After installation of new transverters for 23 and 13 cm with stabilized LOs a couple of months ago. I gathered some experience in using JT65C mode on EME. So I undertook a new attempt to receive and decode G8MBU via aircraft scatter today. As antenna I use a 3 m dish with a dual band ringfeed.
Path DJ5AR to G8MBU
The beacon is located at Cowes on the Isle of Wight, IO91IR37, 683 km from Mainz, JN49CV. It runs 2 W power into an omnidirectional dual alford slot antenna. The mode used is JT65c. Nominal frequency is 1296.800 MHz. To successfully decode the signal, the SSB dial should be set to 1296.7986 MHz, to get a tuning tone of 1400 Hz in WSJT.
There is a small window between the Isle of Wight and Mainz, where high flying aircraft can be “seen” from either places. But only a few airplanes cross the path within and fewer fly along the path. Reflections of G8MBU could be seen from time to time, but mostly too weak and too short to provide decodes. It took nearly 3 hours until the first decode happened at -22 dB and just some minutes later a second one appeared on the display at -21 dB:
Most spectacular is the ability to track airplanes with the antenna in azimuth and elevation. When enabling tracking, the user can select between several interfaces. I am using the plain WSJT-compatible “azel.dat” file. First tests on DB0NCO are very promising.
AirScout is not operable at present, due to changes at the data source. Frank, DL2ALF, is active to solve the problem. No planes will currently be shown in the map. If any news available, I will post it here and in the Microwave DX Group on Facebook.
My presentation “Let´s Bounce” will be given on two more dates:
October 25th, 2014 on the 4th Hessian GHz Meeting in Fernwald
Short version of the lecture with focus on aircraft scatter and ISS bounce.
We meet at 15:00 MEST on the car park at the town hall. There will be a flee market for GHz stuff and the opportunity to test own equipment or to have QSOs with other participants.
After my complainments about using the ON4KST chat in March Contest and the response I received from Claus, OZ1FDH, and Kjeld, OZ1FF, recommending the KST2ME tool, I added my homebrew prototype of a selective ON4KST client extension to my station control software. It communicates via telnet with the server. While working satisfactorily under normal circumstances, it was a desaster under contest load. When the software didn´t crash, it at least slowed down, by computing hundreds of posts in shortest time. Between 300 and 400 users have been logged to the microwave chat during contest time. During the first contest hours I tried to solve the problems with certain bug fixes, resulting in a huge loss of contest time. So I had to return to the classic style in using the web client of the chat.
QSOs on 23 cm
In total I logged 73 QSOs on 23 cm to 12 DXCC countries, spread over 39 grid squares (results). ODX was HG7F over 817 km. The use of the AirScout software, written by Frank, DL2ALF, has been essential. Most of the QSOs have been completed by assistance of aircraft scatter.
A nice example is the one with DJ5BV in JO30KI. The distance isn´t really far enough to do it via aircraft sctatter, but it seems, both antennas were pointing west and that resulted in effects of aircraft backscatter with significant dopplershifted reflections.
Dopplershifted reflections of Gerd, DJ5BV, caused by backscatter of aircrafts.
On July 24th, 2014 on 19:00 CEST I will talk about how to surmount the horizon on VHF and up at the local DARC Club in Bodenheim near Mainz.
After giving an overview over the classic propagation modes Es, Aurora, MS and Tropo, I will explain, how aircraft scatter and ISS bounce work. EME will be subjected too and the presentation will be completed by an introduction to “Visual Moonbounce” as performed by Daniela de Paulis.
Deutscher Amateur-Radio-Club e.V.
Haus der Vereine
Laubenheimer Str. 22
The admission is free, but please register via email to
DK2FQ wolfgang.beer (at) gmx.net or to me dj5ar (at) darc.de
German Funkamateur mgazine has published my article “Abenteuer Bakenbeobachtung von 144 MHz bis 10 GHz” in its recent issue July 2014. As many topics are related to posts on this website, some of them are compiled here. Links to certain other websites can be found in the link list to the right.
Thursday night I tried a QSO on 23 cm with DG2PU in JO30PH, what´s a distance of only 80 km. Unfortunately Thomas is located down in a valley with Taunus and Hunsrueck mountains between us. His neighbor Marcel, DK7UP is closed by, but up on a hill. While it´s no problem to contact Marcel on 23 cm, Thomas signal was only 41, peaking 51 from time to time. Since beacons in similar distances often produce nice signals via aircraft scatter here, I suggested to try a QSO using airplanes to get reflections, but Frankfurt airport was already closed at that time that there was only very little air traffic. So we tried this evening. Our antennas were elevated by about than 10°, because the hot spot was in a distance of only 40 km (and a heigt of 10.000m). The second plane passed by in perfect manner and I could copy Thomas for about 10 to 15 seconds with 57, enough to complete a QSO. Due to the short distance the hot area around the center of the path is relatively small and reflections will not last too long.