5 April 2017

BSS4 - Being a modern day, ham radio Phileas Fogg

Last edited: 06.04.2017

Last week was a very interesting week for me WSPR-wise. I've been tracking and monitoring the high altitude balloon BSS4. The BSS4 was launched by Mikael Dagman SA6BSS from southern Sweden on March 26, 2017. It was transmitting WSPR beacons with callsign SA6BSS on 14 and 18 MHz, as well as JT9 telemetry on 14 MHz.

The BSS4 payload on an electronic scale. Note the light weight! The payload is powered by a battery that's charged by solar panels. The battery after sundown is quickly depleted, and therefore the 20mW transmitter is working only when the balloon is in daylight.
When it had just been launched, and on the early part of its track, the balloon was too close to the Netherlands to pick up any signals from it on the 20m band. But on March 28th, while the BSS4 was floating in grid locator KN15 over Romania, it had a favourable 20m skip distance, and the first SA6BSS spots appeared in the decodes of my WSPR program!
I've only just recently (when I finished the U3S kit some time ago, see my earlier post) seriously got into WSPR, and for me this was the first reception of a WSPR high altitude balloon. The BSS4 WSPR transmitter was putting out only 20 mW, and I was wondering if my sloper end-fed half-wave wire antenna would be up to the job. It was; with the balloon floating above the far reaches of Europe, I managed to get plenty of decodes! On March 29th and 30th, during my monitoring sessions, the balloon respectively was in grid JN53 over Italy and grid JM38 over the Mediterranean Sea southwest of Sardinia, and again I was able to receive the WSPR beacons. On March 30th, I also monitored for the JT9 telemetry signals, and with succes (see below).
As soon as it had left Europe however, the next day, floating over North Africa, and on the remainder of its track over the Middle East and Central Asia, propagation and/or my end-fed wire were not up to the job anymore; no more spots were received here at my QTH. Interestingly though, PI4THT, the amateur radio club at the University of Twente in the Netherlands, was one of the stations that has been receiving the balloon all the way up to grid locator MN60 over Kyrgyzstan where the balloon's last signals were heard from. Not much later the balloon met its end, probably somewhere in the mountains of Kyrgyzstan where some of the mountain peaks are reaching over 7 km in height. I presume PI4THT have a beam antenna to their disposal, but still I find it quite amazing that it's possible to hear a 20 mW transmitter at over 5000 km distance!

Screenshot of my WSPR program. My first spot of SA6BSS on March 28th.
Spots for the BSS4 on WSPRnet, including mine. Note that BSS4 has also been picked up at PI9ESA, the radio club of the European Space Research and Technology Center of the European Space Agency in Noordwijk, the Netherlands.
The BSS4 over the Mediterranean Sea being heard by PA7MDJ on March 30th as shown on the map of WSPRnet.
Screenshot of my WSJT-X program with the decodes of the received JT9 telemetry. Beside a six character grid locator (providing a more accurate position recording than the 4 character one in the WSPR spots) the JT9 telemetry also contains information on the height of the balloon in metres. Here the BSS4 was floating at a height ranging from 8931 to 8977.5 metres. The JT9 telemetry was transmitted 330 Hz up from the 20m WSPR centre frequency and can be seen in the wide graph screen at the bottom of the screen shot (the WSPR centre frequency is at 1500 Hz). The shown JT9 frequency of 14.078000 is not correct of course. My Yaesu FT-991 was tuned to the 20m WSPR dial frequency of 14.095600 MHz, making it possible to simultaneously monitor for BSS4 WSPR beacons (with the WSPR program) and JT9 telemetry (with he WSJT-X program).
BSS4 trajectory prediction as regularly provided by Mikael Dagman on the QRP Labs e-mail group.
The last spots for BSS4 on April 2, 2017 done by PI4THT and a station in Kuwait. And it looks like Mikael Dagman has been testing another WSPR payload on April 5, hopefully for a planned BSS5 launch soon?
It was really exciting to monitor the BSS4 high altitude balloon. As written in an earlier blog entry, WSPR high altitude balloons (HABs) are launched regularly, also from other parts of the world. Some of them even manage to circumnavigate the globe! I certainly love them, as WSPR HABs provide monitoring stations like me, and probably even more so to their launchers, a modern day, ham radio version of a Jules Verne adventure novel.

Satellite view of grid locator MN60
Addendum 06.04.2017
Mikael Dagman informed me that the last reported telemetry of BSS4 was received from grid locator MN60mo. The balloon used was a silver 36 inch qualatex balloon filled with helium. The transmitter was a small version of the U3S kit running with the 3.09 firmware version, and with a TCXO added for stability. Below is another photo sent to me by Mikael showing the BSS4 payload.
Mikael also informs me that BSS5 will be launched in a couple of weeks.

 


BSS4 thread on the QRP Labs e-mail group:
https://groups.io/g/QRPLabs/topic/4656379#13577

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