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.
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!
For someone who has been into the shortwave listening hobby for many years, I have embarrassingly few QSL cards. So I was very pleased when I rediscovered what I thought was a long lost photo of an e-QSL card from Radio New Zealand International (now RNZ Pacific) from 2013. Here it is, alongside the recording that the card is confirming and the equipment I used to capture the former. Seeing this card makes me appreciate how lucky we are that RNZ Pacific are still with us on shortwave today.
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#.
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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