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.
As many of my readers and followers will already know, these days I mostly enjoy listening to shortwave radio via the outdoor spectrum captures I make in my local park. Although I have built a system that helps me deal with urban radio interference at home, some of the weaker signals still can't make it through the indoor noise. Since I have a limited amount of time for making outdoor trips, capturing entire portions of the spectrum allows me to record a lot of shortwave signals simultaneously, which I can then explore individually at a later time. However, these trips still need to be carefully planned because the time of the day and the time of the year both affect long-distance signal propagation, and do so differently depending on the frequency range. For example, signals on the 16 meter band are usually at their strongest during the daylight hours, whereas the 31 meter band is at its busiest around sunrise and sunset. Because my current portable recording set-up allows me to capture only 10% (3 MHz) of the shortwave spectrum at any one time, I decided to carry out a systematic exploration of activity on the shortwave bands to help me time my outings so as to capture as many signals as possible during each trip.
Luckily, I didn't need to make any of my own measurements for this. For over a year, the wide-band WebSDR at the University of Twente has allowed its users to see what the shortwave spectrum has looked like over the past 24 hours in a single image. More recently, however, the creator of the service, Pieter-Tjerk de Boer PA3FWM, has opened up his spectrum image archives, so it is now possible to see the past conditions of the bands on any single day in the last two years. Intrigued by how band activity changes depending on the time of the year, I created a timelapse animation of these images by taking two from each calendar week and lining them up in sequence. With Pieter-Tjerk's kind permission, I share this animation below.
First, a really fast version to illustrate the broad effects the time of the year has on peak activity times across the bands:
The X axis represents the frequency and the Y axis is the time of day, starting at the top. Conventional wisdom about band behaviour can be easily confirmed by watching this video: the 60m, 49m and 41m bands are mostly active after dark, with the 60m and the 49m bands being generally busier during the winter months. The 31m band is most active around sunset, but carries on all night until a few hours after sunrise. The 25m band is active during sunrise and for a few hours afterwards, and around sunset during the winter months, but carries on all night during the summer. Peak activity on the 22m and 19m bands is also clustered bi-modally around the morning and the evening hours, though somewhat closer to the middle of the day than on the 31m and the 25m bands. The 16m band is mostly active during the daylight hours and the 13m band is quiet throughout the year except for the occasional ham contest.
It almost seems as though someone positioned in the middle of the image's right edge (corresponding to noon UTC) is shining two flashlight beams on the bands in a V-shaped pattern, and is changing the angle of this pattern depending on the time of the year: wider in the summer and narrower in winter. Here's a slower version of the animation that shows some finer week-on-week changes:
Thanks to this data being made freely available, visualising and understanding these dynamics will help me schedule my spectrum capture outings in the weeks and months ahead.
It's official: Radio Australia are no longer on shortwave and only time will tell of all the implications of what I feel is an incredibly short-sighted decision.
However, I hadn't seen the most recent updates informing listeners that transmissions would be cut at noon Australian Eastern Standard Time (0100 UTC). I thus missed their sign-off on the KiwiSDR, but I was able to record their last news bulletin from it, which gave me some faint hope that we might see them back on the air one day:
I made my last personal recording of their shortwave signal out in the park on January 30th, using my portable spectrum capture set-up. The signal was a lot weaker than normal at this time of the day but still perfectly intelligible.
Below are some of my favourite pieces of music that I managed to extract out of the shortwave static earlier this month, using my portable spectrum capture set-up:
Two in one! Catchy Dubstep and R&B tunes recorded from Medi1.
A melodic tune captured from China Radio International Cantonese broadcast.
An Indian song recorded from Radio Afghanistan, Kabul.
Another song from All India Radio's Baluchi service.
With 10 days to go until Radio Australia shuts down its shortwave transmissions after close to 80 years of uninterrupted service, below is a short survey of significant reactions to this development and related media coverage:
Killing shortwave disregards—disenfranchises—an unknown number of listeners. As broadcasting policy, it’s highly questionable. As strategy, it’s dumb—another bout of recurring Oz amnesia about its South Pacific role, responsibilities and history.
