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’ve been observing propagation conditions on the WLAN frequencies for many years. The 5 GHz band is very crowded in Poland, as it is widely used by the ISPs (Internet Service Providers) with outdoor devices. The antennas are installed frequently on tall buildings like chimneys, blocks of flats or lattice masts. In autumn of 2015 I have detected some networks from Southern Poland and Czech Republic at distances over 300 km. I also fixed my personal reception record at 346.5 km, but it was just a single received packet I think. 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 75 cm parabolic dish for the 5 GHz band. Ubiquiti RocketDish 5G31-AC is a dual polarization antenna for 5.1-5.8 GHz band with 31 dBi gain. It is connected to MikroTik Routerboard RB912UAG-5HPnD 2×2 MIMO radio behind the dish in a custom aluminium box. The mast is equipped with a rotator and everything can be remotely controlled. The view at this height is now unobstructed in almost all directions at low elevation angles (1-2°, locally 0.5° or better). My antenna is located near Płock in Central Poland.

  

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The forecasts suggested some upcoming long-range tropospheric ducting from Sweden, Norway and Finland in October. According to maps, as usually, the strongest tropo was expected over the Baltic Sea, with just marginal strength extending to my location. Nevertheless I was prepared to check the propagation conditions remotely.

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mapThis is the continuation of the article: August 2016: extreme VHF tropo (F, HRV, BIH, I) – part I.

August 26, 2016 was definitely a remarkable day for the European long-range tropospheric propagation. Zagreb was logged in Finland by several DX-ers, up to 1691 km, however in Poland the best conditions occurred one day later, on August 27th.

But first, let’s go back in time to the year 2014 when I wrote an article titled Autumn Tropo 2014 (D, HRV, SVN…), especially to the last paragraph:

Italy was very close this time, as the tropo ducting would have to cross only the Adriatic Sea. Unfortunately, all interesting frequencies were overtaken by closer stations here in Płock. The closest Italian locations are blocked by the Alps, but maybe someday we could receive it in Poland across Croatia and Adriatic Sea instead…?

The described path, across Adriatic Sea, was just a wishful thinking and actually I have never expected it to occur. Well, guess what happened… Read more / Czytaj dalej →

August 2016 started with a cold and rainy weather, which continued for more than half of the month. It had some advantages though, as the radio band was clear of tropo signals during peak of the Perseids. Thankfully, the end of August was much more exciting and brought a superior tropospheric ducting propagation conditions. It started with distant Germany, Denmark, Sweden, AustriaFrance and then, after three days, moved more into central Europe, to a completely unexpected set of countries: Slovenia, CroatiaBosnia and Herzegovina and… ITALY!

Long range tropospheric ducting was lasting this time for 6 days – starting from August 23 until Sunday, August 28. Because of a very high amount of notable DX receptions, this article describes only the first three days of this awesome tropo opening. Read more / Czytaj dalej →

The weather in first days of summer brought a widespread high pressure system that has settled down over Eastern and Central Europe. Very good tropospheric conditions were forecasted between Germany, Switzerland, Czech Republic and partially Poland. 

In the evening on June 23, I quickly checked the signals before sleep. There was nothing interesting on the 87.5-108 MHz band… except one low modulated station on 107.3. I have already received hr4 from Germany on this frequency twice before, but with weak signal levels. I was quite busy, so I kept the 107.3 tuned for any upcoming identification. In a moment I saw a PI code: D704. Well, that was odd, because I thought that hr4 carries a different PI code. And I was right, shortly I heard an ID – SWR4 verkehr! So, this time I got Raichberg @ 898 km on this frequency. Read more / Czytaj dalej →

I am pleased to announce that the long-awaited 1.0 version of XDR-GTK has just been released. As usually, XDR-I2C upgrade to the latest version (2016-04-20) is also required.

xdr-gtk-1.0

The main window contains new interference detectors: CCI (co-channel) and ACI (adjacent channel) which make the antenna pointing easier for the best signal to interference and noise ratio. Read more / Czytaj dalej →