Category: Wi-Fi DX

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).

Out of the four seasons, autumn is well known among radio enthusiasts as the best period for spectacular propagation of radio waves. The tropospheric ducting is a propagation mode based on temperature inversion in the vicinity of the Earth’s surface. Such an enhancement extends the regular line-of-sight distribution of electromagnetic waves to the areas out of their general, daily service. During special conditions, air layers may form some kind of a guide for the radio signals. This phenomenon usually happens during periods of stable anticyclonic weather and affects radio frequencies in VHF, UHF and microwave bands. While it is possible to watch distant TV channel or listen to a foreign FM station, one can also check other, less explored radio frequencies… like the 5 GHz band widely used for the wireless LAN communication.

This year was really extraordinary in Poland. The spring was very amazing, as both April and May smashed through all previous temperature records. We have also experienced the warmest summer, at least since the beginning of measurements in 1781. Such weather allowed often occurrence of radiation inversions that produced good tropospheric propagation throughout nights and mornings. I set my previous personal Wi-Fi DX reception record in May twice in a row from Wolin, Poland during unattended scanning on 2018-05-28 and 2018-05-29 mornings, at a distance of 370 km.

In the first half of October 2018, a high pressure system settled down over Eastern Europe and brought excellent propagation conditions in Poland. Again, the summer-like weather brought sunny days and 20-25 °C temperatures. This time I logged some networks from Ukraine, Lithuania and almost… 3600 other from Poland.

Ten wpis jest dostępny także w języku polskim: Poranek na Dylewskiej Górze

On Thursday, August 16, 2018, our team visited Dylewska Góra. The trip was somewhat spontaneous, although we have been considering it for a long time. Weather forecasts looked good, so in the evening of the day before we decided to visit this remarkably interesting place in the Warmian-Masurian Voivodeship, Poland.

Dylewska Góra is the highest hill of Wzgórza Dylewskie and of the entire north-eastern Poland. The peak with an elevation of 312 m ASL is located in Wysoka Wieś, south of Ostróda. There are three interesting objects there:

• the radio tower Ostróda – Dylewska Góra (Emitel),
  
• concrete observation tower,
  
• wooden lookout tower.

Nearby, one can also notice some residential buildings and farmlands.

Unfortunately, the 37-meter high concrete observation tower is not available to tourists. The alternative wooden tower is much lower and does not provide a full view around the hill, because the eastern view is obstructed by tall trees. Access by car is possible to the very end. In the immediate vicinity of the tower there is no place to park though. An undoubted advantage is the possibility of getting there at any time of day or night, as the entrance to the wooden tower is free and available to everyone. It was very important for us, because we wanted to catch the morning inversion that extends the standard radio range in some way…

We took some equipment for 5 GHz, including:

• parabolic dish antenna UltraDish TP 550 (27,5 dBi) with RB911G-5HPnD radio,
• panel antenna Routerboard QRT5 (24 dBi) also with RB911G-5HPnD,
• tripod, laptops, cables, batteries… and of course the camera.