ASPI asked the ABC: How many shortwave listeners does Radio Australia have in PNG and the South Pacific?
ABC spokesman: ‘While there are no firm figures on audiences numbers in these regions, they are understood to be low.’
Q: What percentage of RA’s users in PNG and the South Pacific get the content by shortwave?
ABC: ‘This level of data is not available.’
No evidence-based policy there. In its closure announcement, the ABC expressed future confidence based on no knowledge of present usage:
‘Due to the nature of the technology and the remote locations of shortwave users, it is very difficult to ascertain with any precision the number of listeners who use the service… There is no available data on audience numbers for the regions affected by the closure of ABC International services. The ABC believes that technological advancement has improved accessibility of FM and online services and will negate the impact of no longer offering shortwave services.’
To stress the strangeness: Australia has no idea of the numbers or listeners in the Pacific who’ll be affected when the shortwave transmitters go silent. It has been a vital service for 75 years; with two months notice it’s redundant.
In a related and somewhat ironic development, the ABC advised Northern Territory residents to obtain satellite phones for emergency use in an informational advert about the closure of its shortwave services.
Is the irony of this really lost on the ABC management? Replace shortwave radio (~$20) with a satellite phone (~$700 plus subscription). Source: Lisa Herbert on Twitter
For AM, FM and DAB services to be viable alternatives to the ABC's shortwave transmissions, the local power grids and wired infrastructure would need to remain intact
during emergencies. The story about phone lines going down in a remote north Queensland community after storms demonstrates that this assumption is questionable at best.
Reading all of the above while the ABC management shows no signs of paying attention to the concerns of their listeners in Australia and beyond feels like watching a train derail in slow motion, with the consequences already known well in advance.
In addition to moving Radio Australia to the "Critically Endangered" part of our endangered stations list for obvious reasons, I reached out to Glenn Hauser of World of Radio to see what shortwave stations he currently considers to be under the threat of closure. He kindly provided the following response:
Endangered:
Need to add Radio Tirana, Albania. Sole transmitter has severe problems, and is reported off the air lately. The webcast has been sporadic.
Recently closed down:
It should be pointed out that R. Belarus does have some relays via Germany, probably not by its own initiative.
Radio Kuwait --- recent reports that they are getting transmitters refurbished, so maybe will be back.
Vulnerable:
Amazonia is back with two transmitters functioning well for some time now.
[New Zealand], they turned one transmitter off permanently, but the remaining one is on full schedule, partly DRM.
Perhaps you should mention that some stations survive, only thanks to WRMI putting them on SW: such as R. Slovakia International, Radio Prague, Radio Ukraine International. I am sure WRMI would be open to doing more of that.
It would be sad to see Radio Tirana go, but not entirely surprising, since they have had multiple outages and transmission problems over the past three years. At the same time, it would be great to see Radio Kuwait back on air, and it's also good news that we can take Radio Nacional da Amazonia off the "vulnerable" broadcaster list.
In this post I upload more music from my shortwave recording archives. Clips no. 2 and 3 are a bit noisy but I'm posting them as they are, since Shazam can't recognise them (otherwise I would have included them in my shortwave playlist series).
A song taken from an outdoor recording of Denge Kurstistane, which, to my ear, sounds like it could be a fusion of Kurdish and Irish musical traditions.
Below is another song that reminded me of Irish music, taken from an outdoor recording of Radio Oromiya (Ethiopia).
A slow, mellow tune from the Voice of Nigeria, recorded outdoors.
Orchestral music by Pannalal Ghosh from All India Radio, recorded indoors.
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.
Dealing with urban radio interference on shortwave
Portable shortwave spectrum capture for the urban city dweller
Recording the spectrum with portable SDR
Simulating shortwave audio artefacts
Endangered Shortwave Stations
New Year, new endeavours: ultra-portable shortwave spectrum captures in 2018
Ultra-portable shortwave spectrum capture with Belka-DX and Zoom H1
Portable SDR update
BBC World Service reporting on the death of Queen Elizabeth II
Another momentous day on captured on shortwave
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