A widespread high pressure system settled down over Europe in the middle of October 2017. It brought a summer-like weather to Poland with temperatures as high as 26°C measured in Wrocław. Excellent weather conditions, so called a Polish golden autumn, continued for several days. When the atmospheric pressure started to decrease again, the wind had also weakened. This provided favorable circumstances for temperature inversions and tropospheric ducting on VHF, UHF and microwave radio bands.
I have been observing propagation conditions within WLAN frequencies for many years. The 5 GHz band is very crowded in Poland, as it is widely used by the internet service providers with outdoor devices installed on tall buildings like chimneys, blocks of flats or lattice masts. In 2015 I detected some networks from Southern Poland and Czech Republic. I also fixed my personal reception record at 346.5 km. Since then I have started saving money for a taller mast, because the antenna (8 m AGL) was looking mostly at trees that greatly attenuate all microwave signals.
At the beginning of October I finally finished a new 18 meter mast with a parabolic dish for the 5 GHz band. Ubiquiti RocketDish 5G31-AC is a dual polarization 5.1-5.8 GHz antenna rated at 31 dBi. It is connected to MikroTik Routerboard RB912UAG-5HPnD radio behind the dish in a custom aluminium box. The mast is equipped with a rotator and everything can be remotely controlled.