHz, using GPD MicroPC, AirSpy Mini, SpyVerter 2, Wellbrook UMB130 balun and a 2x6m dipole. Demodulation and additional signal audio enhancement was performed in SDR#.
Amateur Radio Newsline™ is a free service to the amateur radio community. We produce a weekly audio news bulletin called a “QST” or “bulletin of interest to radio amateurs” that is delivered by a downloadable MP3 audio file from our website or through a podcast subscription. Operations are supported primarily by voluntary donations from individual amateurs and amateur radio clubs.
Below is a recording of their audio bulletin for August 26th, 2022, broadcast on Shortwave Gold on August 30, 2022 at 1703 UTC:
I extracted this recording from an outdoor spectrum capture I made using GPD Win, AirSpy HF+ Discovery, Wellbrook UMB130 balun and a 2x6m dipole.
For the first time, North Korea has confirmed a positive COVID-19 case within the country. The state-run Korean Central News Agency reported on May 12 that a “specimen from persons with fever” in Pyongyang had come back positive for the Omicron BA.2 variant, a particularly contagious strain of the virus. The phrasing of the announcement makes it unclear how many people are infected. KCNA called the development a “most serious emergency case of the state.”
By complete chance, I found this very announcement in the Voice of Korea's English language transmission that I managed to record during one of my regular outdoor spectrum capture outings:
I made this spectrum capture on May 12, 2022 using GPD MicroPC, AirSpy Mini, SpyVerter 2, Wellbrook UMB130 balun and a 2x6m dipole.
Below is a recording of the DPRK's Voice of Korea announcing the launch of the of the Hwasong-17 intercontinental ballistic missile:
I extracted this recording from an outdoor spectrum capture I made on March 25, 2022 using GPD MicroPC, AirSpy Mini, SpyVerter 2, Wellbrook UMB130 balun and a 2x6m dipole.
Lately, I have been able to make more frequent outdoor trips for recording parts of the shortwave radio spectrum using my portable set-up. While reviewing one such recording from August 31st, 2021, I noticed something highly unusual: a continuous music mix on one of the amateur bands, modulated as a lower single sideband audio signal. For readers who are unfamiliar with radio communication regulations, broadcasting music is strictly prohibited on all amateur bands in most jurisdictions. However, it turns out that the frequency in question – 7055 kHz – has now been used for some years by a number of hams for antagonistic on-air exchanges. It is likely that, in an act of desperation, someone had decided to put a stop to that (at least temporarily) by relentlessly broadcasting music using their single sideband transceiver.
The music itself is a mixture of trance, ambient house and drum & bass, but what makes this recording truly special are the various amateur radio artefacts that get superimposed onto it, such as morse code and other non-voice communications. To my ears, this gives the transmission the atmospheric feel that is so emblematic of shortwave radio in general, although perhaps in a somewhat exaggerated form. Below is the full recording for your listening pleasure:
Without any further introduction, below are three shortwave pirate radio transmissions, extracted from an outdoor spectrum capture I made yesterday with a GPD Win handheld laptop, AirSpy HF+ Discovery and a 2x6m dipole antenna. The music is mostly rock and oldies, which are the staple genres of European shortwave pirates. I hope you enjoy these recordings!
This post comes on the heels of the takeover of Kabul by the Taliban. When it became clear on Sunday that the U.S.-backed Afghan government would be unable to sustain itself against the Taliban's rapid advance into the capital city, I grabbed my portable SDR-based spectrum capture combo and headed to a nearby park. The set-up comprised of my newly purchased GPD MicroPC, AirSpy Mini, SpyVerter 2 and the 2x6m dipole antenna, which I managed to spread out across some tree branches. Using this set-up I was able to make a 3-hour long, 6 MHz wide recording between 1600 and 1900 UTC. This included the 39, 31 and 25 metre bands in their entirety. Below is a preview of what the tail end of that recording looked like when played back in SDR#:
When I returned home, I quickly scanned the spectrum capture to identify the most relevant individual shortwave transmissions. These turned out to be the BBC World Service in English and Pashto, out of Singapore, the Voice of America Deewa Radio, also in Pashto and out of Udon Thani, Thailand, and a new and seemingly unidentified transmission in Dari on 7600 kHz, continuously mentioning the Taliban. I chose 1800 UTC as the starting time for extracting individual station recordings, as by then the presidential palace had already been captured.
