The second Tree in Germany

#8 Uccle – Elkhausen
Vaisala RS41-SGP + Ozone / N4420564 / 17.12.2018 1200Z
πŸ”— radiosondy.info individual transport

This morning it was foreseeable that Uccle could be something this morning, if not for me, then for Kevin DO1KMT in Troisdorf. But the sonde accelerated and rushed with 380 km/h towards my QTH. Unfortunately a little south. The burst just before the airport Cologne-Bonn fit, but the parachute worked quite well during the descent and the probe was far behind Morsbach near a village called Birken-Honigessen.

Somewhat far for us, especially because I had to give a tutorial at 16:30 (but with another tutor, so there were still possibilities here) and the Bremen prediction was still in the forest. After a short linear interpolation it looked more like a field landing and my cotutor didn’t mind to do without me and so Kai and me set off.

Google Maps led us to the landing place from the south (mountains and so on) so that I already had reception 6 km away from our destination, about 3.5 km air distance from the sonde, with a 433 MHz magnetic foot antenna inside the car. Nothing that can be decoded with the RS41 Tracker (I have to put my current toolchain with Zilog on the Macbook), but quite strong. That didn’t give me much hope. The reception disappeared, and with it came my hope back: maybe it was a line of sight to the landing place on a mountain facing the road?

Until 400 m to the prediction there was not enough signal to decode, so that only then I had the certainty that the sonde was in the forest. (As it turned out in the aftermath, not 5 m from the prediction) But at least in a not so dense leafy forest, somewhere between undergrowth and real forest. So the car was parked on the nearby farm where we were greeted by three pony-sized dogs and explained our presence. From there over the fields into the bush; the parachute hung in approx. 7-8 meters height at a branch, the probe approx. 3 m under it. Shaking the tree caused the probe to sink by at least a few decimetres.

Since the branches on which the parachute was hanging and kept the probe from sinking were relatively thin, the plan was forged to push the probe down with one of the thick and long branches lying around. Unfortunately, most of them were already so rotten that they broke when they were lifted. In some distance I was lucky and found a long branch, which had to be bent over in a more recent storm, held only with a piece of bark on the stem and was about 6 m long. We carried it with combined forces to the sonde and at the upper site of the branch was arranged in such a way that a Y-fork was formed, which could be put around the cord on which the sonde hung, in order to then pull it down. The plan worked and when the probe was down even the parachute could be pulled down undamaged by pulling the cord. The Totex parachutes are massive; the big red ones made of plastic by BW and KNMI would certainly have been broken. The only loss is the temperature sensor, which is more the rule than the exception for tree-landers, especially if you have to use force.

Back at the TH, were I still was present in the las ten minutes of my tutorial (yikes) everything was examined: The sonde was in the air before, the ozone sensor comes from Droplet Measurement Technologies and has the serial number Z22756. At the top two dates are crossed out: 15.10.2018 and 13.05.15.

The probe looks as if it has been outside longer. The ring at the top is rusty and it has an interesting smell of its own. The water battery was present this time, not as with De Bilt where I was disappointed when unpacking, and this time also a heating battery is present. It’s a 9V lithium block brand Conrad Energy – didn’t even know that Conrad is also common in Belgium.

The sonde itself is a RS41-SGP, and (not to my surprise, DO1KMT had snatched one from the same batch in Wuppertal a few weeks ago, so we got to know each other) an N-serial number sonde in an EPS case. Since Uccle uses the plastic holder for dowelling and not only glues the sonde on like De Bilt, and the holder has the date code 5/14 at the back, we can now also say that the EPS probes don’t need any other holder.

The OIF board has the serial number M3330067.

Interesting to see the small differences between Uccle and De Bilt, and two ozone probes in 10 days are of course also great. Unfortunately both recycling probes. I think if I catch new probes, I’ll replace the styrofoam and send the old one back…

EDIT: As it turns out, Happysat already catched the sonde in 2015 when it landed in a forest near the Dutch/German border and sat on a tree for a few month. He returned it in september of 2018 and probably after another flight in October, which ended in a residential area in belgium, this was the third use of the sonde. Photos from Happysat are attached.

