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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 Lüdenscheid 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.

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.

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.

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.

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.

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.

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!

The Essen midday sonde of Saturday, 29.09.2018, P3020155, landed in a residential area in the eastern outskirts of Leverkusen. On Friday morning after, I was in Cologne for a lecture that was cancelled at short notice and decided to look for the sonde. Arrived there by bus and train, the first way led into the forest behind the property, in which I suspected the sonde. I could not see anything in the trees, and a very high and steep slope separated me from the property. So I started the way back and due to the geography I had to take a considerable detour, so some 20 minutes later I stood on the other side in front of the three terraced houses in question.

Already at the first I had success; an older lady opend me, and when I explained my concern, she asked me to the garage. The sonde was already awaiting me there. But first I was the one of interest. Whether I was a friend of the neighbor’s son to whom she wanted to give the sonde for the physics class. Why then a (designated) amateur radio operator from Gummersbach would know that a sonde had landed at her backyard. How exactly that worked. Unfortunately, the parachute hung out of reach in the first tree of the forest, the sonde was lying on her lawn and had been salvaged immediately. Very happy about the first successful cold sonde hunt I started my way back a little later.