The BBC World Service in English has an eerie ending, as the Voice of America in Korean goes live on the same frequency before the BBC's broadcast is finished. Almost two days later, the mystery transmission on 7600 kHz was identified by Alokesh Gupta as the audio feed of Afghanistan International Television, run out of the UK by Volant Media:
The next day, I returned to the same spot – this time with a GPD Win handheld laptop, AirSpy HF+ Discovery and the same 2x6m dipole antenna as I used on the previous day. I recorded the 39 metre band between 1700 and 1900 UTC, for which HF+ Discovery offered much greater sensitivity. When I returned home, I extracted the same stations as the day before, starting at the same time:
Unfortuately I do not understand Pashto or Dari, so cannot fully appreciate most of the broadcasts that I have recorded. However, I hope they turn out to be of value and historical significance to those who speak these languages.
A coronavirus outbreak that sent New Zealand’s biggest city into a snap lockdown over the weekend involved the more transmissable UK variant, health officials confirmed on Monday, the first time the strain has been detected locally.
Auckland’s nearly 2 million residents were plunged into a new three-day lockdown on Sunday after three new COVID-19 cases were detected in the city.
Genome sequencing of two the cases - all three are immediate family - revealed they were the B1.1.7 variant. The source of the cases remains unknown, authorities said, adding they were scanning international genome databases for a match.
I used my Belka-DX to grab RNZ Pacific's 10pm broadcast, which covered this story in detail, including a lengthy listener-led Q&A session with a local epidemiologist. I got my Zoom H1 recorder to capture Belka's I/Q output, which I then demodulated in SDR#.
This is a quick "how-to" post on making spectrum recordings with the latest
model of the ultra-portable Belka shortwave receiver, the Belka-DX.
A number of positive reviews of the previous model of this receiver have
already been posted online. The new version boasts greater sensitivity,
extended shortwave coverage and the ability to monitor I/Q – or radio
spectrum – data in real time.
A separate 3.5mm stereo port is used for outputting I/Q data in analogue
format. This seems an unusual design choice: nowadays, most SDRs send I/Q data
digitally over USB (e.g. see FunCube Dongle Pro+).To get SDR applications to
work with this data, Belka's I/Q output needs to be connected to the line input
of a regular PC sound card. The digital —> analogue —> digital
conversion chain will inevitably result in the addition of small amounts of
noise to the final spectrum output. However, one advantage of this design
choice is that it is possible to capture this data using a portable audio
recorder.
Belka DX I/Q output port
While Belka's I/Q sample rate is reportedly 192 kHz, few recorders are capable
of capturing audio at this rate (and none of them are cheap or particularly
compact), and the 96 kHz option is far more widely available. In practice,
recording at this rate means that roughly 48 khz on each side of the centre
frequency become truncated, but on shortwave, 96 khz can still pack several
broadcast stations (or, alternatively, a few dozen ham radio transmissions).
Additionally, DSP tools in SDR applications such as SDR# can be used to clean
up I/Q recordings in ways that are far superior to what's possible to achieve
with regular post-processing of audio recordings.
I made several field spectrum recordings with my Zoom H1, connecting Belka's
I/Q output to the recorder's line input and using the "WAV @ 96 kHz / 16 bit"
setting. I found that keeping the input level between -24dB and -12dB results
in sufficient gain for later analysis without overloading the recorder.
It's worth noting that the gain and the slight offset from the tuned centre
frequency seem to change depending on both the frequency and the chosen
demodulation mode.
Results
First up is the Voice of America recording I made on 06/11/20 in a London park.
To assess the quality of my I/Q capture method I recorded the audio output in
parallel using my Sony ICD-PX333. I set Belka's demodulation mode to "AM2", which
is its pseduo-synchronous AM detection setting. Below are the two
recordings, with the I/Q data demodulated in SDR#:
Belka's own demodulation is a little on the distorted side compared with SDR#'s I/Q demodulation. This is probably due to the specifics of its "AM2" setting.
Note that I'm using SDR#'s handy "invert spectrum" and "correct IQ" options,
and that I've modified the spectrum recording file names so that the centre
frequency is displayed correctly.
Below are two more examples of this I/Q capture method and their audio recording counterparts. For the latter, I set Belka's mode to LSB with 50 Hz lower and 4 kHz upper frequency cutoffs. I also used Youssef's excellent noise reduction plugin when demodulating I/Q.