Police protected Sonde Hunt

#7 De Bilt – Herscheid
Vaisala RS41-SGP + Ozone / N4540309 / 06.12.2018 1200Z
πŸ”— radiosondy.info individual transport

Inspired even more by the failure in Wuppertal, I finally wanted to catch an ozone sonde. On 06.12. I observed N4540309 from De Bilt, which should go too south for me and land behind Siegen. However, the balloon already burst over Hagen and the probe was falling from the sky like a stone. I spoke with Kai briefly, and we decided to retrieve the probe, which had landed southeast of LΓΌdenscheid in a residential area in the meantime. I had reception at the entrance of the village, and the sonde was lying in a front garden, directly at the church. We parked at the village pub and set off by foot. The village was located on a slope, and so we only saw the police vehicle with blue lights in front of the house shortly before reaching the sonde. We went into the front garden, and already on entering I shouted: “This is just a harmless weather balloon”. Three officers, together with the occupants, stood around the sonde and looked at us. I purposefully went to the probe to convince them that it was harmless and to stop the humming.
Apparently, the residents had dialed 911 out of fear, and then none of the five people around had the idea of reading the accompanying letter. In defence, it may be said that the probe was crashed in the garden at over ten metres per second.

After that the obligatory questions (“Did you start it?”, “How do you know about it?”, “And if it falls on someones head?”) were answered, the officers left, and the inhabitants didn’t want anything more to do with the sonde and left it to us.

Instead of a water activated battery, De Bilt uses two 9V lithium blocks in series, soldered to the old wires of a water activated battery. The reamining cavity in the battery compartment is filled with polyurethane foam. The starting configuration is probe – 10 m cord – parachute – 5 m cord – parachute – 5 m cord – balloon, which was a single pile in our case. They use thick cotton cord and the same big red parachutes as the Bundeswehr.

A video shows another launch from De Bilt, but still with RS92.

Mister X in Wuppertal

NO3 Uccle – Wuppertal-Vohwinkel
Vaisala RS41-SGP + Ozone / N4510093 / 30.11.2019 1200Z
πŸ”— wetterson.de too late :’s
πŸ”— radiosondy.info public transport

To hunt for such an ozone sonde already appealed to me, and on the Friday before the first advent the forecast was favourable. In the morning I helped with the preparations for the christmas market in my old school, where I am still in charge of the PA equipment, and so it was obvious to ask the boys and girls if they wanted to join me. Jason, Jan and Martin where interested and came with me. We made sure to leave on time to reach the train at 12.23 pm; the sonde should land somewhere around Cologne. While we were still paying for lunch at the McDonalds at the Deutz train station, the balloon burst and it became clear that we were heading for Wuppertal. Jan and Martin didn’t go there anymore, because their student ticket is only valid in the VRS, Wuppertal is already in the VRR. Together with Jason I jumped into the RE; we didn’t want to be too late, I didn’t know what the competition for ozone probes was like in the Cologne area. Jason is a Sheldon, at least as far as railway transport in NRW is concerned; he knows the routes and departure times of the railways from memory. So we didn’t need the app to find out that we went back to Vohwinkel with the S-Bahn and then with a Wuppertal speciality, the diesel-powered Solingen trolleybus to the landing area, a residential area near the autobahn, where the sonde should lie in a garden.

Macbook out, SDR# on, no signal, 45 min. after landing. Knocking Doors it was. The residents on the western side of the garden knew nothing and from her garden nothing could be seen either. So we wen’t to the houses on the other side, not without first having looked from the nearby motorway bridge to rule out the worst. When we rang the bell there, the door was opened. We presented our request. “It was already picked up two young men half an hour ago”. Unfortunately they hadn’t left a note or anything, so they remained anonymous for the time being.

