5 GHz Wi-Fi DX record – Denmark logged in Poland @ 745 km

A remarkable tropospheric ducting occurred on August 11 and 12, 2020 between Poland, Sweden and Denmark. The propagation forecasts, which use color hue to scale their intensity, featured red shades over the Baltic Sea. Such a propagation strength is very rare, if ever seen on a forecast for this area. I was looking forward for something extraordinary, especially on the microwave bands. My stationary Wi-Fi DXing setup has been damaged three months ago. I could not miss such an opening, so a DX-pedition was the only option. In the evening of August 11 I made an opportunistic decision to visit the Dylewska Góra in north-eastern Poland. A few hours later, I was standing there with an antenna inside a lookout tower. 

With its tip at 312 m ASL, Dylewska Góra (Dylewska Mountain) near Ostróda is the highest hill of the whole north-eastern Poland. There is a wooden lookout tower atop which provides fantastic unobstructed views between 175° to 340° azimuth with optical visibility up to around 50 km. The driving distance from my location is 135 km and I arrived there in two hours, in the middle of the night (2 AM). I knew that place as I have visited it already once with my friend. Back then in the 2018 we encountered a typical morning inversion without any notable long-range ducting (see the report: Early morning on Dylewska Góra).

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New Year 2020: Excellent inversion over Poland

Ten wpis jest dostępny także w języku polskim: Nowy Rok 2020: Rekordowa inwersja nad Polską

This year’s winter in Poland has been very mild so far and it does not resemble this season in our country at all. In fact, it is more like late autumn with possible light frosts. The forecasts for January are still in line with current weather, so this month will be definitely warmer than average. Starting from the end of December 2019, subsequent high pressure systems began to move to Poland. Such weather favors good propagation conditions, which can significantly increase the range of radio emissions. An inversion in the troposphere can enhance the reception within a wide frequency range, starting from the lower VHF (typically 50-70 MHz), through broadcast radio, television, microwaves and finally even… optical waves.

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Nowy Rok 2020: Rekordowa inwersja nad Polską

This post is also available in English language: New Year 2020: Excellent inversion over Poland

Tegoroczna zima wcale nie przypomina tej pory roku w naszym kraju. W rzeczywistości nadal trwa późna jesień z możliwymi słabymi przymrozkami. Obecne prognozy nie pozostawiają złudzeń i w większości styczeń ma być bardzo łagodny. Od końcówki grudnia 2019 roku z zachodu zaczęły nadciągać nad Polskę kolejne wyże. Taka pogoda sprzyja podwyższonej propagacji, która potrafi w znaczny sposób zwiększyć zasięg emisji radiowych. Inwersja w troposferze może wpływać na odbiór w szerokim zakresie częstotliwości, zaczynając od dolnego UKF-u (typowo 50-70 MHz), przez pasma radiowe, telewizyjne, mikrofale, a nawet… widmo optyczne.

Mój zestaw odbiorczy to antena RocketDish 5G31-AC + DBII F52N-PRO na maszcie 18 m n.p.t. z rotorem w okolicach Płocka (114 m n.p.m.).

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Warflying (Wi-Fi scanning) in an airplane up to 450 km

Recently I was traveling by plane over Europe. Of course, I could not resist to check what could be received on 5 GHz there, at an altitude of over ten kilometers…

I took the following equipment for Wi-Fi scanning onboard:

  • Mikrotik Routerboard SXT 5HPnD (AR9280),
  • Raspberry PI 3B with GNSS receiver, RTC and 10 V PoE output – see more: Wardriving @ 5 GHz,
  • USB power bank (5V/2.1A),
  • Nexus 7 tablet.

I was scanning using MikroTik SXT antenna with a built-in radio module. This device is as small as 14×14 cm. The dual-polarization antenna rated at 16 dBi is even smaller, at just 11×11 cm. It was connected to Raspberry PI single board computer.

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