Moon Bounce out of the Boot

September 28th, 2019

On the annual service day of the DARC districts Saarland and Rhineland-Palatinate I had the pleasure to hold a lecture about EME basics and how to get into. Afterwards I invited the audience to try a live moon bounce QSO on 432 MHz from the parking lot outside. I had prepared some standard equipment of the kind, many might have in their shacks:

  • Transceiver Yaesu FT-897
  • 15-Element Yagi (YU7EF )
  • PA Gemini 70, ca. 200 W
  • LNA SHF-Elektronik, 0,8 dB NF
EME rig in the boot, Photo by courtesy of Klaus, DF6WN

Unfortunately it was rainy outside, the moon close to the sun and a G2 solar storm in progress. When swithing on the transceiver, I noticed some quite massive local QRM. Nevertheless I contacted Bernd, DL7APV, who had agreed in a sked, by phone, to tell him about the noise and that we were ready to go.

Bernd´s array of 128 x 11 elemnt yagis during a barbeque last June

As the noise level went up and down and Bernd is one of the big guns on 70 cm, we were able to decode most of his transmissions despite all adversities. Finally we completed the QSO. That was a great job, Bernd!

I enjoyed to be in Saarbrücken and would like to say thank you to Eugen, DK8VR and his team for organising DST 2019!

After a Year of Absence: Back in Business!

July 7th, 2019

The last contest, I participated, was in June 2018. There wasn´t much time for amateur radio since. So I was lucky to dive into contesting this weekend mainly on 23 and 13 cm, as usual, but had some QSOs on 2 m, 70 cm and 3 cm as well.

I am happy about 60 claimed QSOs on 23 cm and 43 on 13 cm. On 3 cm I logged 7 Stations, with OE5VRL/5 as ODX via rain scatter.

QSOs on 23 cm
QSOs on 23 cm

There have been some new calls on 23 cm but none on 13 cm, as I had expected. Many became QRV on 2400 MHz for QO-100, using transverters, also operable on 2320 MHz. They should learn about the exitement of DX via aircraft scatter on 13 cm.

QSOs on 13 cm

F1ZBK in JN38BP back on air on 1296.854 MHz

June 7th, 2019
Doppler shifted traces (1000 Hz = 1296.854 MHz)

When looking for EA2TZ/B during a beacon check a couple of days ago, I mentioned a signal with strong doppler shift about a khz below. As I like the challenge to identify new beacons, I started monitoring it. It became a kind of a nightmare, trying to to catch the beacons callsign. It seems to be very chatty, transmitting a whole bunch of unuseful text. despite the fact I got a lot of good quality fragments via aircraft scatter, it took me hours to identify it as F1ZBK. At least I am pretty sure it is, as there is a second callsign in the end of the text: F1DND, maybe it´s the keepers call.

The text decoded so far is:
—— beacon f1zbk jn38bp nancy … 854 khz … 5 watt … f1dnd … orange KA … ——-
Where the “…” represent gaps and KA is the prosign for “Attention” or “New Message” (not to be used at the end of a message, like AR).

There are many beacons running in bad modes like reversed F2A or keying the subcarrier of F2A, but transmitting such a lot of stuff is worse.

It would be a great advantage, if all beacon keepers will respect the beacon requirements as published in the VHF Handbook of IARU R1.

Playing with the bird

April 1st, 2019

As soon, as the narrow band transponder was opened in February, I had my first QSOs via QO-100. Using an MKU LNC 10 in a 80 cm offset dish and my 3 m mesh dish for transmitting, made the first steps very (too) easy.

ADALM Pluto and 2 LNAs mounted at a W2IMU feedhorn

In the meantime I mentioned, some hams from the Netherlands, experimenting with ADALM-Pluto SDRs, had very good results. So I got one too and was amazed of variety of possibilities it offers. So I heard my first beacon on 9 cm and it was easy to produce a signal on 13 cm. Recently I got two broadband LNAs (I will call them “A” and “B”) from China and was curious to see how these can be used as power amplifiers too.