With mixed feelings we went back to Gummersbach. Who were the sonde hunters, were they responsible for other lost probes as well? I made a find report, in which I asked the finder to write me. Some days after the finder, Kevin from Troisdorf, contacted me. He had been on the road with his friend Kai and had been hunting sondes since 2017. As it turned out, he had already taken the DFM in Spich a few weeks earlier, but had not been able to report the find.

Baumholder is Bombing me!

In the days around 06.11.2018 numerous manoeuvre sondes started from the military training area Baumholder and as a result of the extraordinary wind some of them landed in the Cologne and Siegen area. Unfortunately I was only able to break loose on 09.11. and started a cold sonde search to get a hold of the DFMs, which are quite rare in our region. Three sondes were on the agenda: First I went to the 1600Z sonde, which was supposed to lie on a field at Spich, then to the 2030Z sonde to a riding school near Leverkusen and finally to the 1030Z sonde in a residential area near Honrath.

NO2 Baumholder – Spich
Graw DFM-09 / 17008986 / 06.11.2018 1600Z
πŸ”— wetterson.de too late :’s
πŸ”— radiosondy.info public transport

In Spich the sonde should have landed on a field or an adjacent caravan site. After the field had been searched unsuccessfully, the landlord also let me search on the caravan site, but without success. I already doubted that ON-1 had delivered the right position, but nevertheless I set off for the next sonde to Leverkusen.

EDIT: As it turned out, Kevin had also been faster with this sonde, which was almost a home game for him.

#5 Baumholder – Leverkusen-KΓΌppersteg
Graw DFM-09 / 17008997 / 06.11.2018 2030Z
πŸ”— radiosondy.info public transport

The way to the riding school in Leverkusen led through a forest along a wildlife park, and already passing a paddock I could see the red parachute hanging in a tree. I was incredibly relieved that the position had been right this time and went directly to the office of the riding school to introduce my aims. After I had received green light, the recovery began. The sonde had landed on a paddock and had already been put down behind the fence. The parachute hung in approx. 2.5 m height in a fruit tree, could be freed well however, so that I could salvage the entire set. An accompanying letter was not present, instead a glowstick was indeed. I hurried with the way back and just reached the suburban train back to Cologne.

#6 Baumholder – Honrath
Graw DFM-09 / 17008357 / 06.11.2018 1030Z
πŸ”— wetterson.de tinker sonde
πŸ”— radiosondy.info public transport

The last search on the way home in Honrath was exactly clocked, if I did not want to walk the four kilometers back to the station, I would have to catch the last bus about twenty minutes after my arrival. Three houses came into question. At the middle one nobody opened. A girl opened the door for me in the western neighbour’s house, but she knew nothing at all. Finally I had success at the eastern neighbour and was able to take my second DFM. However, the parachute had landed in the neighbour’s garden who had not been home. I reached the bus and made my way home.

Abseiling Beside the Road

#4 Essen – Kierspe
Vaisala RS41-SGP / P3510106 / 18.10.2018 1200Z
πŸ”— wetterson.de tinker sonde
πŸ”— radiosondy.info individual transport

The day before my holiday trip to England, Essen had another flight who looked nice. Together with flynamic we tried to observe the sonde during it’ s landing. We were there in time, only to be one road too far at the crucial moment: I had not noticed that Kierspe is 150 m higher than Gummersbach.

A little later we were at the landing site, which was supposed to be a few meters beside the main road. Parachute and balloon remainings were lying on the road and were overrun at second intervals. Fast action was asked, flynamic stopped beside the landing site at a parking bay, I jumped out and recovered parachute and balloon remainings of the road. After everything was secured, we made our way to the sonde, which turned out to be hanging in a deciduous tree at some height. Shaking it all didn’t help. At first I wanted to throw the string down the embankment of the road to get it closer to the probe, but it turned out that after a bit of shaking it was possible to abseil the sonde. Unfortunately the temperature sensor broke. Back in the car I noticed that Google Maps showed slow traffic at the spot where I had been standing on the road for a few minutes. But we were the ones who had eliminated the traffic obstacle!