Radio Rebelde on 12/11/20 at 07:01 UTC
Radio Rebelde was barely registering on Belka's SNR meter but the audio is perfectly intelligible, while SDR#'s noise reduction takes this intelligebility to an entirely new level.
Finally, here is a full I/Q capture of a CQ constest on 40m on 21/11/20, recorded in the same park location (click here to download the original WAV file). An
Over The Horizon Radar signal makes an unfortunate appearance during the first
20 minutes of the recording, causing severe interference. You will also notice a few hams ignoring the contest altogether and happily rag chewing!
Overall, this is by far my most portable shortwave spectrum capture combo: it
is handheld and absolutely no antenna set-up is required – just plug in the
supplied telescopic whip and you are good to go. The reduced bandwidth
compared to my AirSpy SDRs is a significant limitation, but it was only a few
years ago that I was making recordings with a FunCube Dongle Pro+ that only
provided double the above sample rate. It would be amazing if Belka's next
model included a microSD card slot and the ability to record the I/Q data
directly to it, but for now I am very happy with this way of making spectrum
recordings on the move.
Every year, the BBC World Service makes this special programme for just 40 listeners: the team of scientists and support staff isolated at British research stations in the Antarctic midwinter. The Antarctic Midwinter Broadcast is unlike anything else on the BBC World Service. Presented by Cerys Matthews, it features messages from family and friends at home as well as music requests from Antarctica. For decades it has been part of the traditional midwinter celebrations.
To listen to the 21:30 BST broadcast on 21st June on shortwave, please tune to:
5790 kHz from Woofferton UK 7360 kHz from Woofferton UK 9580 kHz from Ascension Islands
Below is my recording of the 5790 kHz transmission, broadcast out of Woofferton, UK on 21/06/2020 at 2130 UTC (not BST as stated on the BBC website). The recording was made using GPD Win, AirSpy Discovery Dual Port and a Sony AN-LP1 active loop antenna, positioned on the balcony of my indoor QTH in London. Many listeners from further afield have reported difficult reception conditions, so being close to one of the transmitters felt a bit like cheating, but it was nice to catch this transmission all the same.
Satellite view of Voice of the Islamic Republic of Iran transmitter site in Sirjan
This is a quick post with no particular theme to it, apart from the fact that I recorded two overseas English language broadcasts that are not the usual suspects for my urban indoor location (such as Radio Romania International or China Radio International). One of the countries, Iran, has made substantial improvements to its shortwave transmissions directed towards Europe:
Might be old news but compared to my recordings from last year, Iran have really fixed their transmitter and the audio is no longer severely under-modulated. Recorded yesterday with #AirSpy HF+ discovery and #YouLoop on the balcony, all times BST. pic.twitter.com/P9QanKEeRt
Below are recordings of the Voice of Turkey and Voice of the Islamic Republic of Iran, made on 19/06/2020 using an AirSpy HF+ Discovery and a YouLoop antenna, the latter positioned on the balcony of my indoor listening post in London. SDR# noise reduction and wide filter bandwidth were applied to Iran's signal, resulting in near-FM audio quality.
The programmes focus on current affairs and international relations. Curiously, both countries dedicate more time to the impacts of COVID-19 outside of their own borders.
In August 2019 I visited Singapore, where I was able to test a pre-release sample of the AirSpy HF+ Discovery SDR, kindly sent to me by Youssef. Due to a very busy schedule I was only able to make two short outdoor radio recording trips, amounting to three hours in total. Needless to say, the advantages of portable shortwave spectrum capture manifested themselves fully in these hurried circumstances. I made these two trips on August 27th and 29th and I shall start with the latter outing as that was when I made my most prized recording to date.
East Coast Park, 29/08/2019
Spectrum capture QTH on 29/08/2019
East Coast Park is Singapore's largest and occupies 15km of the island's coastline. I chose this location because it was easily accessible and not particularly crowded on the day:
My recording set-up consisted of the GPDWin 5" mini-computer running Windows 10 and SDR# 1631, AirSpy HF+ Discovery and a long wire antenna:
I arrived at 1723 local time (0923 UTC) and after experimenting with reception on different bands for about an hour I settled on the 49 meter band and started recording it just before 1100 UTC (after grabbing a coffee from the large Starbucks situated right behind me). An hour later, as the beach became dark and windy, I packed up my equipment and went back to the hotel. Later that night I reviewed the spectrum capture file and the very first station I stumbled upon was one that had eluded me since I returned to the shortwave listening hobby in 2013: Myanmar Radio.