Power SourcePower in mW
Pluto 3
Pluto + LNA "A" 22
Pluto + LNA "B" 30
Pluto +LNA "A" + LNA "B"120

After some power measuring I connected the stuff to a W2IMU feedhorn, mounted on a tripod. No problem at all to find my signal on the NB transponder of QO-100. The estimated EIRP is about 2.4 W and results in a signalstrength of 12 dB.

Addendum: April 10th, 2019

3 mW are enough!

At least I mounted a DJ7GP patch feed with the bare naked Pluto in the focus of my 3 m mesh dish. the 3 mW were enough to produce a solid signal on the NB transponder. In this case I have 6 W EIRP to get 16 dB signal.

Nice surprise

March 13th, 2019

It was a nice and not anymore expected surprise, as the postwoman had a thick envelope for me: An award for the IARU Region 1 UHF/Microwave contest in October 2017. In it´s attractive design it is an enrichment for my collection.

2017, October: 1st in IARU R1 UHF/MW Contest, Single 2,3 GHz

OK0ER via Aircraft Scatter on 13 cm

October 22nd, 2018

As OK0EA was audible this morning on 23 and 13 cm I had a look for other, more distant beacons in OK. After noticing a very short and weak signal on 2320.9085 MHz, I monitored the frequency over a couple of hours and saw many doppler shifted traces, typical for aircraft scatter. Very soon I copied “…9DP…”, when a B777 crossed the path and was sure to see OK0ER in JN99DP in the waterfall diagram. At least 4 Airbuses A380 crossed the path one after the other, giving nice reflections.

OK0ER transmits 1.5 W into a slot antenna in 675 m asl. The distance is 722 km.


New 13 cm WebSDR in Eindhoven JO21RL

September 9th, 2018

Rob, PE1ITR, told me about a planned WebSDR for 2.3 GHz in Eindhoven, when we met recently at the EME conference. He promised to send an email, as soon as it is up and running:

Needless to say, the email arrived and I turned my dish to Eindhoven. Now I am delighted by my own signal. Amazing to see it increasing by reflections on an A380 passing the path, while two Dutchmen are talking a little lower in frequency.


Longjiang-2 S-Band Beacon received over 400000 km

January 10th, 2019

As I digged a little deeper, I learned, the source of the signal on 2275,225 is not Queqiao, but it is it´s companion Longjiang-2 or DSLWP-B in an orbit around the moon.

August 23rd, 2018

Designed as a relay for the planned chinese Chang’e 4 misson to explore the far side of the Moon with a lander and a rover, the Queqiao probe has reached it´s final destination 60000 km behind the Moon. There it is in a halo orbit with a radius of 15000 km around  the Langrangian L2 point of the Earth-Moon-system. So it won´t be covered by the Moon, seen from Earth.

Queqiao also carries a radio astronomy experiment for low frequency exploration in collaboration with dutch ASTRON. After the lainch in May 2018 two microsatellites Longjiang-1 (DSLWP-A) and Longjiang-2 (DSLWP-B) were released, to enter orbits around the moon. These satellites carry a radio astronomy experiment as well as amateur radio payloads. While Longjiang-1 went lost, Longjiang-2 is operating and can be monitored in the 70 cm band as well as in the S-Band.

The signal of the S-band beacon is audible at about 2275.225 MHz. The used equipment is HDSDR software with a RTL-SDR-Stick connected to a 13 cm ATV Converter (LO=916 MHz) and a 13 cm LNA (Kuhne) at a 23/13cm dualband ringfeed in my 3 m dish.

Weltraumkinder schicken Astro-Alex zum Mond (German)

August 2018

Großes Finale im Weltraum-Projekt zum Ende des Kindergartenjahres!

Seit dem Auftakt mit einer Mondbeobachtung an der Paul-Baumann-Sternwarte der Astronomischen Arbeitsgemeinschaft Mainz e.V. im April konnten die Kinder viele Eindrücke vom Weltraum und dem Leben der Astronauten auf der Internationalen Raumstation sammeln. Sie absolvierten ein Raumfahrer-Training und stellten selber Astronauten-Nahrung her. Es wurde der Flug von Alexander Gerst zur ISS verfolgt und eigene Brausepulver-Raketen gestartet. Warum Funkverbindungen hinter den Horizont schwierig sind, konnte mit Walkie-Talkies selbst ausprobiert werden. Und nicht zuletzt war dann Astro-Alex selbst live per Amateurfunk von der Raumstation zu hören, als er Fragen von Schülern von Schulen in Leverkusen und Herrenberg beantwortete.

