Monitoring reactions to North Korea's 6th nuclear test on shortwave

0
Monday, September 04, 2017
Graphic from the United States Geological Survey showing the location of seismic activity at the time of the test
From Wikipedia:
North Korea conducted its sixth nuclear test on 3 September 2017, according to Japanese and South Korean officials. The Japanese Ministry of Foreign Affairs also concluded that North Korea conducted a nuclear test. The United States Geological Survey reported an earthquake of 6.3-magnitude not far from North Korea's Punggye-ri nuclear test site. 
South Korean authorities said the earthquake seemed to be artificial, consistent with a nuclear test. The USGS, as well as China's earthquake administration, reported that the initial event was followed by a second, smaller, earthquake at the site, several minutes later, which was characterized as a collapse of the cavity. 
North Korea claimed that it detonated a hydrogen bomb that can be loaded onto an intercontinental ballistic missile (ICBM) with great destructive power. 
Photos of North Korean leader Kim Jong-un inspecting a device resembling a thermonuclear weapon warhead were released a few hours before the test.


Using my portable spectrum capture setup, I recorded the 22 and 19 meter bands between 13:30 and 14:30 UTC and the 31 meter band between 16:00 and 17:00 UTC on the day of the nuclear test. Below are the news bulletins I extracted from these two recordings, which demonstrate varying reactions to this event from the relevant international players:

First, the news in English from the DPRK's state broadcaster, Voice of Korea, with the formal announcement starting at 5 minutes, 6 seconds into the video:


South Korea's reaction, broadcast via KBS World Radio, was characteristically terse:


Voice of America interviewed their own White House correspondent who lamented that nothing is working to steer North Korea away from the path of nuclearisation:


Meanwhile, China Radio International considered DPRK's nuclear test as worthy of only the number 3 spot in their list of headlines. Perhaps this shouldn't be surprising: some analysts have opined that Kim Jong Un had deliberately timed the nuclear test to coincide with Xi Jinping opening the annual BRICS summit in China as a show of defiance towards the Chinese leader.


These are interesting times to be monitoring shortwave radio broadcasts, and in this case particularly so because North Korea uses the medium extensively to inform the world about its activities while investing relatively little into other methods of communication. Continue reading →

Endangered stations: April 2017

0
Friday, April 14, 2017
CBC dismantles the transmitter towers on Tantramar Marsh land in March 2014.  Image credit: CBC.ca
Some new endangered shortwave station entries for this month:

Endangered:


Radio Nacional da Amazonia was reported off the air for several weeks in March and April 2017, apparently because the Brazilian government didn't allocate the funds for the electrical power needed to run the service (information via Glenn Hauser / World of Radio).

Medi1, Morocco has been off the air in the first two weeks of April.

Recently closed down:


Albania's Radio Tirana closure has been finally confirmed after months of transmitter problems and service interruptions (information via Glenn Hauser / World of Radio). Continue reading →

Shortwave gems: March 2017

0
Monday, March 27, 2017

This month's episode of the shortwave gems series, extracted from my indoor spectrum recordings:

Carnatic instrumental music from All India Radio that at times sounds like a mixture of Trance and Drum & Bass!



A very interesting performance from Radio Thailand that is strangely reminiscent of a certain famous band form the west (which one is it?).



A pop song from the Voice of Turkey that seems to have borrowed a bar or two from "Don't You Worry Child" by The Swedish House Mafia.



Folk music from Radio Romania International.

Continue reading →

Shortwave gems: February 2017

0
Tuesday, February 28, 2017

Some great music this month, extracted from my spectrum recordings:

A fast-paced, intense musical composition recorded from the Voice of Greece.



A vocal piece in Arabic, performed in a surprising style, recorded from Radio San'aa.



A song recorded from the Laotian service of FEBC Radio (broadcasting out of the Philippines).



Dreamy Carnatic instrumental music recorded from All India Radio.

Continue reading →

Visualising shortwave band activity throughout the year

2
Sunday, February 12, 2017
24-hour shortwave spectrum image, showing activity for a single day in the first week of February 2017 (©PA3FWM, Twente WebSDR).
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. Continue reading →

Farewell to Radio Australia

5
Tuesday, January 31, 2017

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.

Having heard that they might switch off their transmitters at midnight universal time on  January 31st, I monitored their 17840 kHz signal remotely via a KiwiSDR server located in New Zealand (there is no night-time propagation path from their Shepparton transmitter site to the UK at this time of the year). I was encouraged to find that they were still on the air after midnight UTC and thought this meant they would go on until midnight Sydney time, in which case I might be able to record their sign-off from my usual outdoor shortwave listening and spectrum capture spot.

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.


Three and a half years earlier, I tuned into them for the very first time, while on a trip to Moscow, Russia:


Fairwell, Radio Australia. You will be missed. Continue reading →