Below is a one hour recording of this station extracted from the spectrum capture. It contains a mixture of talk, traditional songs and national rock music. The 50kW non-directional signal on 5915 kHz is listed as "Myanma Radio Naypyidaw Service in Minority Languages", although I have not been able to establish the exact language of this broadcast. Some time ago one Shortwave Radio Audio Archive contributor said that "this may be one of the most exotic countries still left on shortwave". I agree!
Radio New Zealand International (RNZ Pacific)
I have a special fondness for RNZI as it was my first bit of long-distance DX back in 2013 when I was staying in the Russian countryside. Receiving this station in Singapore would always have been a lot less challenging but it's still nice to hear this old friend from the Pacific on the airwaves, especially as it has been a harder catch in Europe in recent times. Below is a one hour recording RNZI's signal extracted from the spectrum capture file.
KCBS Pyongyang
This is the domestic arm of the North Korean radio service, which regularly makes it into Europe on 9665 and 11680 kHz (almost always faintly) but far less often on this 6400 kHz frequency. From NorthKoreaTech:
The Korean Central Broadcasting Station (KCBS) (Korean: 조선중앙방송, Chinese: 朝鲜中央放送, Japanese: 朝鮮中央放送) is the main domestic radio network in the DPRK. It sits under the Central Broadcasting Committee of the DPRK (called the Radio and Television Committee of the DPRK until 2009).
KCBS broadcasts from 5am to 3am local time via a network of medium wave and shortwave transmitters that cover the nation. The powerful transmissions can easily be heard in neighbouring countries, including South Korea where some of its frequencies are jammed.
A central program is broadcast from Pyongyang on most transmitters through the entire broadcast day, but some are reported to carry regional programming between 2pm and 3pm.
Below is a one hour recording of this signal. Note the militant style of the radio presenter and the rousing patriotic music. There were lots of other North Korean transmissions available during both of my outings but I will avoid repetition here.
Echo of Hope
South Korea's clandestine counter-broadcast on shortwave, beamed into North Korea from Hwaseong but picked up very clearly in Singapore. There isn't much information available on this broadcaster online, although apparently a few listeners managed to obtain the station's QSL cards via South Korea's international broadcaster, KBS World Radio. Below is a one hour recording of their signal.
The Australian Bureau of Meteorology broadcasts marine forecasts and warnings to mariners over shortwave from Charleville (VMC) for eastern waters and Wiluna (VMW) for western waters. The transmitter specifications for the VMW broadcast state that it is powered at 1 kW (presumably non-directionally, based on the map above) and according to the schedule the forecast recorded below was supposed to be for Western Australia (Northern Zones: NT-WA Border to North West Cape) and the Northern Territory. This signal occasionally makes it into Europe in winter but I've not yet managed to pick it up in London.
Radio Nikkei 1
Radio Tampa QSL card from the late 70s. Source: kusanagi1965
Radio Nikkei 1 (Radio Tampa until 2004) is a nationwide commercial shortwave radio station in Japan, operating from Chiba-Nagara at 50 kW since 1954, and was another first catch for me. Wikipedia's description makes it sound like a fairly unique station in today's shortwave world:
The station features the following four genres as the core of its programming: finance, JRA horse racing (weekends), health-medical, and culture.
Below is a one hour recording of the station's 6055 kHz signal extracted from the spectrum capture.
Voice of Vietnam National Channel 4
This is one of Vietnam's many domestic shortwave services, broadcasting non-directionally at 20 kW from Đắk Lắk and yet another first for me. Below is a one hour recording of this station extracted from the spectrum capture file.
BBC World Service transmitting from Kranji, Singapore
Amidst all of this DXing fun it would perhaps be easy to forget that Singapore is home to the Kranji transmitter site, which several international broadcasters use to reach listeners across South-East Asia. My QTH in East Coast Park was merely 20km away from Kranji and the video below clearly shows how strong the local 125 kW signal of the BBC World Service was on that day. The most surprising part was just how well AirSpy coped with having that monster signal next to all the weak transmissions I extracted above: at no point did it look like the ADC was anywhere near its saturation point. If I had more time I would have tried to visit Kranji and check out the transmitters; I hope to do so during one of my future trips to this country.
