Radio Blog

I am happy to inform you that both launches went fine and both payloads were recovered.

After the rainy weather of the past few days the launch day was starting with a cloudy sky and mild temperatures, which made the installation of chase equipment and setup of launch area a bit easier compared to high temperatures. According to the forecast the weather was expected to get sunny with only a few scattered clouds during the mid of the day, and gladly the forecast was right!

The first balloon was launched briefly after 0800 UTC, for the rather light-weight payload a Totex800 was used. The flight roughly followed the predictions that were run earlier, however, with a burst altitude of 29203 m we were not able to reach a new club internal altitude record. Also the rather “early” burst caused the payload to go down in an area further east than the recovery teams had planned for.

Not a real issue but there are a few factors that could render such a landing into a “payload lost” over here, mainly the fact that we have a large NATO military training area which is a restricted military territory.

DL0CN-11 decided to land in a corn field. An octo-copter was used to locate the payload, a rough position already had been received through APRS and direction finding.

Using the octo-copter to find the precise location of the payload permitted the search team to move towards it directly and therefore keep potential damage to the plants (which are more than 2m high here at present) as low as possible. This approach also permitted to check for boars which often are hiding in corn fields in summer and get quite aggressive if disturbed.

The second balloon (callsign DF0XX-11) was launched at about 1000 UTC. As seen in the predictions the path in total was a bit more east than the previous flight. Therefore we were not entirely disappointed about a burst at 29440 m as any higher burst-altitude would have risked the payload to land in the middle of the military training area. This would have made recovery of the payload more difficult. The landing of the payload already was on the border of the military training area, 50m from the impact point signs clearly declared the beginning of restricted area.

Alltogether it was a great saturday, the team-work of recovery teams was a fine job and communication through amateur radio was the right choice as at most search areas the mobile phone coverage was not too good. Communication between search teams and launch area was performed through the “Heiderelais” DB0RH. This also permitted other HAMs to request information about the project and follow the search efforts. Thanks to all HAMs that kept the relay free for the day and might have used direct communication for their conversations.

In the tradition of the High Altitude Amateur Radio on Bord Balloon Projects of 2010 and 2012 the Amateur Radio operators of the DARC Ortsverband H05 (local subsection in District H of German Amateur Radio Club) will be performing 2 Balloon launches on Saturday, July 26 2014.

The payloads which will be attached to Helium filled Latex Balloons (Type: Totex1000) will transmit live telemetry data via APRS (Automatic-Position-Reporting-System) and a voice beacon. The telemetry data will include the external and internal temperature, air pressure, altitude and battery voltage.

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Mission logo for the HAAROB Project

As promised I will tell you about the HAAROB CBM2012 project, which I have been following through media recently.

This morning another article appeared in newspapers, telling about a test flight being scheduled for tomorrow, 23 June 2012 at 10.00 AM local time.

This launch was added to Amateur Radio High Altitude Ballooning Mission Announcements Website (see here).

The launch tomorrow can be considered to be the final test of the communication interfaces on board of the balloons that are planned to be launched on 07.07.2012. The test will show if the APRS equipment, which was developed by the local HAMs is working in the expected parameters. With about the size of a pack of smokes and the overall weight of 150 grams the equipment used tomorrow will be rather light-weight compared to the size of the 2 balloons that will start in July.

According to Meinhard F Guenther (DL2MF) the final weight of the balloons will be 700-800 grams.

2 scientific payloads will be sent to close-orbit high altitude, and both experiments aim to investigate the effects of high-altitude radiation on organisms. The first balloon which is scheduled for launch at 10.00 AM MESZ on 07.07.2012 will carry a project developed by Pia, a student of the Christian-Gymnasium-Hermannsburg, who is active in the “jugend-forscht AG” (a voluntary group of students participating in science activities with the purpose of entering the German “jugend forscht” Contest that awards outstanding projects of young scientists). The project of Pia will expose moss samples to high altitude radiation. Once the balloon and “payload” has been retrieved Pia will investigate the samples on effects caused by the radiation exposure.

The second balloon will carry the project developed by Heidelberg University. A mini-lab with cell-samples will be exposed to the high altitude radiation.

Whereas the 1st launch will provide position reports through APRS (144.8 MHz) and a synthesized voice system on 144,2 MHz, the second launch will only provide an APRS data stream on 144,8 MHz.

To make sure that the balloons are found in the terrain of their landing site, a total of up to 5 mobile teams will chase the balloons and return them to the launch site.

Summary of information:

Greetings,
this blog has been dormant for quite a while, mainly caused by involvement in work and studies which limit my abilities to engage in freetime activities.

So before I start telling you about HAAROB CBM2012 I would love to give you a short update on my situation relating to amateur radio and shortwave listening.

I successfully became a HAM during my studies in Southampton, UK, and was licensed under the callsign 2E0SGP, however, intermediate licence callsigns cannot be accepted by the German authorities, therefore I had to find some way to become a proper HAM in Germany.

One way would have been to go for a German exam in order to become licensed, however, due to the fact of having been in the matter of HAM stuff using mostly English as language for studies and communication, I decided to go for the US Exam instead.

