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.