Pasir Ris Park, 27/08/2019
Spectrum capture QTH on 27/08/2019
Two days earlier I visited Pasir Ris Park on the other side of the island. The park is located right next to Singapore's Changi Airport. It's a great location for DXpeditions because overnight camping is allowed, albeit only with a permit obtained via the National Parks Board's website (something that I would also like to do during my next visit).
I arrived at the recording spot at around 1830 Singapore time and started capturing the 25 meter band 90 minutes later (at 1200 UTC). In retrospect this wasn't the most interesting band to record as it was mostly populated with services from China Radio International and China National Radio, which you can hear pretty much anywhere in the world. However, I did manage to extract a few interesting transmissions:
Voice of Vietnam's English language service to South East Asia and the Pacific
I have made many recordings of the Voice of Vietnam's English language broadcasts, which can be heard in Europe on 7280 and 9730 kHz at 1600, 1900 and 2130 UTC. What I didn't realise before catching this particular transmission is that the content of the international news bulletin depends on the region to which it is being broadcast. The European transmissions I pick up in London are typically focused on Vietnam-EU and Vietnam-US relations, while in the recording below, the news is Asia-Pacific-centric. To me, this shows that the Vietnamese government still take their shortwave operations seriously.
NHK World Radio Japan
NHK World is the international arm of the Japanese state broadcaster, NHK. The one-hour transmission below was beamed south-west in Japanese out of Ibaragi-Koga-Yamata, at a mighty 300 kW. Perhaps this was the next easiest signal to catch after the BBC World Service out of Kranji, but the reason I include this recording here is that by coincidence I stumbled upon the relay of ABC-Z's weekly program on NHK Radio 1. ABC-Z are a popular Japanese boy band who have been active in under various guises since 2001. You can catch their songs at 18:40, 36:26 and 50:48 in the recording below.
Members of A.B.C-Z
Republic of Yemen Radio (clandestine / Saudi Arabia)
Distance calculation by Google
Republic of Yemen Radio is a clandestine radio station broadcasting out of Saudi Arabia. It delivers programming reflecting the position of the Saudi-led coalition that participates in the ongoing Yemeni civil war. The precise location and power rating of the transmitter are not officially disclosed but are believed to be Jeddah and non-directional 50 kW, respectively. Given the 7,331 km distance to the transmitter site and the non-directional nature of the broadcast, this DX is still somewhat noteworthy.
Overall, I couldn't be happier with what I managed to capture with my portable SDR set-up in the limited time available. Although I wish I had spent more time on the lower bands, as that is where more of the local and exotic stations of the region reside, there's always the next time, and yet another reason to come back.
The Voice of Greece are well-known for their multi-hour sessions of phenomenally diverse music from around the world. So, without much further commentary, here is a recording of their signal made yesterday at 1904 UTC using AirSpy HF+ Discovery and the YouLoop passive loop antenna, mounted onto a tripod on the balcony of my QTH. The first hour contains tracks from Indonesia, the Middle East, Latin America, and beyond, while the second hour has a selection of traditional Greek music.
All India Radio office in New Delhi. Photo by Sanjeev Verma
When I returned to the shortwave bands two weeks ago I was sad to learn that All India Radio had suspended its overseas shortwave transmissions at the end of March, owing to the COVID-19 lockdown imposed by the Indian government. It was also being reported that AIR National Channel – a more difficult catch in Europe compared to the External Services Division (ESD) broadcasts – was running on reduced power. However, it seems that we can now hear AIR's English language news bulletins once again, on the same frequency where a limited number of non-English language ESD broadcasts were announced to be broadcasting two weeks earlier. The transmission takes place daily at 1500 UTC on 11560 kHz and is only 30 minutes long. The mixture of English and Hindi suggests that it is a high-power relay of AIR National Channel programming. Below is a recording of this transmission made on May 21st, 2020 with a PocketCHIP handheld Linux computer, AirSpy HF+ Discovery and a YouLoop passive loop antenna. The antenna was positioned on the balcony of my current QTH in London.
This blog was started on a hot and sunny afternoon in July 2013, while enjoying listening to some distant signals with a Roberts R9962 shortwave radio.
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