After I started with Lora and MeshCom devices I remembered that meteorological radiosondes operate close to 70cm Ham radio band. QRG used for radiosondes are 400-406 MHz. Firmware for 400 MHz Lora devices is availble for this application as well. So, I started with such a devices too. And it worked. However, I was not very impressed with the RX results. Then, I remembered, that I still have two RTL SDR sticks available which I used in the past as ADSB RX. Since June this year I have been using these two RTLSDR sticks with a Raspberry 4 and X-5000 antenna. Results are good and now I am looking forward for some good tropo condx in October. I guess that ODX >800km should be possible.
