On April 7th the PI9CAM team hosted some students, working on a film project. So there was some spare time to schedule more tests in our space debris project. The objects, selected to try on, were some rocket bodies. Many of the larger objects in low earth orbits are of this type. The operation style, as usual, was a center frequency of 1,296.300 MHz, 15 seconds periods with DJ5AR transmitting first. This time we wanted to try FSK441 mode, to compare it with the experiences, we had with ISCAT-B.
On two objects, NORAD #39679 (SL-4 R/B) and #39771 (H-2A R/B) we registered faint but continuous reflections. Only partial decodes were possible. It seems, that ISCAT-B is the better choice.
Reflections of DJ5AR in FSK441 recorded at PI9CAM
On SL-4, a russian rocket body, lauched on April 16th, 2014, a modulation of the reflections with a period of 2.8 seconds could be observed. It looks like, as the object is tumbling.
Josemi, EA2TZ, informed me about the new setup of his beacon EA2TZ/B on 1,296.855 MHz.
The antenna is a stacked 2 x big wheel now, omnidirectional and the power is 10 W. The location is in about 630 m asl in IN93BF88CP, east of Bilbao.
Reports are welcome!
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.
Jürgen, DK2AN phoned me tonight, to tell me, the new beacon DB0XY will be transmitting on 1296.910 MHz. It is located on the Bocksberg in the Harz mountains in JO51EU, about 750 m asl. The power is 10 W into a 4 times double quad, omnidirectional. The keying is in A1: callsign, locator, carrier, dashes, carrier….
In a first quick try it could be received here with 519 to 539 via tropo. When Planes crossed the path, the signal increased up to 559.
Another beacon will be installed on 13 cm soon. The intention is to provide beacons for monitoring via aircraft scatter.
September 27th, 2014 at the “Distriktsservicetag” of DARC districts K (Rhineland-Palatine) and Q (Saarland) in Saarbrücken.
I will talk about how to surmount the horizon on VHF and up.
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.
For the short version in Weinheim the overview over the classic propagation modes will be left out.
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.
One of my favourite beacons to be watched via aircraft scatter is PI7ALK in JO22IP. The beacon is running 4 W to a 4 times stacked omnidirectional antenna as described in DJ9HOs “UHF Unterlage V” on page 1001. The design of the antenna is by DC0BV. More details and the history of the beacon can be found here.
After about a minute first reflexions can be seen. The signal is increasing in strength, until the plane reaches the midpoint of the path. While other planes join, the signal will be spread by the doppler effect.