Bild: Alexander fliegt zum Mond (Ben Brinkhus)

Da der Mond ein erklärtes Ziel von Alexander Gerst ist, haben die Kinder dann Bilder gestaltet, die ihn auf dem Weg zum Mond zeigen. In Interviews erzählt er gern von seinem Opa, der als Radioamateur Funksignale am Mond reflektieren lassen konnte, was den jungen Alexander seinerzeit immens beindruckt hat. Deshalb wurde eins der Bilder ausgewählt und zusammen mit einem Foto von ihm, seinem Missions-Logo und dem Logo der Kindertagesstätte St. Laurentius ging es auf die Reise nach Italien zu Nando Pellegrini, der als Funkamateur unter dem Rufzeichen I1NDP eine große Sendestation betreibt. Mit seinem Parabolspiegel, der einen Durchmesser von 10 m hat, sendete er die Bilder im 23 cm Amateurfunk-Band im sogenannten Slow-Scan-Television-Verfahren, ähnlich einem FAX, in Richtung Mond. An der Oberfläche unseres Trabanten wurde die Funksignale reflektiert und trafen zweieinhalb Sekunden später mit Lichtgeschwindigkeit wieder auf der Erde ein.

Bild: Radioteleskop in Dwingeloo

Hier hatte sich das historische Radioteleskop in Dwingeloo in den Niederlanden bereitgehalten, um die Bilder nach ihrer Reise über fast 800.000 km wieder aufzufangen.Betrieben wird die denkmalgeschützte Einrichtung in der Provinz Drenthe im Nordosten der Niederlande von der CAMRAS Stiftung, in der eine große Zahl von Funkamateuren mitarbeitet. Hier, an der erst vor fünf Jahren aufwändig restaurierten Parabolantenne von 25 m Durchmesser, haben die italienische Künstlerin Daniela de Paulis und der niederländische Funkamateur Jan van Muijlwijk, Rufzeichen PA3FXB, im Jahr 2009 das „Visual Moonbounce“ genannte Verfahren entwickelt, bei dem sie im Rahmen von Kunst-Projekten und Astronomie-Events der „Astronomers without Borders“ mit Hilfe geeigneter Gegenstationen in Italien, Brasilien, Großbritannien und der Schweiz Bilder am Mond reflektiert lassen.

Dank guter persönlicher Kontakte konnten die beteiligten Funkamateure dafür gewonnen werden, die Bilder der Ebersheimer Weltraumkinder im Rahmen einer öffentlichen Veranstaltung in Dwingeloo zum Mond zu schicken, um den dortigen Besuchern „Visual Moonbounce” eindrucksvoll zu demonstrieren.

Bild: Alexander Gerst (ESA)

So kam es, dass nicht die ESA, sondern die Weltraumkinder der Kindertagesstätte St. Laurentius in Mainz-Ebersheim Alexander Gerst zum Mond geschickt haben.Wir danken Daniela de Paulis, Jan van Muijlwijk, Nando Pellegrini sowie dem Team CAMRAS für die Unterstützung unseres Weltraum-Projekts! Das Bild vom Flug zum Mond hat das Weltraumkind Ben Brinkhus gestaltet.

Ansprechpartner für das Weltraum-Projekt: Regina Imse,
Kath. Kindertagesstätte St. Laurentius, Großgewann 2,
55129 Mainz-Ebersheim

Zeichnung „Alexander fliegt zum Mond“: Ben Brinkhus
Alexander Gerst, Horizons-Logo: ESA
Radioteleskop Dwingeloo: Andreas Imse
Logo der Kindertagestätte St. Laurentius, Mainz-Ebersheim
Reflektierte Bilder: Nando Pellegrini und Team CAMRAS