Such a nice lady

#3 Essen – Leverkusen-Steinbüchel
Vaisala RS41-SGP / P3020155 / 29.09.2018 1200Z
🔗 wetterson.de tinker sonde
🔗 radiosondy.info public transport

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.

Preparation: F

#2 Essen – Wildbergerhütte
Vaisala RS41-SGP / P2531249 / 04.10.2018 1200Z
🔗 wetterson.de in storage
🔗 radiosondy.info individual transport

I was sitting in the lab at the TH when the midday sonde P2531249 from Essen, which was supposed to land behind Siegen, did not burst high and hit Wildbergerhütte with hardly any brakes. Kai, who sat next to me, suggested to go there, and after a side trip to mine, where I quickly grabbed Macbook, SDR and Yagi, we set off. Arrived there, the disappointment followed. My Macbook had only little battery left and the prediction was very vague. I had no reception at the prediction. Kai had taken his laptop, a real hefty thing, and I had sent him my toolchain. Nothing had been installed yet. So that was done in the car.

Unfortunately SDR# was so stuttery that a decoding was not possible when we could pick up the signal a few hundred meters further. In addition, the frequency axis was somehow not right so the reception was a gamble. After half an hour searching on the meadow from where the signal came, without any real results, it became dark.

We decided to go back to the village where we could pick up the signal for the first time to make one last attempt. And indeed: a faint RS41. Don’t lose the bearing now. I held the Yagi, Kai the laptop: This is how we walked up the mountain in front of us, down the mountain again, through a forest, a steep embankment, across the road. At the end we stand at a field, it is pitch dark, and Kai is the first to see the green LED of the barometer board flashing. A meadow landing, barely audible with the big yagi from 700 m with a mountain in between. As it turned out later, the landing site was a stone’s throw away from the radiosondy prediction we hadn’t paid attention to, but some hundred meters away from the one made by wetterson.de.

Nobody knew Anything

NO1 De Bilt – Solingen
Vaisala RS41-SGP / P0950597 / 24.09.2018 0000Z
🔗 wetterson.de lost despite thorough search
🔗 radiosondy.info public transport

At the end of September I went to a GIS workshop in Cologne for a few days, and as it so happens, P0950597 from De Bilt landed with very good prediction in a suburb of Solingen, the trolleybus stop right across the street. This was worth a try, especially as I always wanted to use the trolleybus in Solingen, so I made my way to Solingen after the workshop. The sonde must have landed either in the gardens, the backyards or on the apartment buildings standing there.

When I arrived there, I first looked on the street, then on the parking lots behind the houses, without success. A local resident who washed his car knew absolutely nothing. Finally I tried door knocking in the house that seemed most likely to me. Only an elderly lady opened the door for me, I explained my concern. “There’s no such thing here”, she said in the best ruhrgebiet dialect. I noticed that I had to catch the train back to Cologne and started the way home unsatisfied. Probably the sonde had come down in the garden plots behind the houses to which I had no access.

My First Sonde

#1 Essen – Breckerfeld
Vaisala RS41-SGP / P2740506 / 17.09.2018 1200Z
🔗 wetterson.de in storage
🔗 radiosondy.info individual transport

For a few weeks I had been waiting for an Essen sonde to land near Gummersbach. flynamic, which I had infected with my probe fever, was on board within a radius of 40 km. On the first day of the math precourse at my university, in which I participated every year as a tutor, it finally happened, and P2740506 landed in Breckerfeld, a little further than 40 km away. ON-1 lost the signal at over one kilometre altitude, it would either be a forest landing, or the probe would have made it to a meadow in the valley.

During the tutorial a short arrangement with flynamic, who picked me up at the TH around 17:00 o’clock. We drove briefly by my home to pick up the big Yagi, because the Moxon was still relatively new and I wanted to be on the safe side.

After our arrival at the hiking car park the disappointment followed while decoding: The probe had landed a few hundred meters before the meadow in the forest. We went to the landing point. The closer we came, the greater my excitement was. We hit into the forest and had luck: in the high spruce trees the probe dangled in approx. 2 m height and waited to be picked by us. Parachute and balloon remainings were inaccessibly high, and thus we went, highly pleased, with a probe in the luggage under a dreamlike sunset back home.