First plans were to attend the Hamvention in Friedrichshafen, the largest German HAM trades fair and exhibition. However, due to the long trip from here to southern Germany and the expenses involved it would not have made much a difference to sitting a German exam. Gladly the great folks of “Peine PileUp People” (another German HAM-Club) offered an exam at only 70km drive from here… you can imagine how willingly I decided to attend that exam.

On a Saturday morning I took my mom’s car (thanks mom!) to get there.  The US system permits you to sit all 3 exams (Technician Class, General Class and Extra Class) on one day, as long as you do not fail one of the exams you only need to pay USD 15 for the exam. I took the technician class easily but messed up a bit on General Class, so I repaid 15 bucks to resit the General Class, passed and then took the Extra without big issues at all… that is the story behind the callsign AK4LT being issued to me.

Once I had the US callsign I was able to apply for a German callsign, and a few weeks and calls with authorities later I was glad to go on air with the callsign DL1SGP, as you can see it references to my first callsign from the UK.

Since then I have been able to invest some money into my shack, run more than hundred QSOs (mostly in digimode but lately am getting fun from SSB as well). Today I decided to join the local group of the German HAM Club DARC, so as you can see things still are progressing.

Vy 73,
Felix – DL1SGP

Greetings,
Back in Germany I often used to decode the signal of radiosondes which were used for analysis of the atmosphere, so thinking back at that I came to the idea to give it a try. Even though my equipment here in halls is usually about fine for the job of decoding the sonde signal, the location is giving a few restrictions being that I am RF technically shielded by the buildings around me and can only use the antenna indoors as I cannot entirely open the window due to security matters, I guess they are afraid I would fall out of window, which is not healthy from 7th floor.
But well, on Friday (18.02.2011) I was awake at about 6.30am and my SDR was showing a quite stable signal from the radiosonde. I was able to adjust the gain parameters in order to give me some nice performance.

Decoding a radiosonde always follows the same procedure, first of all you need to get the newest almanac for the GPS data from the US Coast Guard (or other sources) once you have told the software to use the almanac, it technically would be able to show GPS positions for the sonde, but before that can happen, the calibration has to be found.

Once that calibration has been reached, the software for the decoding shows quite useful data such as:

• Pressure
• Pressure altitude
• Temperature
• Dew point
• Rel humidity
• Rate of climb

The GPS Section shows data such as:

• GPS latitude
• GPS longitude
• GPS altitude
• GPS residual
• GPS wind

All data is nicely represented in a few charts, but I will come to that later by providing a few screenshots.

Let’s talk about the location that the sonde is launched at. All information required to start your own decoding can be found on the website http://www.radiosonde.eu/ which unfortunately is not available in English right now, so I feel free to provide a direct link to the list of UK launch stations, this might make it easier for you to find the data you are interested in:
UK Launch Stations

So the station I was particularly interested in was the Larkhill station, the map with the locations of where the radiosonde landed indicated them to be passing over Southampton, which raises the chance of them to be picked up by my equipment. As I have received the radiosonde once before, it’s details were added to the Global Frequency Database the details for the radiosonde entry are to be found here.

The hardware (type of radiosonde) being used at the Larkhill station is the Vaisala © RS92SGP you can find the datasheet on the company website.

This is what the RS92SGP radiosonde looks like:

Source: Vaisala ©

In order to decode the signal, I used the FuncubeDongle SDR (FCD Website) which has not only proven to be a valuable asset in decoding satellite data but also provides great functionality for other use cases. The following picture shows you the signal of the radiosonde at 404.400Mhz, the upper display is the waterfall display, below the spectrum can be found.

Graphic representation of the radiosonde RF signal

For an audio example on what the radiosonde signal sounds like, please click here.

The decoding is done by the SondeMonitor Software from COAA (COAA Software), this software is available as trial version, which permits you to try if the signal that is picked up by your receiver can be decoded or not. The decoding is done via the soundcard input of your computer.

If your computer decodes the signal, you are likely to get data as shown on the screenshots below.

Data received from the radiosonde

chart representation of received data

If you should be tempted to try this out yourself by now, I hope that you will be successful in decoding the radiosonde signal. In case of problems you can feel free to ask me for help, either by email or directly on one of the occasions that we meet.

Greetings everyone,
so you made it to my radio blog which was set up on 16 February 2011, great! This blog will be used to give you an insight to my various activities in relation to radio communications.

I will try to keep things as simple as possible to allow everyone to participate, at the same time I might take a critical look at some aspects as where it comes to the security of our privacy. Being a German I might be a bit too sensitive about privacy and data protection, anyhow it never hurts to raise awareness how much of your data is disclosed in regular life situations.

Throughout the time I will also add 2 or 3 further pages which will give you some presentations of what I am talking about, it likely will happen that I add mini presentations on some subjects as well, so keep checking if something new is on here!

Please understand that my duties do not permit me to be a “full time” blogger, this means that sometimes it may take a while between updates.

Enjoy your stay!
Felix