The beginning of December brought an unexpected tropospheric propagation. The weather was influenced by high pressure and it was rainy. In the evening on December 2nd, 2015 I noticed some distant signals. When I checked my tuner remotely, FM4 from Salzburg was already at stereo + RDS level. In just a hour I also heard Wendelstein, Hornisgrinde, Bregenz, Grünten, Säntis and the furthest location – Rigi @ 1015km, which I logged for the first time.
This recording also includes a comparison with the webstream at 00:04. Thanks to bad local propagation conditions I easily attenuated RMF FM signal from Piła/Rusinowo on the same frequency as 96.6 SRF 2 Kultur.
Tropo from Switzerland is quite rare here in Poland, because mountains ranges on the Czech Republic border are obstructing this direction. However, Säntis ducted once before in 2011 and the signal reached RDS level at peak! This time tropo was weaker and patchy, except Salzburg with quite strong, but also unstable signal.
Bregenz recordings are included in my log: Bregenz – Pfänder, Austria (908 km).
December 2, 2015 – logs:
|1917||104.6||FM 4||AUT||Salzburg/Gaisberg||100||712||A213 __FM4___|
|1920||101.8||Antenne Salzburg||AUT||Salzburg/Gaisberg||10||712||jingle ID 23dBf|
|1926||88.7||Bayern 2||D||Grünten (Allgäu)||100||876||15dBf|
|1935||98.4||SWR 3||D||Hornisgrinde||80||927||SR3 jingle (not SWR) 30dBf|
|1936||96.2||SWR 2||D||Hornisgrinde||80||927||D3A2 29dBf|
|1951||101.5||SRF 1||SUI||Säntis||60||952||//web Mrs. Robinson song|
|1955||106.5||Antenne Vorarlberg||AUT||Bregenz/Pfänder||50||908||jingle ID [1st]|
|1956||89.6||Hitradio Ö3||AUT||Bregenz/Pfänder||50||908||weak //99.0 [1st]|
|1958||102.1||FM 4||AUT||Bregenz/Pfänder||50||908||20dBf //104.6 [1st]|
|2007||106.9||B5 aktuell||D||Grünten (Allgäu)||100||876||mono ~19dBf|
|2008||95.8||Bayern 3||D||Grünten (Allgäu)||100||876||//98.5|
|2019||96.6||SRF 2 Kultur||SUI||Rigi/Kulm||30||1015||//web ~14dBf [1st]|
|2043||99.0||Hitradio Ö3||AUT||Salzburg/Gaisberg||100||712||A203 36dBf|
|2045||94.8||Ö2 – R. Salzburg||AUT||Salzburg/Gaisberg||100||712||A802 Radio_S_30dBf|
It was definitely some kind of a very highly elevated tropospheric duct. Both F5LEN’s and William Hepburn’s forecasts did not predict any extended propagation conditions between Switzerland and central Poland.
The high pressure system that developed such extraordinary tropo can be seen on the following maps: